0-9 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
A-Z reference for the terms, acronyms and standards you'll come across across Australian industrial, trade and maintenance work — bearings and power transmission, fasteners, cutting tools, welding, pneumatics, safety and PPE, and everything else AIMS supplies. Jump straight to a letter below, or use your browser's find function to search this page.
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What Is 304 Stainless Steel?
304 stainless steel (roughly 18–20% chromium, 8–10.5% nickel, no molybdenum) is the general-purpose austenitic grade used across food and beverage, indoor industrial and dry or occasional-splash corrosive environments — the standard, lower-cost grade against which 316 Stainless Steel is the marine-grade upgrade.
A quick field test many trades use: 316 is noticeably less magnetic than 304, so a strong rare-earth magnet grips 304 firmly but only weakly on 316 — useful for a rough check when a certificate isn't on hand, though it's not a substitute for proper material certification on critical applications.
Read AIMS's full Stainless Steel Fastener Grades guide →
Shop AIMS's range of stainless link chain →
What Is 316 Stainless Steel?
316 stainless steel takes the same base composition as 304 Stainless Steel and adds 2–3% molybdenum, and that single addition materially improves resistance to chlorides and salt water — which is why 316 is the standard upgrade for marine, coastal and washdown-chemical environments where 304 alone would corrode faster.
A quick field test many trades use: 316 is noticeably less magnetic than 304, so a strong rare-earth magnet grips 304 firmly but only weakly on 316 — useful for a rough check when a certificate isn't on hand, though it's not a substitute for proper material certification on critical applications. Even 316 has a limit in extreme, sustained saline exposure — see Duplex Stainless Steel for the grade that's specified beyond that point.
Read AIMS's full Stainless Steel Fastener Grades guide →
Shop AIMS's range of stainless link chain →
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What Is A/F (Across Flats)?
A/F (Across Flats) is the measurement of a hex bolt head or nut, taken as the straight-line distance between two parallel (opposite) flat faces of the hexagon — it's the number that tells you which spanner or socket to grab.
A/F is a wrench-size measurement, not a thread size: an M10 bolt (10 mm thread diameter) typically has a 17 mm A/F head, so "10 mm" and "17 mm" both describe the same bolt but answer different questions. AIMS's metric bolt size guide lists A/F spanner sizes against thread diameter for the full M6–M36 range, and the same A/F system applies across both partial- and full-thread hex head bolt styles.
Read AIMS's full Metric Bolt Size Guide → for the complete A/F-to-thread-size spanner table
Shop AIMS's range of spanners & wrenches →
What Is an Abrasive?
An abrasive is a hard, sharp-edged material used to cut, grind, sand or polish another surface by mechanical friction rather than by a defined cutting edge. Abrasives fall into two broad families covered throughout this category: Bonded Abrasive products, where grain is fused into a solid shape (a Grinding Wheel or Cutting Disc), and coated abrasives, where grain is glued to a flexible backing (Sandpaper, a Sanding Disc or a Sanding Belt).
Shop AIMS's range of abrasives — cutting discs, sandpaper, burrs →
What Do Active, Neutral and Earth Mean?
Active, neutral and earth are the three conductors in a standard AU single-phase electrical circuit: active carries the current from the supply to the load, neutral completes the circuit back to the supply, and earth is a safety conductor that carries fault current away to ground rather than through a person in contact with the equipment. An RCD monitors the balance between active and neutral specifically to detect current leaking out through an unintended path — often via earth, or via a person — and trips the circuit before that becomes dangerous.
What Is Actuator Fail-Safe Mode? (Pneumatic Actuator)
Fail-safe mode describes what a pneumatic valve actuator does automatically if it loses air supply. A spring-return (single-acting) actuator uses air pressure to drive the valve one way and a spring to return it the other — air opens and the spring closes it (fail-closed), or air closes and the spring opens it (fail-open) — so on a genuine air-supply failure, the valve moves to its designated safe position without any external power or signal needed. A double-acting actuator has no internal spring: it uses air to drive the valve both ways, so on air loss it simply holds whatever position it was last in, sacrificing automatic failsafe for a lighter, cheaper actuator with higher available torque.
Spring-return is the standard specification for safety-critical isolation valves, hazardous chemical lines and fuel shut-offs, precisely because "fails in position" isn't good enough where a definite, predictable action is required the moment air pressure is lost. Whichever type is fitted, it still needs to physically bolt to the valve — see ISO 5211 Mounting Flange for the mounting interface standard that applies to both.
Read AIMS's full Valve Actuator Guide → for the full electric vs pneumatic actuator selection framework
Shop AIMS's range of pneumatic & linear actuators →
What Is AdBlue (Diesel Exhaust Fluid / DEF)?
AdBlue is a high-purity urea-water solution injected into the exhaust stream of modern diesel engines fitted with Selective Catalytic Reduction (SCR) — it reacts with the exhaust gases to break down harmful nitrogen oxides (NOx) into nitrogen and water vapour before they leave the tailpipe. It's a consumable, not a fuel additive — most SCR-equipped trucks and buses use roughly 3-5% as much AdBlue as diesel by volume, and running out triggers a progressive power derate rather than simply a warning light.
Shop AIMS's range of AdBlue and diesel exhaust fluid equipment →
What Is the ADG Code? (Australian Dangerous Goods Code)
The ADG Code — formally the Australian Code for the Transport of Dangerous Goods by Road & Rail — is the national regulatory framework governing how dangerous goods are packaged, labelled and transported across Australia. It's built on the same nine-class UN dangerous goods system used internationally (explosives, gases, flammable liquids, flammable solids, oxidisers, toxic/infectious substances, radioactive material, corrosives and miscellaneous dangerous goods), and compliance becomes mandatory once goods are transported or stored above set threshold quantities.
The ADG Code is maintained by the National Transport Commission and sits alongside — but is legally distinct from — a workplace's broader WHS obligations around hazardous substances and hazchem signage; a substance can trigger both frameworks at once, or just one. It's the standard behind the diamond-shaped hazchem/dangerous goods signage placement rules already covered in this glossary's Safety & PPE category, and the classification system that determines what goes on a dangerous goods storage cabinet, bunding or placard.
Read AIMS's full Dangerous Goods vs Hazardous Substance Guide →
What Is an Adhesive?
An adhesive is any substance used to bond two surfaces together by surface attachment rather than mechanical fastening — from general-purpose glues through to high-strength structural and engineering adhesives used in place of welding, riveting or bolting.
Industrial adhesives are chosen by cure mechanism, bond strength, gap-filling ability and the materials being joined — a choice covered in detail across AIMS's own adhesive range, from Anaerobic Adhesive threadlockers and Retaining Compound through to Cyanoacrylate (Super Glue / Instant Adhesive), Epoxy Adhesive (Two-Part) and Structural Acrylic.
Read AIMS's full Industrial Adhesive Types Guide →
Shop AIMS's range of adhesives, sealants & tapes →
What Is AGMA?
AGMA stands for the American Gear Manufacturers Association, a standards body whose lubricant viscosity classification system (AGMA numbers) is used specifically for gear oils and open-gear lubrication, alongside the more general VG (Viscosity Grade) system used for industrial oils broadly. It turns up in AIMS's own catalogue anywhere gearbox or open-gear lubrication is specified by an OEM to an AGMA number rather than an ISO VG figure.
What Is AIG? (Australian Industry Group)
In an Australian industrial context, AIG most commonly refers to the Australian Industry Group — a peak national employer body (branded "Ai Group") representing over 60,000 businesses across manufacturing, construction, defence, logistics and related sectors, providing workplace relations advice, safety guidance, training and industry advocacy.
Worth flagging plainly: "AIG" is a genuinely ambiguous acronym, and the bare letters are dominated in general search by the giant US insurer American International Group (also styled AIG), which has no connection to Australian industry at all. Ai Group itself doesn't commonly abbreviate to "AIG" in its own branding — it prefers "Ai Group" — so a reader searching the bare acronym is more likely hunting for the insurer than the industry body. Still, for a tradesperson, engineer or procurement professional across manufacturing, construction or logistics in Australia, Ai Group is a body worth knowing: it publishes the widely-cited Ai Group Performance of Manufacturing Index (PMI) and represents employer interests on industrial relations and trade policy that touch every business in MRO and OEM supply chains.
What Is an Air Brake System?
An air brake system uses compressed air, rather than hydraulic fluid, to apply a heavy vehicle's brakes — standard equipment on trucks, buses and trailers because compressed air can be split across multiple axles and trailers reliably, and a loss of air pressure automatically applies the brakes (fail-safe) rather than releasing them. Air is stored in reservoirs and delivered through Brake Chambers, which push a Slack Adjuster to rotate the S-Cam, forcing the brake shoes against the drum. Trailers connect into the tractor's air system through Glad Hand couplings.
What Is an Air Hammer? (Pneumatic Chisel)
An air hammer, also called a pneumatic chisel, is a reciprocating air tool that drives an interchangeable chisel, punch or cutting bit at 3,000–5,000 blows per minute — enough impact energy to drift a seized pin, break a corroded suspension joint loose, or chip weld spatter, jobs that would otherwise need a hammer and a lot of persistence. Air demand is modest and intermittent, around 3–4 CFM at 90 psi.
The safety point genuinely matters and isn't boilerplate: the bit is held in the tool by a spring or a hex shank with a snap-ring, and a bit fired at full velocity without that retention in place is a documented workshop injury pattern — into a floor, a panel, or worse. Always use the OEM retainer spring or snap-ring rather than running a bit loose "just for one job." Compare to Air Ratchet for fastener work where impact chiselling isn't what's needed.
Read AIMS's full Air Tools Guide → for bit retention types and blow-frequency specs
Shop AIMS's range of pneumatic & air tools →
What Is an Air Ratchet?
An air ratchet is a pneumatic ratchet wrench — a reversible air motor spinning a standard ratcheting head, built in ¼", 3/8" and ½" drive sizes for undoing and doing up fasteners far faster than a hand ratchet, and in a tighter working space than most cordless equivalents can manage. Typical air demand sits around 3–5 CFM at 90 psi (620 kPa), which is an intermittent, on-and-off load rather than continuous.
Its case against a cordless electric ratchet comes down to run time and simplicity: an air ratchet never runs out of charge and there's no battery to manage, charge or replace — the trade-off is being tethered to an airline and needing a compressor capable of at least 6 CFM to keep it fed. Most well-equipped workshops end up running both, reaching for air on the bench and cordless for anything away from a hose.
Read AIMS's full Air Tools Guide → for the full air-tool CFM reference table
Shop AIMS's range of pneumatic & air tools →
What Is AISC? (Australian Institute of Steel Construction)
AISC was the peak industry body for Australian structural steel engineers and fabricators until 2002, when it merged with the Steel Institute of Australia (representing upstream steel mills and distributors) to form today's Australian Steel Institute (ASI).
Worth flagging for anyone searching the acronym today: "AISC" now much more commonly refers to the American Institute of Steel Construction, a separate and still very active US body that publishes its own structural steel specifications (AISC 360) and construction manual — the two are unrelated organisations that happen to share an acronym. In Australia, the legacy AISC name lives on informally in the "AISC Design Capacity Tables" for open and hollow structural steel sections, still published (now under the ASI name) and still the standard reference Australian structural engineers use for universal beams and columns — the same sections covered under Universal Beam (UB) and Universal Column (UC) in this glossary's Lifting & Rigging category.
What Is AISI?
AISI stands for the American Iron and Steel Institute, and in trade use it refers to the numbering system that institute developed for grading carbon and alloy steels — the "1045", "4140" and "4340" style designations seen on steel bar and certificates.
The first two digits identify the alloy family (10 = plain carbon steel, 41 = chromium-molybdenum, 43 = nickel-chromium-molybdenum) and the last two (roughly) indicate carbon content in hundredths of a percent — so SAE/AISI 1045 is a plain carbon steel at about 0.45% carbon. It's an American system in origin, but it's used and cross-referenced constantly in Australian steel supply alongside local AS standards.
Read AIMS's full Steel Grades Comparison Chart →
What Is Alkaline? (Corrosion Context)
Alkaline describes a substance or environment with a pH above 7 — the opposite of acidic — and it matters in a corrosion context because both extremes of the pH scale accelerate metal degradation, just through different chemical pathways. A strongly alkaline (caustic) environment attacks aluminium and zinc coatings in particular, dissolving the passive oxide layer those metals rely on for protection, which is why Zinc Plating and aluminium components are generally unsuitable in caustic washdown or cleaning environments even though they hold up well against plain moisture.
This entry is written to established chemistry and corrosion-science fundamentals — AIMS doesn't have a dedicated article on pH and corrosion specifically, so nothing here is drawn from an AIMS source.
What Is an Allen Key (Allen Wrench / Hex Key)?
An Allen key (hex key, Allen wrench) is an L-shaped hexagonal steel bar used to drive fasteners with a matching internal hexagonal socket — the standard driver for Socket Head Cap Screws and grub screws, among others. "Allen key" is a genericised trademark (from the Allen Manufacturing Company) that's become the dominant Australian term; "hex key" is the strict engineering term, and "Allen wrench" the North American variant.
Beyond the classic L-shaped key, AIMS stocks T-handle versions (more torque, faster rotation, popular for repetitive assembly work), ball-end versions (angled entry up to 25–30° off-axis for obstructed access, but never suitable for final tightening), and hex bits for power tools. Metric and imperial hex keys are not interchangeable — a 5 mm key on a 3/16" socket differs by only 0.237 mm, easily enough to round out and strip the socket under load.
Read AIMS's full Allen Key Guide → for sizing, types and socket-screw compatibility
Shop AIMS's range of hex keys & Allen wrenches →
What Is Allowance (Thread)?
Allowance is a deliberate, specified gap built into a thread fit — an intentional clearance between the external (bolt) and internal (nut) thread, over and above ordinary manufacturing tolerance, to guarantee clearance even at the tightest permitted combination of sizes.
Allowance and Thread Fit are related but distinct: tolerance is the permitted variation *around* a target size, while allowance is the deliberate *offset* applied before tolerance is even added. In practice this matters most on coated or plated threads (galvanised bolts, for example), where the allowance has to be generous enough that the coating thickness itself doesn't cause interference on assembly. *(General engineering fundamentals — no dedicated AIMS article for this term.)*
What Is an Alloy? (Super-Alloy)
An alloy is a metal made by combining a base metal with one or more other elements to improve properties like strength, hardness, corrosion resistance or heat tolerance beyond what the pure metal offers on its own. Alloy Steel, stainless steel, brass and bronze are all alloys built on this principle.
A super-alloy goes further again — these are alloys (usually nickel-, cobalt- or iron-based) engineered to retain strength and resist creep and oxidation at very high temperatures, well beyond where ordinary alloy steels would soften. They're specialised, high-cost materials used in gas turbines, jet engines and extreme high-temperature furnace components — outside AIMS's general industrial supply range but worth knowing the distinction from ordinary alloy steel.
What Is Alloy Steel?
Alloy steel is carbon steel with deliberate additions of other elements — commonly chromium, molybdenum, nickel, manganese or vanadium — to boost strength, hardenability, toughness or corrosion resistance beyond what plain carbon steel can achieve.
The strength difference can be dramatic at the same diameter: AISI 1045 plain carbon steel has a tensile strength around 585 MPa, while AISI 4140 chromium-molybdenum alloy steel reaches roughly 1,020 MPa. That's why alloy steels like 4140 and 4340 are the standard choice for high-stress shafts, gears and fasteners, while plain carbon steel remains the economical default for general fabrication.
Read AIMS's full Steel Grades Comparison Chart →
What Is Allthread?
Allthread (threaded rod, studding — also called Brooker Rod in some parts of the Australian trade; see the dedicated entry below) is a length of steel rod threaded along its entire length rather than just at the ends — cut to whatever length the job needs and paired with nuts and washers on both sides of the material being clamped.
AIMS stocks Allthread in Grade 4.6 (400 MPa mild steel, general construction and MEP hangers, to DIN 976/AS 2451) and Grade 8.8 (800 MPa high-tensile, structural anchors and high-load work, to DIN 976/AS 3501), plus 304 (A2) and 316 (A4) stainless. Standard stock lengths are 1 m and 3 m, with cut-to-length available. Hot-dip galvanised rod needs HDG-matched nuts — standard zinc-plated nuts can bind or strip on the thicker HDG coating. The rule of thumb for thread engagement is that the nut needs at least one nominal diameter's worth of thread contact (an M12 nut needs ≥12 mm of engagement) to develop full strength.
Read AIMS's full Threaded Rod Guide → for grades, finishes and the coupling-nut joining method
Shop AIMS's range of all-thread rod →
What Is Aluminium?
Aluminium is a lightweight, corrosion-resistant, non-magnetic metal roughly a third the density of steel (2,700 kg/m³ vs steel's 7,850 kg/m³), making it the go-to choice wherever weight matters more than absolute strength.
It doesn't rust the way ferrous metals do — instead it forms a thin, self-protecting oxide layer on the surface. Pure aluminium is soft; most industrial and structural aluminium is actually an aluminium alloy (with elements like magnesium, silicon or copper added) to improve strength while keeping the weight and corrosion-resistance advantage.
Read AIMS's full Material Density Chart →
What Is Aluminium Complex Grease?
Aluminium complex grease is a thickener chemistry suited to heavy water exposure, high operating temperatures (rated to around 150°C) and food or pharmaceutical applications where its clean chemistry is an advantage. It sits alongside Lithium Grease, Polyurea Grease, Calcium Sulfonate (Complex) Grease and Clay (Bentone) Grease as one of the five main thickener families AIMS stocks, each suited to a genuinely different combination of temperature, water exposure and load.
Shop AIMS's range of greases →
What Is AMSA? (Australian Maritime Safety Authority)
AMSA is the Australian Government statutory authority responsible for maritime safety — setting and enforcing vessel survey and seaworthiness standards, preventing ship-sourced marine pollution, and coordinating national search-and-rescue for both maritime and aviation incidents.
AMSA's remit sits alongside, rather than inside, the ADG Code above: dangerous goods carried by sea fall under the International Maritime Dangerous Goods (IMDG) Code rather than the ADG Code's road-and-rail framework, and AMSA's Marine Orders set separate requirements for safety and lifting equipment used aboard vessels. For AIMS's customers working in marine, offshore or port-adjacent industrial settings, this means gear specified for onshore lifting and rigging under AS/NZS standards can need an AMSA-compliant equivalent once it's used ship-side.
What Is an Anaerobic Adhesive?
An anaerobic adhesive is a liquid adhesive that stays liquid indefinitely while exposed to air, then cures solid when confined between close-fitting metal surfaces in the absence of oxygen and the presence of metal ions — see Anaerobic Cure for that mechanism in its own right. It's the chemistry behind every Loctite threadlocker, retaining compound and anaerobic thread sealant.
On active metals (steel, iron, copper alloys) cure typically takes 30–60 minutes to a working strength, with full strength reached over 24 hours. Passive metals — stainless steel, zinc plate, chrome, anodised aluminium and black oxide — have an oxide layer that suppresses the metal-ion release the cure needs, so an activator (Loctite 7649 or 7471) should be applied first; with activator, full cure is still around 24 hours, but without it, cure stretches to 48–72 hours and the finished bond is weaker. Threadlocker Colour Grades (Purple/Blue/Red/Green), Wicking Grade threadlocker and Retaining Compound are all specific applications of this same anaerobic chemistry.
Read AIMS's full Industrial Adhesive Types Guide and Thread Lock & Seal Guide →
Shop AIMS's range of Loctite adhesives & thread sealants →
What Is Anaerobic Cure?
Anaerobic cure is a cure mechanism triggered by the absence of oxygen combined with contact against a metal surface — the mechanism behind every Anaerobic Adhesive: threadlockers, Retaining Compound and anaerobic Thread Sealant. It's the opposite trigger from Moisture Cure, which needs air exposure to work at all.
Getting this backwards explains most cure failures in the field: an anaerobic product left exposed to air, or applied to a non-metallic or passive-metal surface without a primer, won't cure properly.
Read AIMS's full Industrial Adhesive Types Guide →
What Is an Anaerobic Gasket Maker?
Anaerobic gasket maker (sometimes called a "gasket eliminator" — Loctite 515 for steel and iron flanges, gap-filling to 0.25 mm, or 518 for aluminium flanges, gap-filling to 0.5 mm with a faster cure) cures rigid, in the absence of air and in the presence of metal ions, and doesn't bond the two surfaces together — which makes disassembly easier and suits precision-machined flanges (pumps, hydraulics, compressors) where the joint needs to stay flat with no deflection.
That's a genuinely different cure mechanism and finished result from RTV silicone, which cures flexible and bonds the casing faces together — see that entry for the practical comparison and why RTV, not anaerobic gasket maker, is the standard choice for cast engine surfaces and general maintenance sealing.
Read AIMS's full RTV Silicone & Gasket Maker Guide and Thread Lock & Seal Guide →
Shop AIMS's range of gasket sealants →
What Is Angle Controlled Tightening?
Angle controlled tightening (also called torque-angle or turn-of-nut tightening) is a bolting method that measures the *rotation* of the fastener past an initial "snug" torque, rather than relying on torque value alone, to control final clamp force.
The method exists because torque alone is a poor proxy for actual bolt tension once friction becomes inconsistent (rusty, dirty, differently-lubricated threads all skew a torque reading at the same clamp load) — measuring the additional angle of rotation after snug-tight is far less sensitive to friction variation and gives a more repeatable preload. It's the standard method specified for structural steelwork bolting to AS/NZS 1252.1 — High Strength Bolts (structural), and is commonly paired with a DTI Washer (Direct Tension Indicating) as an independent cross-check on the same joint.
Read AIMS's full Structural Bolt Tensioning to AS 4100 Guide → for the part-turn tensioning procedure and its AS/NZS 5131 restrictions
What Is an Angle Plate?
An angle plate is a precision-machined workholding fixture with two faces set at an exact right angle to each other, used to hold a workpiece securely at 90° for marking out, drilling or machining a face that can't be clamped flat on its own.
A workpiece is bolted or clamped to the vertical face, and the angle plate's precisely square base then sits flat on a surface plate, machine table or drill press bed — giving an accurately square reference the workpiece itself may not otherwise offer, especially on an irregularly shaped casting or bracket.
What Is an Angular Contact Ball Bearing?
An angular contact ball bearing has its rolling elements set at a defined contact angle through the bearing — typically 15°, 25° or 40° — which lets a single row carry combined radial and axial load rather than radial load alone. Because it only reacts thrust in one direction, it's mounted in matched pairs (see Bearing Mounting Arrangement) wherever thrust can act both ways, and its geometry suits high-speed applications well.
Read AIMS's full Rolling Bearings: Types, Selection, Fitting & Failure Guide →
Shop AIMS's range of angular contact bearings →
What Is an Ankascrew®? (Ramset Trademark — Masonry Screw)
Ankascrew® is Ramset's trademarked masonry screw — a self-tapping fastener that's driven directly into a pre-drilled hole and cuts its own thread into the concrete or masonry as it turns, with no expansion mechanism at all.
That "no expansion" mechanism is the genuine, meaningful difference from Wedge Anchor-family products like Dynabolt® and Trubolt® above: because it doesn't impose radial bursting stress on the surrounding material, a masonry screw can be installed closer to an edge or to another fixing than an equivalent-sized expansion anchor allows under Edge Distance rules, and it's fully removable — unwinding it leaves a clean, empty hole with no protruding metal to grind off, unlike a set expansion anchor. AIMS's own concrete anchor guide notes Hobson's Xbolt as its direct in-range equivalent for this masonry-screw category.
Read AIMS's full Concrete Anchor Guide → for AIMS-stocked masonry screw equivalents
Shop AIMS's range of masonry & concrete anchors →
What Is Annealing?
Annealing is a heat-treatment process where steel is heated to a set temperature and then cooled slowly (usually in the furnace or in still air) to soften it, relieve internal stress and improve machinability or ductility before further work.
It's typically used to undo the hardening effects of prior cold working or welding, making the material easier to machine, bend or draw without cracking. Annealing is the opposite objective to Quenching / Tempering / Normalizing, which are used to harden or strengthen steel rather than soften it.
What Is an Annular Cutter?
An annular cutter is a hollow, ring-shaped cutting tool that removes material only around the circumference of a hole, leaving a solid plug (the "slug") at the centre — fundamentally different from a twist drill, which converts the entire hole volume into chips. That difference is what makes it fast: cutting only an annular ring rather than the full hole volume lets an annular cutter drill a clean, accurate hole in steel plate up to eight times faster than an equivalent twist drill. The industry-standard 3/4" Weldon shank (19.05mm, with two flat-machined faces 180° apart) locks into a Magnetic Drill's quick-change chuck, and a spring-loaded pilot pin runs down the cutter's hollow centre to centre the cut initially, then automatically ejects the slug once the cutter breaks through. Workshop coverage typically spans 12mm to 100mm+ diameter (50mm is the standard workshop default), with depth-of-cut ranging from 25mm for light work to 110mm for heavy structural jobs. See Core Drill (Core Bit) below for the same underlying principle under its more generic name.
Read AIMS's full Annular Cutter Guide → for Weldon shank sizing and selection
Shop AIMS's range of annular cutters & sets →
What Is an Anode / Cathode (Corrosion Context)?
In a corrosion cell, the anode is the metal surface that actually corrodes — it gives up electrons and dissolves — while the cathode is the surface that's protected, receiving those electrons without losing material itself. Every instance of Corrosion, Galvanic in this glossary depends on this pairing: connect two dissimilar metals in the presence of an electrolyte (moisture, salt spray) and the less noble one becomes the anode and corrodes preferentially, protecting the more noble one.
This is also the operating principle behind sacrificial protection: a Zinc Plating coating is deliberately made the anode relative to the steel underneath, so the zinc corrodes first and the steel is protected even where the coating is scratched.
This entry is written to established corrosion-science fundamentals rather than an AIMS source.
What Is ANSI? (American National Standards Institute)
ANSI is the private, non-profit organisation that oversees the development of voluntary consensus standards for products, services, processes and systems across the United States, and is the official US member body to ISO.
ANSI itself rarely writes standards directly — it accredits and coordinates other US standards-developing bodies, including ASME and ASTM (both covered separately in this glossary), and applies the "ANSI-approved" designation once a standard has been through its due-process and consensus requirements. In Australian industrial trade, ANSI shows up constantly as a numbering prefix on product specs that originated in the US market: ANSI Roller Chain Numbering, already covered in this glossary's Belts & Drives category, is the example AIMS customers hit most often, and ANSI-numbered flange dimensions (ANSI/ASME B16.5) turn up throughout pipe fitting and flange specification too.
What Is ANSI Roller Chain Numbering?
ANSI is one of the two competing roller chain sizing systems used across Australian industrial supply — the other being ISO/BS Roller Chain Numbering — and despite both encoding pitch directly in the part number, they are not interchangeable: a chain's roller diameter and plate width differ between the two systems even at a matching nominal pitch.
Under ANSI, the leading digits give the pitch in eighths of an inch — chain #40 has a 4/8" (½", 12.7 mm) pitch, #80 has an 8/8" (1", 25.4 mm) pitch — with the final digit signalling roller width (0 standard, 1 lightweight, 5 rollerless) and a -2 or -3 suffix denoting Duplex Roller Chain or Triplex Roller Chain. Ordering by pitch alone, without checking which numbering system a supplier or an old sprocket is using, is a genuine and common mis-order risk.
Read AIMS's full Roller Chain Guide →
Shop AIMS's range of chain & sprockets →
What Is the ANSI/CAMI Grit System?
The ANSI/CAMI grit system is the US grading standard for coated abrasives like Sandpaper, written as a plain grit number (80-grit, 120-grit and so on). It runs alongside the FEPA P-Grade system rather than replacing it, and the two don't always describe an identical particle size at the same nominal number — an ANSI/CAMI 120-grit disc and a European P120 disc from a different supplier can cut noticeably differently. It's worth checking which system a product is graded to before assuming two discs from different brands are directly interchangeable.
What Is Anti-Seize Compound?
Anti-seize compound is a high-temperature assembly lubricant that stops threaded fasteners and mating surfaces from seizing, galling or corroding together over time. It works by suspending metallic or mineral particles — copper, nickel, aluminium, Moly Grease's molybdenum disulfide, or graphite — in a grease carrier, which forms a sacrificial barrier between the two surfaces rather than relying on the base grease alone.
Type is matched to temperature and material: copper-based handles up to roughly 1,100°C (steel-on-steel, exhaust fittings), nickel-based to around 1,300°C (stainless steel, marine and petrochemical environments), aluminium-based to about 650°C for general use, and moly-based to around 450°C for high-load, slow-speed assemblies. One point AIMS's own guide is direct about: because anti-seize lowers the friction coefficient between threads (roughly 0.13–0.15 versus 0.20 dry), the same torque produces meaningfully higher clamping force — reduce the specified torque by 20–25% when applying anti-seize to a fastener torqued to a dry or lightly lubricated spec, rather than applying the unadjusted figure.
Read AIMS's full Anti-Seize Compound Guide: Types, Uses & Torque Reference →
Shop AIMS's range of anti-seize compounds →
What Is an Anvil (Nutsert Tool)?
In a rivet nut tool, the anvil is the fixed nose piece the mandrel pulls the rivet nut body against — it's what the nutsert's flange or shoulder seats on as the mandrel draws the body up and collapses it into a clamping bulge on the blind side of the panel.
Selecting the correct anvil (matched to the specific rivet nut's thread size and body style) matters as much as selecting the correct mandrel: a mismatched anvil either fails to seat the flange properly or crushes it, and — combined with an incorrectly calibrated depth stop — is one of the more common causes of a rivet nut that spins in the hole once a screw is threaded in. See Nutsert and Mandrel below for the rest of the installation mechanism.
Read AIMS's full Rivet Nut Guide → for tool setup and depth-stop calibration
Shop AIMS's range of rivet nuts & nutserts →
What Is Aramid?
Aramid is the generic name for a family of heat-resistant, high-strength synthetic aromatic polyamide fibres — it's the material category, not a brand. Kevlar® (para-aramid) and Nomex (meta-aramid) are DuPont's trademarked brand names for two specific, chemically different types of aramid fibre, each suited to a different job.
In everyday trade conversation "aramid" and "Kevlar®" often get used interchangeably, but they're not strictly the same thing — Kevlar® is one specific aramid product, not the whole category. Aramid-family fibres show up most commonly in AIMS's range in cut-resistant work gloves, and in the aramid tensile cord inside a Predator Belt, where the fibre's high strength-to-weight ratio and fatigue resistance are put to work handling shock loads rather than cut protection.
Read AIMS's full Work Glove Types guide →
What Is Arc Eye? (Photokeratitis)
Arc eye (photokeratitis) is a UV-radiation burn to the cornea caused by an unshielded welding arc — it can occur in under a minute of exposure, and it's the core hazard behind both auto-darkening welding helmet requirements and the bystander screens used to protect anyone working nearby who isn't wearing welding-rated eye protection themselves.
Unlike a mechanical eye injury, arc eye typically doesn't cause pain until several hours after exposure, once the damage has already been done — which is exactly why relying on discomfort as a warning sign doesn't work, and why welding curtains and screens matter as much for bystanders as helmet filters do for the welder.
Read AIMS's full Welding Helmet Guide →
Shop AIMS's range of welding safety equipment →
What Is AS 1319? (Safety Signs)
AS 1319 is the Australian Standard for safety signs, defining seven sign categories by colour, shape and purpose: danger (red, for hazards where death or serious injury is the likely outcome), prohibition (red circle with diagonal slash, for actions that must not be taken), mandatory (solid blue, for actions that must be done — typically PPE requirements), warning (yellow triangle, for a real but not immediately fatal hazard), emergency/safe condition (green, for exits, first aid and assembly points), fire equipment (red and white) and hazchem/dangerous goods (diamond-shaped, per the ADG Code).
Colour is the fastest layer of communication under the standard — blue signals a mandatory action, red signals prohibition or immediate danger, yellow signals a hazard requiring caution, and green signals a safe direction or condition. One placement principle worth knowing: mandatory PPE signs belong at the approach to a hazard area, not at the hazard itself, giving workers 3–5 metres of visibility to actually put PPE on before entering the zone.
Read AIMS's full Safety Signs Guide →
Shop AIMS's range of Brady labels, signs & lockout equipment →
What Is AS 1345? (Pipe Identification/Marking)
AS 1345 is the Australian Standard for the identification of the contents of pipes, conduits and ducts — setting the colour-coding and labelling system that lets a technician identify what's flowing through a pipe (water, gas, a specific chemical, compressed air) without tracing it back to source.
Correct pipe identification under AS 1345 matters for exactly the situations where getting it wrong is dangerous: isolating the correct line during LOTO, confirming a line is genuinely depressurised before working on a Check Valve or Gate Valve, or simply knowing which of several parallel pipes actually carries the hazardous chemical rather than the harmless one.
Shop AIMS's range of identification products (AS 1345 & AS 1319) →
What Do AS 1418.1 & AS 1418.2 Cover?
AS 1418.1 and AS 1418.2 are the Australian standards for cranes, hoists and winches — AS 1418.1 sets the general design requirements that apply across the whole AS 1418 series, and AS 1418.2 covers serial (production-line) hoists and winches specifically, as distinct from purpose-built cranes. Between them they're the reference point for anything AIMS supplies into crane, hoist or winch applications — chain blocks, lever hoists, come-alongs and jib cranes all sit downstream of this standard, even where the individual product also carries its own component-level spec.
What Is AS 1428.1? (Accessibility)
AS 1428.1 — Design for access and mobility, Part 1: General requirements for access — New building work — is the Australian Standard setting the mandatory accessibility requirements for new public buildings and refurbishments, covering ramp gradients, doorway widths, stair and landing dimensions, and tactile ground surface indicators.
For AIMS's own market, the standard's stair nosing requirements are the most directly relevant: AS 1428.1 requires a continuous luminance-contrast strip (typically 50–75 mm wide, positioned no more than 15 mm from the front edge of the tread) with at least 30% contrast against the surrounding surface, working alongside the slip-resistance P-ratings set under AS 4586 — already covered in this glossary's Safety & PPE category — as the two standards that together drive compliant anti-slip stair nosing selection.
Read AIMS's full Anti-Slip Guide →
Shop AIMS's range of anti-slip safety solutions →
What Is AS 1444? (Wrought Steel Classification)
AS 1444 is the Australian Standard that classifies wrought (rolled or forged) alloy and carbon steels, providing the local Australian numbering and composition system that runs alongside the American AISI/SAE system and European EN system for the same steel families.
It's the standard most directly relevant to sourcing steel bar and plate in Australia against a local specification, and it's the reason a cross-reference between AS, AISI/SAE and EN grade numbers is useful when comparing steel supplied under different naming conventions.
Read AIMS's full Steel Grades Comparison Chart →
What Is AS 1668.2? (Ventilation of Buildings)
AS 1668.2 is the Australian Standard — current edition AS 1668.2:2024, *The use of ventilation and air-conditioning in buildings, Part 2: Mechanical ventilation in buildings* — that sets the minimum outdoor air and mechanical ventilation rates a building's ventilation or HVAC system has to deliver. It's called up directly by the National Construction Code, most commonly cited at a baseline of 10 L/s of fresh air per occupant, rising to 15 L/s once a workshop's temperature exceeds 27°C.
Worth flagging on naming: the standard is often written "AS/NZS 1668.2" in trade material, but the current 2024 edition is published by Standards Australia alone rather than jointly with New Zealand — "AS 1668.2" is the correct current designation, unlike genuinely joint standards elsewhere in the AS/NZS family. In practice, AS 1668.2 governs the airflow a building must achieve, not which specific piece of equipment achieves it — sizing an Indirect-Fired Diesel Heater, an HVLS Fan or a workshop extraction system to actually meet those CFM targets for a given space is a separate design step, best confirmed with a mechanical services engineer for anything beyond a straightforward retrofit.
Read AIMS's full Workshop Ventilation & Fume Extraction Guide →
What Is AS 1674.1? (Welding Safety — Hot Work / Fire Precautions)
AS 1674.1-1997 — *Safety in welding and allied processes, Part 1: Fire precautions* — is the Australian Standard governing fire and explosion prevention during hot work: welding, cutting, heating and grinding across manufacturing, construction, maintenance and demolition, wherever flammable or combustible material could be present. It sets a 15-metre exclusion zone around the hot work point in which every flammable liquid, vapour, gas, combustible material and dust source has to be identified and controlled — a wider radius than most tradespeople expect.
The standard mandates a documented hot work permit (valid for a maximum of eight hours, with gas testing confirming less than 5% of the lower explosive limit before work starts), continuous fire-watching during the job and for at least 30 minutes after the arc stops, and physical screening of the work area — using a Welding Blanket, Welding Curtain or Welding Screen as appropriate — to contain sparks and protect bystanders and nearby combustibles. Note that AS 1674.1 covers fire risk specifically; it doesn't address electric shock, fume exposure or PPE requirements, which sit under separate standards.
Read AIMS's full Welding Blankets & Curtains Guide (AS 1674.1 Hot Work) →
What Is AS 1940? (Flammable & Combustible Liquids Storage)
AS 1940 is the Australian Standard governing the storage and handling of flammable and combustible liquids, setting requirements for tank design, bunding, separation distances and dispensing safety that apply well beyond just fuel depots — diesel and chemical storage on general industrial sites falls under it too.
The core bunding rule is straightforward: a bund must contain at least 110% of the tank's capacity and be impermeable to the stored liquid, though self-bunded (double-wall) tanks satisfy this without separate civil works. Storage tanks must be purpose-built for the job — repurposed water tanks or IBC containers aren't compliant for bulk fuel storage, regardless of how sturdy they look. The standard also classifies liquids by hazard: diesel is a Class C2 combustible liquid with a minimum flash point of 61.5°C, materially safer to store than a Class 3 flammable liquid like petrol, which is reflected in the separation distances and precautions each class requires.
Read AIMS's full Diesel Fuel Storage Guide →
Shop AIMS's range of containers & funnels →
What Is AS 2076?
AS 2076 is the Australian standard for wire rope grips (U-bolt clips) used in non-lifting termination applications — not, despite the name similarity, a standard for wire rope itself. It sets out the grip design and the correct number and spacing of grips for a given rope diameter. See Wire Rope Grip (U-Bolt Clip) below for the practical "3 grips, 6 rope diameters apart" rule AIMS follows.
What Is AS 2129? (Flanges)
AS 2129 is the Australian Standard covering steel flange dimensions and pressure ratings — the standard behind the Table C, D and E pressure classes that Australian water and industrial flanges are specified against, distinct from the American ANSI class system.
Table D and Table E flanges are not interchangeable even at the same nominal size, since their bolt circles and pressure ratings differ — a Table D flange simply will not bolt up to a Table E flange of the same size, which makes checking the actual table designation, not just the pipe size, essential before ordering a mating flange or gasket. See Flange for the component itself.
Shop AIMS's range of pipe flanges and flanges & flanged fittings →
What Is AS 2321?
AS 2321 is the Australian standard for short-link chain used for lifting purposes — the calibrated, close-tolerance chain grade that goes into chain blocks, lever hoists and chain slings, as distinct from the longer-link chain used for general-purpose towing or securing. It's a companion standard to AS 3775.1 & AS 3775.2 (which cover the finished chain sling assembly) and to DIN 766 (the equivalent European short-link chain spec AIMS also sources against).
What Do AS 3775.1 & AS 3775.2 Cover?
AS 3775.1 and AS 3775.2 are the Australian standards for alloy steel chain slings — AS 3775.1 is the product specification (design, materials, proof-testing, WLL marking) for Grade 80 and Grade 100 chain, and AS 3775.2 covers care, use, inspection intervals and rejection criteria once the sling is in service. Every Chain Sling AIMS sells is manufactured and tested to this pair, and a sling's WLL tag should always reference it.
What Is AS 4041? (Pressure Piping)
AS 4041 is the Australian Standard for pressure piping — covering the design, materials, fabrication, inspection and testing requirements for pipework carrying fluids under pressure across industrial, mining and process applications.
It sits alongside AS 1210 (which covers pressure vessels specifically) as one of the two foundational Australian pressure-equipment standards, and it's frequently the standard referenced when a valve, fitting or flange's Australian pressure rating and pipework compliance is being verified for an industrial (as distinct from purely domestic water) installation.
What Is AS 4100? (Steel Structures)
AS 4100 is the Australian Standard for the design of steel structures — it sets out the engineering rules for how structural steel members, connections and welds must be designed and detailed for buildings and other structures in Australia.
It's a structural design and engineering code rather than a product specification, so it doesn't directly determine which fastener or material grade to buy off the shelf — but it's frequently referenced alongside bolt and structural connection specifications in construction and engineering documentation, which is why it shows up regularly in Australian steel-structure conversations and tender documents.
Read AIMS's full Structural Bolt Tensioning to AS 4100 Guide → for how AS 4100 connects to the AS/NZS 5131 bolt categories, tensioning methods and washer selection actually specified on the tools
What Is AS 4130? (Polyethylene Pipe)
AS 4130 is the Australian Standard covering polyethylene (PE) pressure pipe for gas, water and industrial applications — setting the pressure ratings, dimensions and material requirements for PE pipe used in buried and above-ground service where a metal or PVC pipe might otherwise be specified.
PE pipe under this standard is typically joined by butt-welding or electrofusion rather than threaded or flanged connections, which is a genuinely different installation skill set and toolset from the threaded and flanged fittings covered elsewhere in this category.
What Is AS 4267? (Gas Regulator Standard — Type 10 Inlet)
AS 4267-1995 — *Pressure regulators for use with industrial compressed gas cylinders* — is the Australian Standard governing the design, manufacture and performance of gas regulators used across welding, cutting and industrial gas supply, covering inlet fitting types, outlet thread standards, pressure ratings, low-cylinder-pressure flow performance and safety features like relief valves and rupture discs.
The standard's inlet-type system is what physically prevents a regulator being connected to the wrong gas cylinder — a genuine safety feature, not just a compatibility convenience. Type 10 is the standard Australian inlet for argon, MIG shielding-gas blends, helium and low-pressure nitrogen, and is by far the most common fitting on an Australian welding bench. Other gases get deliberately different, incompatible fittings: Type 10.5 for oxygen, Type 20 (left-hand thread, matching acetylene's own reversed convention) for acetylene, Type 30 for pure CO₂, and Type 21 for LPG. Reputable Australian regulator brands state AS 4267 compliance directly on the product — worth checking for, since it confirms the inlet, pressure rating and safety relief features have actually been tested to the standard rather than just assumed.
Read AIMS's full Welding Gas Regulator Guide →
Shop AIMS's Bossweld LPG regulators →
What Is AS 4586? (Slip Resistance Classification)
AS 4586 is the Australian Standard that classifies floor and walkway surfaces for slip resistance using pendulum testing, on a scale from P0 (negligible resistance, unsuitable for safety-critical areas) up to P5 (very high resistance, for external or industrial zones where water or other contaminants are routinely present).
Practical application rules under the standard: internal commercial stairs need a P3 minimum, external stairs and ramps need P4 minimum, and industrial or consistently wet environments should specify P5. Genuine compliance means the product itself is supplied with a test certificate confirming its P-rating — not a marketing claim of "anti-slip" without a tested, numbered rating behind it.
Read AIMS's full Anti-Slip Guide →
Shop AIMS's range of antislip safety solutions →
What Is AS 4991?
AS 4991 is the current Australian standard for below-hook lifting devices and rigging accessories — it's the standard that defines Working Load Limit (WLL) for items like shackles, eye bolts, slings and hooks, setting out the maximum static load each is rated to carry safely in its rated hitch configuration, along with design factor, proof-testing and marking requirements. It sits alongside AS 1418.1 (which covers the lifting *machine* — see MRC in the WLL entry), and it's also the standard a rigging inspector works to when tagging and certifying loose lifting gear on a routine inspection.
Read AIMS's full SWL, WLL, MBL & MRC guide → for how AS 4991 and AS 1418.1 divide up rigging accessories vs lifting machines
What Is AS 5216 (Anchors in Concrete)?
AS 5216:2018 is the Australian standard governing the design and qualification of post-installed anchors in concrete — wedge, sleeve, drop-in and chemical anchors all fall under it — harmonised with European ETA (European Technical Assessment) frameworks for load-capacity data.
The standard's key distinctions matter directly for anchor selection: anchors in cracked concrete are rated to carry roughly 30% less load than the same anchor in uncracked concrete, and different ETA Options qualify an anchor for different combinations of cracked/uncracked concrete and seismic categories (C1/C2) — AIMS's own guide notes ETA Option 1 as the default for structural retrofit work, since it covers both cracked and uncracked concrete plus seismic categories. Hole cleaning is treated as the single most critical installation variable under the standard: a dusty, poorly-cleaned hole can reduce pull-out strength by 50% or more regardless of how correctly the anchor itself was selected.
Read AIMS's full Concrete Anchor Guide → and Chemical Anchor Guide → for AS 5216 ETA options, cure times and installation procedure
Shop AIMS's range of masonry & concrete anchors →
What Is AS/NZS 1252.1 (High Strength Bolts, Structural)?
AS/NZS 1252.1:2016 is the Australian/New Zealand standard covering high-strength structural bolts, nuts and washers — specifically Grade 8.8 bolting assemblies — used in steel building and bridge construction, and referenced directly by AS 4100 (steel structures) and AS 5100 (bridge design) as the specified bolting standard for structural connections.
AS/NZS 1252.1 is the standard behind several other entries in this category: it's why AS 4100 sets Grade 8.8 as the structural minimum (see Property Class above), why structural washers need to be hardened rather than standard commercial-grade (see Types of Washers), and why Angle Controlled Tightening and the DTI Washer (Direct Tension Indicating) exist as verification methods specifically for this class of bolted joint — see AIMS's full guide to structural bolt tensioning, categories and washer selection under AS 4100 for how it all fits together.
Read AIMS's full Metric Bolt Size Guide → for AS/NZS 1252-referenced structural bolt sizing
What Is AS/NZS 1270? (Hearing Protection / Acoustics)
AS/NZS 1270 is the Australian/New Zealand Standard governing occupational hearing protection, and it's the source of the SLC80 (Sound Level Conversion at the 80th percentile) class rating printed on every compliant Australian Hearing Protection product.
SLC80 classes run from 1 (10–13 dB reduction, light industrial noise up to 90 dB(A)) to 5 (26+ dB reduction, extreme noise up to 110 dB(A) — mining, airports). It's genuinely not interchangeable with the American NRR rating: NRR is derived under different lab conditions and is typically a higher number than SLC80 for an equivalent product, so only SLC80 figures are valid for Australian WHS compliance.
Read AIMS's full Hearing Protection Guide →
Shop AIMS's range of ear protection →
What Is AS/NZS 1337.1? (Eye Protection)
AS/NZS 1337.1 is the Australian/New Zealand Standard for occupational eye and face protection, setting the Impact Class (Safety Glasses) and Optical Class (Safety Glasses) rating systems that every compliant pair of safety glasses in Australia is tested and marked against.
Compliant eyewear carries the standard's marking directly on the lens or frame — checking for that marking, rather than assuming a US-marked import is equivalent, is the practical compliance check most relevant to buyers.
Read AIMS's full Safety Glasses Guide →
Shop AIMS's range of welding safety equipment →
What Is AS/NZS 1715? (Respiratory Protection Selection)
AS/NZS 1715 is the companion standard to AS/NZS 1716 — Respiratory Protective Devices: where 1716 sets what a respirator must achieve as a manufactured device, 1715 covers how a workplace actually selects, uses and maintains respiratory protection for a specific hazard and exposure level.
That includes choosing the correct Respirator Filter Class, deciding whether a disposable, reusable or powered device (PAPR) is appropriate, and running the required Fit Testing program — the practical, workplace-facing half of respiratory protection compliance.
Read AIMS's full Respirator & Dust Mask Guide →
What Is AS/NZS 1716? (Respiratory Protective Devices)
AS/NZS 1716 is the Australian/New Zealand Standard that sets the performance, testing and classification requirements for respiratory protective devices — it's the standard behind the P1/P2/P3 Respirator Filter Class system used across every respirator sold for Australian workplace use.
It covers the device itself: filter efficiency, breathing resistance, facepiece design and materials. Selecting the right device for a given hazard and workplace is a separate step, covered by AS/NZS 1715 — Respiratory Protection Selection rather than AS/NZS 1716 itself.
Read AIMS's full Respirator & Dust Mask Guide →
Shop AIMS's range of respiratory protection →
What Is AS/NZS 1801? (Occupational Protective Helmets)
AS/NZS 1801 is the Australian/New Zealand Standard for occupational protective helmets — it's the standard behind every certified Hard Hat (Safety Helmet) type and electrical class sold for Australian workplace use, most recently updated in 2024 to add a fourth helmet type with multi-directional impact protection.
Read AIMS's full Hard Hat Guide →
Shop AIMS's range of hard hats →
What Is AS/NZS 1891.4? (Fall Arrest Systems)
AS/NZS 1891.4 is the Australian/New Zealand Standard covering the selection, safe use and maintenance of industrial fall-arrest systems — the practical, workplace-facing standard that governs how a Full Body Harness and Inertia Reel (Self-Retracting Lanyard) are actually chosen and used together, as distinct from AS/NZS 1891.1 and .3, which cover how the equipment itself is manufactured.
Key hard limits under the standard: maximum free-fall distance is 2 metres, anchor points must support a minimum static load of 15 kN per worker, and harnesses have a non-negotiable 10-year service life from the date of manufacture regardless of inspection result. The standard also draws a firm line between fall arrest, fall restraint and work positioning — three genuinely different systems that are often confused, with using restraint equipment in an arrest scenario being one of the most consequential mistakes made in Australian fall protection.
Read AIMS's full Safety Harness Guide →
Shop AIMS's range of height safety equipment →
What Is AS/NZS 2161.4? (Protective Gloves)
AS/NZS 2161.4 is the Australian/New Zealand Standard covering protective gloves against mechanical risks — the local equivalent to EN 388 — Cut-Resistant Gloves — and, for welding-specific gloves, the standard that requires marking against six thermal performance properties: flame spread, contact heat, convective heat, radiant heat, and resistance to molten metal splashes and small splashes.
Most Australian welding gloves carry both the AS/NZS 2161.4 marking and its European equivalent, EN 407 — Heat-Resistant Gloves, side by side.
Read AIMS's full Welding Gloves Guide →
Shop AIMS's range of hand protection →
What Is AS/NZS 2210.3? (Safety Footwear)
AS/NZS 2210.3 is the Australian/New Zealand Standard for occupational protective footwear, setting the impact (200 J) and compression (15 kN) thresholds that every certified Safety Footwear toecap — steel or composite — must meet, plus the separate EH (Electrical Hazard) rating for boots used around live circuits.
Read AIMS's full Steel Cap Boots Guide →
Shop AIMS's range of safety footwear →
What Is AS/NZS 3000?
AS/NZS 3000 — the "Wiring Rules" — is the core Australian and New Zealand standard for the design, construction and testing of electrical installations, covering everything from cable sizing and circuit protection to switchboard layout and earthing. It's the standard an electrician's work is ultimately judged against, and it's the reference point behind several of the specific requirements mentioned elsewhere in this glossary — including where an RCD is mandatory rather than optional.
What Is AS/NZS 4602.1? (High-Visibility Clothing)
AS/NZS 4602.1 is the Australian/New Zealand Standard for high-visibility safety garments, setting the Hi-Vis Classification (Class D/Class N) system and the retro-reflective tape requirements behind every compliant hi-vis vest, shirt or set of pants sold for Australian workplace and roadside use.
Read AIMS's full Hi-Vis Vest Guide →
Shop AIMS's range of hi-vis workwear →
What Is AS/NZS 4836?
AS/NZS 4836 covers safe working on or near low-voltage and extra-low-voltage electrical installations and equipment — the practical safe-work procedures (isolation, testing for dead, permits) that sit alongside AS/NZS 3000's design and construction requirements. Where AS/NZS 3000 governs how an installation is built, AS/NZS 4836 governs how people work on it safely once it exists.
What Is ASME? (American Society of Mechanical Engineers)
ASME is the US professional engineering association that develops and publishes technical codes and standards for mechanical engineering, best known industrially for the ASME Boiler and Pressure Vessel Code and for widely-used product-dimension standards like ASME B16.5 (pipe flanges) and ASME Y14.5 (geometric dimensioning and tolerancing).
ASME's focus is mechanical design and engineering practice, which distinguishes it from ASTM, the US body that specifies the materials and testing methods those designs are built to rather than the designs themselves — the two are frequently cited together on the same engineering drawing for exactly that reason. AIMS's own Pipe Flange Guide covers ASME B16.5 flange dimensions directly, one of the more common places Australian trade encounters an ASME standard by number without necessarily knowing the body behind it.
What Is Assembly?
Assembly is the process of fitting together individual components, parts or sub-assemblies into a finished product or system — the manufacturing step that turns a bill of materials into something that actually works.
Assembly ranges from simple manual work (bolting a bracket together with a spanner) through to complex, multi-stage production-line processes involving jigs, fixtures, torque-controlled fastening and quality checks at each stage. It's a core concept behind MRO (keeping assembled equipment running), OEM (who designs and originally assembles a product) and SKD/CKD (equipment shipped as parts specifically to be assembled locally rather than as a finished unit).
What Is ASTM? (American Society for Testing and Materials)
ASTM International — renamed from the American Society for Testing and Materials in 2001, though the original name is still how most people know it — develops and publishes voluntary consensus standards specifying materials, products, systems and testing methods, spanning everything from structural steel grades to fastener material specifications.
ASTM's core job is defining what a material is and how to test it, which distinguishes it from ASME, the US body whose standards cover mechanical design and engineering practice instead — a steel plate's ASTM grade and the ASME code governing the pressure vessel built from it are two separate standards doing two separate jobs, and both commonly appear on the same specification sheet. ASTM-numbered material grades turn up regularly in Australian fastener and structural steel specs alongside their Australian Standard equivalents.
What Is ATM (Aggregate Trailer Mass)?
ATM is the maximum permitted mass of a trailer and its load when the trailer is *not* coupled to a towing vehicle — in other words, the full weight the trailer's own axles and any towball/kingpin load would carry on their own, as set by the trailer manufacturer. It's distinct from GTM, which only counts the mass actually transmitted to the trailer's own axles once it's hooked up and towing, since some of the load is then carried by the tow vehicle instead.
What Is an Auger Bit?
An auger bit is a long, spiral-fluted drill bit for boring deep, clean holes in timber, with a screw-point tip that pulls the bit through the material as it turns rather than needing the operator to force it forward. The long flutes clear a high volume of wood chips efficiently over a deep hole — the reason auger bits are the standard choice for deep timber and formwork boring where a standard twist bit would clog and overheat. See Forstner Bit below for the woodworking bit that trades an auger's speed for a cleaner, flat-bottomed result.
Shop AIMS's range of auger drill bit sets →
What Is Austenizing? (Austenite)
Austenite is a high-temperature crystal structure (phase) of iron and steel that only exists above a specific transformation temperature (around 727°C for plain carbon steel) — it's the structure steel must be heated into before most hardening heat treatments can work.
Austenizing is the act of heating steel into that austenite phase as the first step of hardening: from austenite, rapid cooling (Quenching / Tempering / Normalizing) transforms the structure into hard Martensite, while slow cooling produces softer structures. This is heat-treatment-shop terminology rather than something a buyer needs day to day, but it explains why heat-treated parts are always heated to a specific, controlled temperature rather than "just made hot."
What Is an Automatic Transfer Switch (ATS)?
An Automatic Transfer Switch (ATS) is a Changeover Switch that operates without manual intervention, automatically switching a switchboard from mains to backup generator supply — typically within 10 to 30 seconds of an outage being detected — and back again once mains power returns. Like a manual changeover switch, its core job is preventing Backfeeding, but automating that isolation step is what makes an ATS suited to unattended or safety-critical backup power setups where someone flipping a manual switch in time can't be relied on.
What Are Automotive Blade Fuses (ATO/ATC, Mini, Micro2/3, Maxi)?
Automotive blade fuses protect 12V/24V vehicle and equipment circuits, and come in several physical sizes that are not all interchangeable: Standard blade (ATO/ATC) is 19mm wide and covers 1–40A; Mini (ATM/APM) is 11mm wide, 2–30A; Micro2 (ATR) is 9.1mm wide, 5–30A, common in newer Japanese and Korean vehicles and EVs; Micro3 is a compact 3-terminal version for modern ECM circuits, 5–15A; and Maxi/Mega (APX) is a larger 29mm, 20–100A+ fuse for higher-current circuits. All sizes broadly share the same ISO 8820 colour code by amperage (10A red, 15A blue, 20A yellow, 25A clear, 30A green, 40A orange) — but the same colour means a different rating on a different size fuse (a Maxi 50A and a Standard 10A are both red), so always check the physical size before reading the colour.
What Is AWG (American Wire Gauge)?
AWG (American Wire Gauge) is a wire sizing system, most commonly encountered in the US and in automotive/12V wiring, where a smaller gauge number means a thicker conductor — 10 AWG is thicker and carries more current than 18 AWG. It's a different numbering system to SWG (Standard Wire Gauge) and to metric cross-sectional-area sizing (mm²) used in AU wiring rules, so a gauge number alone isn't enough to confirm equivalence — the actual conductor cross-section should be checked when substituting between systems.
What Is Axial Load / Thrust Load (Bearing)?
Axial load — also called thrust load — is force applied parallel to a bearing's axis, pushing the shaft lengthways rather than sideways. It's the load direction a dedicated Thrust Ball / Thrust Roller Bearing exists purely to carry, and it's why bearings that combine radial and thrust capacity — angular contact and tapered roller types — are mounted in matched, opposed pairs rather than singly: a single one only reacts thrust in one direction.
As a rule of thumb from AIMS's own guide, a standard thrust ball bearing carries very little radial load alongside its axial rating — typically under 5–10% of its axial rating — so side-loading a pure thrust bearing causes rolling-element skidding and accelerated wear rather than simply working less efficiently.
Read AIMS's full Thrust Bearing Guide: Types, Sizes & Selection →
Shop AIMS's range of thrust bearings →
B
What Are B-Double / B-Triple Combinations?
A B-Double is a Prime Mover towing two semi-trailers linked directly to each other by a Turntable (a fifth-wheel-style coupling mounted on the rear of the lead trailer) rather than by a drawbar — the "B" refers to this direct semi-to-semi link, as opposed to an "A-double" using a Converter Dolly. A B-Triple extends the same principle to three linked trailers. Both require specific route approval and higher-level driver accreditation in Australia given their length and mass.
What Is BA (British Association) Thread?
BA (British Association) is a small-diameter British thread standard with its own numbering system, separate from BSW/BSF — sizes are identified by a number where a *larger* number means a *smaller* thread (0BA is the largest in the series, running down through finer sizes from there), the reverse of how metric and most imperial systems number their sizes.
BA threads are found mainly on small precision hardware — instruments, electrical terminals, clocks, older telecommunications and scientific equipment — rather than structural or general engineering fastening, reflecting their origin as a precision-instrument standard rather than a general-purpose one. AIMS's fastener conversion guide lists BA sizes by their equivalent TPI for reference alongside the more common metric and Unified systems.
Read AIMS's full Metric to Imperial Fastener Conversion Chart → for BA size-to-TPI reference
What Is Backfeeding?
Backfeeding is generator power flowing backwards out of a building's switchboard and into the street electricity grid — a serious hazard for utility workers who reasonably assume a de-energised line is safe to work on. It's the specific risk a Changeover Switch or Automatic Transfer Switch (ATS) exists to prevent, by physically isolating the switchboard from the grid before generator power is ever connected, so the two supplies can never be live on the board at the same time.
What Is a Backflow Preventer?
A backflow preventer is a device fitted into a water line to stop water flowing in reverse — back into the clean drinking-water supply — protecting the potable water system from contamination if pressure in a connected line (an irrigation system, a chemical dosing rig, a fire system, a commercial dishwasher) ever drops below mains pressure and reverses the normal flow direction.
Australian backflow prevention devices are governed by AS/NZS 2845 (materials, design and performance requirements), and the device required is matched to the actual hazard rating of what's connected downstream — a simple dual check valve is adequate for a low-hazard connection, while a testable reduced pressure zone (RPZ) device is mandated wherever a genuinely high-hazard cross-connection exists (a chemical dosing system or an unprotected irrigation system are common triggers). Backflow prevention isn't a set-and-forget device: testable assemblies require regular certified testing under most Australian water authorities' requirements, since a backflow preventer that has silently failed gives no visible warning that the protection it's meant to offer is gone. See Check Valve for the simpler, non-testable device family that shares the same one-way-flow principle without carrying formal backflow-hazard certification.
What Is a Backing Pad?
A backing pad is the rubber or rigid fibre disc fitted between a power tool's spindle and a fibre-backed abrasive disc, spreading the retaining nut's clamping force evenly across the disc face and cushioning it against the tool. It's not optional hardware: a fibre Sanding Disc run without a backing pad flexes unevenly under load and cracks, rather than wearing down safely.
What Is Baking (Hydrogen Embrittlement Relief)?
Baking is a controlled heat-treatment step applied after electroplating a steel fastener, to drive out absorbed atomic hydrogen before it can cause delayed brittle cracking — see Hydrogen Embrittlement below for the failure mechanism it's designed to prevent.
Baking has to happen soon after plating (delayed baking is a documented cause of embrittlement relief failing, since some hydrogen-assisted cracking can already be underway before the part ever reaches the oven), typically in the range of roughly 190–220°C held for several hours, with time counted from when the fastener itself — not just the surrounding oven air — reaches temperature. ASTM F519 is the standard test method used to verify a given plating/baking process actually relieves embrittlement risk on a representative sample, rather than simply assuming a given bake schedule works. High-strength fasteners (Grade 10.9 and 12.9, or their imperial equivalents) are the parts this matters most for — their higher hardness makes them significantly more susceptible to hydrogen-assisted cracking than a lower-grade bolt. *(Independent standards source — ASTM F519 and published metal-finishing industry guidance — no dedicated AIMS article for this specialised plating process.)*
What Is a Ball Pein Hammer?
A ball pein hammer has a flat striking face on one side and a rounded "pein" (or "peen") face on the other, purpose-built for metalworking tasks a standard flat-faced hammer isn't suited to — rounding over a rivet head, closing a hand-set rivet, or striking a Centre Punch or cold chisel without the flat face's sharper edge marking the work.
The rounded pein face is also used for peening — work-hardening a metal surface by repeated light striking — a technique distinct from simply driving or striking with the flat face.
Read AIMS's full Hammer Types Guide →
Shop AIMS's range of hammer handles →
What Is a Ball Valve?
A ball valve is a quarter-turn valve that uses a drilled, rotating ball to open or block flow — turning the handle 90° rotates the ball's bore in or out of line with the pipe, giving fast, positive shutoff with very low pressure drop when fully open.
Body construction determines maintenance access: 1-piece bodies are essentially disposable when worn, 2-piece bodies (the most common configuration) need removing from the pipeline to access the seats, and 3-piece bodies let the centre section be removed for in-line seat and seal replacement while the end caps stay bolted to the pipe. Bore geometry is the other major choice — a Full-Bore Valve configuration matches the pipe's internal diameter exactly (allowing pigging, at higher cost), while a reduced-port ball valve is one size smaller through the valve, cheaper but not pigging-compatible. Body material is selected by media: standard brass suits workshop air and irrigation up to about 120°C; DR (dezincification-resistant) brass is mandatory for Australian potable water under AS 5830.1; 316 stainless handles chemical service, marine splash and food/dairy duty; and carbon steel covers oil/gas pipelines and high-pressure steam mains. Seat material sets the actual pressure/temperature envelope and chemical compatibility, from PTFE (universal chemical resistance, -40°C to 200°C) up to PEEK (-40°C to 315°C, for genuinely high-pressure and high-temperature combined duty) — critically, soft-seated valves (PTFE, RPTFE, PEEK or elastomer) achieve bubble-tight ANSI Class VI shutoff, while metal-seated valves only reach Class IV or V, with a small allowable leakage rate. Never throttle a standard ball valve — running it part-open creates a high-velocity jet that erodes the soft seat material within days to weeks; genuine flow-modulation duty calls for a V-port ball valve, a Globe Valve, or another purpose-built Throttling Valve. Actuated ball valves for automation always use trunnion-mounted construction regardless of size, mounted to an ISO 5211 actuator pad, and gas or potable-water service triggers mandatory Australian certification — AS 5601/AS 4617 for LPG and natural gas, AS 5830.1 and WaterMark Certification for drinking water.
Read AIMS's full Ball Valve Guide →
Shop AIMS's range of ball valves →
What Is Barrier Protection (Corrosion)?
Barrier protection is corrosion prevention by simple physical exclusion — a coating, paint film, plating layer or grease film that keeps moisture and oxygen away from the base metal, with no electrochemical mechanism involved. It's the passive counterpart to Cathodic Barrier Protection: a barrier coating only works while it stays intact, and once it's scratched or worn through, the exposed metal underneath corrodes with no further protection from the coating itself — unlike a sacrificial zinc coating, which keeps protecting the steel even through a scratch.
This entry is written to established corrosion-science fundamentals rather than an AIMS source.
What Is Base Oil (Grease/Lubricant Component)?
Base oil is the fluid component of a Grease — mineral or synthetic — that the thickener holds in suspension, and it's what actually does the lubricating; the thickener's job is purely to hold that oil in place rather than to lubricate anything itself. AIMS's own guide gives base oil as 75–95% of a grease's total composition by weight, with its viscosity (not the thickener type) largely determining the grease's load-carrying capacity — which is why two greases with the same thickener chemistry can still perform very differently depending on the base oil viscosity behind them.
Read AIMS's full Grease Selection Guide: Types, NLGI & EP →
What Is a Beam Trolley (Girder Trolley)?
A beam trolley (girder trolley) is a wheeled carriage that runs along the bottom flange of an I-beam or universal beam, letting a chain block, lever hoist or load be moved horizontally along the beam's length. Trolleys are sized by flange width — AIMS's range spans the common AU structural flange widths, and matching the trolley's adjustable jaw width to the actual beam (measured, not assumed from the beam's nominal size) is the single most common fitting mistake on site. A girder clamp does a related but different job — clamping onto the beam as a fixed lifting point rather than running along it.
Read AIMS's full Beam Clamp Guide → for trolley and clamp sizing by flange width
Shop AIMS's range of beam and girder trolleys →
What Is a Bearing?
A bearing is a mechanical component that reduces friction between moving parts and allows smooth, controlled rotation or linear movement. Most bearings do this with a set of Rolling Elements — balls or rollers — running between an inner and outer Race, though a Plain Bushing achieves the same result with a sliding rather than rolling contact.
Bearings are selected around the load direction they need to carry: a Radial Load running perpendicular to the shaft, an Axial Load (thrust) running along it, or a combination of both. Which bearing type suits which load pattern — deep groove, angular contact, tapered roller, spherical roller, needle or thrust — is covered in each of those entries below.
Read AIMS's full Rolling Bearings: Types, Selection, Fitting & Failure Guide →
Shop AIMS's range of bearings and power transmission products →
What Is a Bearing Adaptor Sleeve / Withdrawal Sleeve?
An adaptor sleeve is a tapered steel sleeve that lets a bearing with a tapered bore be mounted onto a plain, straight shaft — with no shaft shoulder needed — by driving the sleeve into the gap between shaft and bore until the correct clearance reduction is reached. A withdrawal sleeve is the same idea used in reverse: it lets that same bearing be drawn back off the shaft for removal, typically with a withdrawal nut and hydraulic assistance on larger sizes.
Both are common on Spherical Roller Bearings and Pillow Block-mounted bearings on continuous shafting, where a shoulder to locate a straight-bore bearing either doesn't exist or would be impractical to machine.
Shop AIMS's range of bearing adaptor sleeves and withdrawal bushings →
What Is a Bearing Designation Code (e.g. 6205-2RS-C3)?
A bearing designation code is the string of numbers and letters stamped on a bearing that specifies its exact type, size and features — for example, 6205 2RS C3: "6" is the bearing type (deep groove ball, single row), "2" is the diameter series, "05" is the bore code (25 mm — bore codes from 04 up are multiplied by 5 to get the bore in millimetres), "2RS" is the Bearing Seal Code, and "C3" is the C3 / C4 Internal Clearance class.
This structure is standardised by ISO 15:2017 for the dimensional part of the code — meaning a 6205 from SKF, NSK, NTN, Koyo, NACHI or FAG all share exactly the same bore, outside diameter and width — but the suffix notation for seals, clearance and cage type isn't standardised between brands, which is exactly what makes cross-referencing a failed bearing to another manufacturer's equivalent a genuine skill rather than a lookup.
Read AIMS's full Bearing Cross Reference Guide: SKF, NSK, NTN, Koyo, NACHI, FAG & More →
Shop AIMS's range of bearings and power transmission products →
What Is a Bearing Mounting Arrangement — Back-to-Back / Face-to-Face / Tandem (DB/DF/DT)?
A bearing mounting arrangement describes how a pair of Angular Contact Ball Bearings or Tapered Roller Bearings is set up on a shaft, since a single one of either type only reacts thrust in one direction. DB (back-to-back) mounts the two bearings with their wide faces outward, giving a wide effective axial spacing well suited to combined heavy loads and moment resistance. DF (face-to-face) mounts them with narrow faces outward, a more compact arrangement suited to moderate combined loads. DT (tandem) mounts both bearings facing the same direction, sharing a heavy one-directional load between them rather than reacting thrust both ways at all.
Read AIMS's full Rolling Bearings: Types, Selection, Fitting & Failure Guide →
What Is a Bearing Press?
A bearing press is a mechanical or hydraulic press used together with a Fitting Sleeve to install or remove small and medium bearings under controlled, even force, rather than relying on hammer blows. It's the correct-method counterpart to the emergency soft-drift approach AIMS's own maintenance guide warns against, and — for removal rather than installation — the counterpart to a dedicated bearing puller on bearings that are seized rather than simply interference-fitted.
AIMS doesn't currently stock a dedicated bearing press line — included here on relevance to the trade, per the coverage principle agreed for this glossary. See Fitting Sleeve above for the actual tooling AIMS does stock that a bearing press is typically used with, and the existing bearing puller range for removal-side tooling.
Read AIMS's full Bearing Maintenance: Inspection, Lubrication & Replacement Guide →
Shop AIMS's range of bearing pullers →
What Is a Bearing Puller?
A bearing puller is a tool that draws a bearing off a shaft or out of a housing without cutting or damaging the shaft, using mechanical or hydraulic force in place of the heat and impact a Bearing Press or Fitting Sleeve relies on for installation. AIMS's own guide splits the family into four types: external pullers, where a central screw pushes against the shaft end while 2-jaw or 3-jaw arms hook behind the bearing's outer race (3-jaw is the workshop standard, distributing load symmetrically); internal pullers, with expanding collets that grip the inner bore where the outer race isn't accessible; blind hole pullers, using a slide hammer against expanding collets for bearings buried in closed-end bores such as pilot bearings or alternator housings; and hydraulic pullers, delivering roughly 10–50 tonnes of controlled force for large bearings (over about 100 mm bore) or badly seized fits.
One safety point worth repeating from AIMS's own guide: never heat the bearing itself to help remove it — thermal expansion of the bearing relative to the shaft only tightens the fit further. Heat the surrounding housing instead, to expand the bore around a stuck bearing.
Read AIMS's full Bearing Puller Guide: External, Internal & Hydraulic →
Shop AIMS's range of bearing pullers →
What Is the Bearing Seal Code? (2RS / ZZ / Open)
The seal code is the part of a Bearing Designation Code that specifies how (or whether) a bearing is sealed. Open means no seal at all — exposed rolling elements, relying entirely on external lubrication and housing seals. ZZ (sometimes 2Z) means metal shields fitted to both sides — non-contact, so lower friction and slightly higher speed capability, but only excluding coarse contamination rather than sealing fully. 2RS means rubber contact seals on both sides — full sealing against dust, water and fine contamination, factory-packed with grease for life, at the cost of higher rolling friction than ZZ or Open.
The same physical seal type carries a different suffix by brand — AIMS's own cross-reference guide notes that FAG uses 2RSR where SKF uses 2RS1 and NSK uses DDU, all describing the same two-sided rubber-sealed bearing.
Read AIMS's full Deep Groove Ball Bearing Guide: 6200/6300, Seals & Brands →
Shop AIMS's range of deep groove bearings →
What Is Bearing Tolerance Class — Shaft (k5/m5/n6) & Housing (H7/J7/K7) Fits?
Bearing tolerance class specifies the ISO tolerance grade for the shaft a bearing's inner ring mounts on, and the housing bore its outer ring sits in — separate from the bearing's own internal C3 / C4 Internal Clearance. For a standard rotating-shaft, stationary-housing arrangement, AIMS's own guide gives k5, m5 or n6 as the typical shaft tolerances (tighter fits like m5 and n6 prevent the ring creeping under load) against H7, J7 or K7 for the housing bore.
This is a genuinely distinct sense of "Class" from the thread-fit, pressure-flange and electrical-insulation classes already tracked in this glossary's disambiguation notes — worth flagging as a fourth sense for that tab rather than folding it into an existing entry. Cross-link with the existing ISO 286 standard entry, which is the tolerance-grade system this class structure is drawn from.
Read AIMS's full Rolling Bearings: Types, Selection, Fitting & Failure Guide →
What Is a Bearing-Type Joint?
A bearing-type joint is a bolted connection designed on the assumption that the bolt itself will be loaded in shear and will physically bear against the sides of the bolt hole under load — as distinct from a Friction Type Joint / Slip-Critical / Snug-tightened / Pretensioned Joint, which is designed to transfer load entirely through friction between the clamped plates, with the bolt never expected to contact the hole wall in normal service.
Bearing-type joints only need to be tightened to a "snug-tight" condition (enough to bring the plies into firm contact, without a specified preload), which makes them faster and cheaper to install than a fully pretensioned friction joint — but they also allow a small amount of initial slip as the bolt takes up clearance in the hole before it starts bearing, which matters for fatigue-sensitive or precisely-aligned structures. Structural designers choose between the two joint types based on whether that small amount of slip is acceptable for the specific connection.
Read AIMS's full Structural Bolt Tensioning to AS 4100 Guide → for the full S/TB/TF category breakdown and snug-tight vs fully tensioned procedure
What Is a Belleville Washer?
A Belleville washer (disc spring, coned-disc spring) is a conical washer that flexes flat under axial load, acting as a stiff, compact spring in applications where a coil spring won't fit or where very high force needs to be developed over a very short deflection.
Belleville washers can be stacked in different configurations — in series (same orientation, nested) to increase total deflection at the same force, or in parallel (alternating orientation) to increase total force capacity at the same deflection — which is the main reason engineers reach for them over a standard Spring washer where genuine spring force, not just vibration resistance, is required. Typical uses include maintaining clamp load across thermal cycling in flanged joints, and providing controlled preload in bearing assemblies. *(General engineering fundamentals — no dedicated AIMS article for this term.)*
Shop AIMS's range of washers →
What Is a Belt? (Power Transmission)
A belt is a flexible loop of rubber, fabric or polymer material that transfers rotational power between two or more pulleys, using either friction (V-belts, flat belts) or positive tooth engagement (synchronous/timing belts) rather than a rigid mechanical link like a chain or gear train.
Belt drives are the default choice for clean, moderate-torque industrial and automotive applications: they run quieter than a Roller Chain Drive, need no lubrication, and tolerate minor misalignment better than a gear train — the trade-off is some inherent slip (except with a synchronous belt) and a lower absolute torque capacity than chain of the same drive size. Choosing between belt types comes down to speed, torque, shock loading and noise tolerance — see V-Belt (Drive Belt), Synchronous (Timing) Belt, Pulley and Sheave for how the pieces fit together.
Read AIMS's full Belt vs Chain Drives Guide →
Shop AIMS's range of industrial drive & conveyor belts →
What Is a Belt Cross-Reference? (Interchange)
A belt cross-reference matches an equivalent belt part number across different brands or belt families — for example A50 = AX50 = SPA1307 — by comparing datum length, profile and top width between the two systems.
It's not always a direct, risk-free one-to-one match: notched and cogged variants of a similar overall size can differ meaningfully in load rating and heat resistance even when the cross-reference chart lists them as equivalent, so a cross-reference is a starting point for finding a substitute belt, not a guarantee that every listed equivalent performs identically in every application.
Read AIMS's full V-Belt Sizing & Identification Guide →
Shop AIMS's range of industrial drive & conveyor belts →
What Is Belt Length Notation? (La/Le/Ld/Lp/Lw/Li)
Belt length notation is the set of standard abbreviations manufacturers use to specify exactly which length measurement a belt's size number refers to, since a belt can genuinely be measured several different ways with different results.
La (outside length) is measured with a relaxed tape around the outside of the belt — quick but inconsistent, since belt tops vary between arched and flat profiles. Li (inside length) uses flat pulleys and a tape on the inside face — also not recommended for specification, due to manufacturer-to-manufacturer variation. Ld (datum/pitch length) is measured at the belt's neutral cord axis and is now the industry standard for accurate specification, replacing the older Lp (pitch length) term, which is still used informally. Le (effective length) is measured about a sheave's effective outside diameter at a specified tension, used for precise drive design calculations. Lw (nominal length) exists in name only — it's a designation reference like "A38" or "3V300," not a measurable dimension at all. Getting these mixed up is the single most common cause of ordering the wrong belt length for a given drive.
Read AIMS's full Belt Length Acronyms Guide →
Shop AIMS's range of industrial drive & conveyor belts →
What Is a Belt Scraper? (Conveyor Cleaner)
A belt scraper — also called a conveyor belt cleaner — is a blade assembly, typically polyurethane or tungsten-tipped, held against the belt at or near the head pulley to remove residual material ("carryback") that would otherwise stick to the belt and drop off further along the return run.
Scrapers are commonly fitted in two stages: a primary scraper mounted directly at the head pulley face, taking the bulk of the material while the belt still has curvature to help lift material off, and a secondary scraper mounted a short distance along the return run to catch what the primary missed. Left uncleaned, carryback builds up on Troughing Idler and return idler rollers, causing exactly the Belt Tracking (Conveyor) problems and premature idler wear those components are meant to avoid — a scraper is as much a protection for the rest of the conveyor as it is belt housekeeping. Blade tension and wear need regular checking, since an over-tightened scraper accelerates Cover Compound (Conveyor Belt) wear on the very belt it's meant to protect.
What Is a Belt Tension Gauge?
A belt tension gauge is a hand tool used to measure and confirm correct Belt Tensioner setting on a drive, most commonly by the deflection method: applying a known force at the belt's midpoint span and reading how far it deflects, then checking that figure against the belt manufacturer's target deflection table for that profile and span.
Two other measurement methods exist alongside a direct deflection gauge: the frequency method, which plucks the belt like a guitar string and reads its resonant frequency to look up target tension in a manufacturer's table, and a mechanical tension tester, which reads installed tension directly and is faster than deflection but less precise than the frequency method. A straight-edge or string-line check across the pulley faces catches only gross alignment errors, so a proper gauge — not tensioning "by feel" — is what a genuinely correct setup relies on.
Read AIMS's full Diagnosing Improper Belt Tension or Misalignment Guide →
Shop the Gates Krikit Belt Tension Gauge →
What Is a Belt Tensioner?
A belt tensioner is a device — usually a spring-loaded or manually adjustable Idler Pulley — that maintains correct belt tension on a drive, compensating for the gradual stretch and bedding-in that every belt undergoes over its service life.
Getting tension right matters in both directions: an under-tensioned belt slips, glazes and squeals on start-up, losing drive efficiency, while an over-tensioned belt stretches its reinforcing cords prematurely and overloads the shaft bearings with excess radial load, causing uniform sidewall wear from the extra groove pressure. New belts also need a specific re-check: they seat into the groove and lose 5–10% of their installation tension in the first 24 hours, so a genuine tensioning job always includes a run-in re-check, not just a single set-and-forget adjustment. See Belt Tension Gauge for how correct tension is actually measured and confirmed.
Read AIMS's full Diagnosing Improper Belt Tension or Misalignment Guide →
Shop AIMS's range of idler pulleys →
What Is Belt Tracking? (Conveyor)
Belt tracking is the ongoing process — and the idlers, frames and adjustments used to manage it — of keeping a conveyor belt running centred on its pulleys and Troughing Idler sets, rather than drifting ("mistracking") to one side. A belt that walks off-centre rubs against the frame, chews up its own edge, and can eventually run off the structure entirely if left uncorrected.
Mistracking is almost always a symptom of something else rather than a fault in the belt itself — a misaligned pulley or idler, uneven loading (material consistently landing off-centre), a build-up of material on an idler roller, or belt stretch from an incorrectly tensioned or ageing Carcass (Conveyor Belt). Self-aligning (training) idlers, which pivot slightly to steer the belt back to centre, are a common corrective fix, but they treat the symptom — proper practice is to find and fix the root misalignment first. See Belt Scraper (Conveyor Cleaner) and Skirting (Skirt Board, Conveyor) for two of the most common causes of the material build-up that drives mistracking in the first place.
What Is a Bench Vice? (Vise)
A bench vice — vise in American spelling — is a workbench-mounted clamping tool that holds a workpiece steady for filing, cutting, drilling, welding or assembly, freeing both of the user's hands the same way Locking Pliers do, but bolted to a fixed bench rather than held by hand.
The two main types cover different trades: an engineer's vice has hardened, serrated steel jaws suited to metalworking, where grip matters more than surface finish; a woodworking vice has smooth, often quick-release jaws designed not to mark timber. Size is specified by jaw width, and a heavier casting resists deflection under load better than a lighter one of the same jaw width — worth checking on a vice that will see genuine leverage, not just light bench work.
Read AIMS's full Bench Vice Guide →
What Is Bending Force?
Bending force is the load applied perpendicular to a beam, bracket or shaft's length that causes it to flex or deflect — as distinct from a tensile (pulling) or compressive (pushing) load applied along its axis. Engineers calculate the resulting bending moment (force × distance from the support point) to check whether a component will stay within its Elastic Range or permanently deform — the further from the support a given force is applied, the greater the bending moment it creates, which is why a long lever arm can bend a bracket that would easily support the same force applied close to its mounting point.
What Is Blind? (Rivet Installation)
"Blind" describes any rivet or fastener that can be fully installed from one side of the material only, with no access needed to the reverse (blind) side — the defining feature of the standard pop rivet, and the reason blind rivets and rivet nuts dominate sheet-metal and enclosed-structure work where the back of the panel simply can't be reached.
A blind rivet sets by pulling a mandrel through a hollow rivet body from the accessible side; the body deforms and bulges on the hidden side, clamping the joint, and the spent mandrel stem then breaks off and ejects. This is the opposite installation logic to a Structural Rivet in solid form (which needs two-sided access to buck the tail), and is the whole reason nutserts and blind rivets exist as a category. *(General fastening-industry terminology, cross-referenced against AIMS's own rivets guide.)*
Read AIMS's full Types of Rivets Guide → for blind rivet types and diameter ranges
Shop AIMS's range of rivets →
What Is a Blotter (Abrasive Wheel)?
A blotter is the paper or fibre disc bonded to each face of a Bonded Abrasive wheel, printed with the manufacturer's maximum safe operating speed, size and other compliance markings required under AS 1788. It stays on the wheel for its whole working life so the speed rating is always visible at a glance, right up until the wheel is worn down and discarded.
What Is a Blow Gun? (Pneumatic)
A pneumatic blow gun is a handheld nozzle used to direct compressed air at a workpiece or machine — clearing swarf, dust, water or general debris. It's a light, intermittent load, typically 2–5 CFM at 90 psi in short bursts rather than continuous use.
The safety requirement here isn't optional: when a blow gun nozzle is dead-ended (blocked, or pressed against skin), static pressure must not exceed 30 psi under SafeWork Australia guidance, because compressed air forced into the body through a skin abrasion, the ears or a wound can cause an air embolism — a genuinely life-threatening event, not a minor incident. A compliant nozzle has a venturi design or a relief port built in specifically to prevent dead-ending from reaching dangerous pressure; a cheap blow gun without that feature shouldn't be used on a compressed air line, full stop. Most workshop blow guns fit to the airline via a QC quick-connect plug at the tool station.
Read AIMS's full Air Tools Guide → for the full compliance requirement and safe nozzle types
Shop AIMS's range of air guns — blow, spray & cleaning →
What Is Bond Hardness? (Diamond Blade)
Bond hardness is how tightly the metal matrix on a Diamond Blade's rim holds its diamond particles in place — sold across a soft-to-hard spectrum and selected against the material being cut, rather than treated as a single "better or worse" spec.
The rule is genuinely counterintuitive and worth remembering: a soft bond suits hard material, and a hard bond suits soft or abrasive material. Hard material wears the bond down quickly enough to keep exposing sharp new diamond as the old diamond dulls, so a soft bond keeps pace with it — but that same soft bond would wear away too fast on soft, abrasive material, losing diamond before its cutting life is used up, which is exactly what a harder bond is chosen to prevent. Glazing — the blade spinning but no longer cutting — is the tell-tale sign of a bond-to-material mismatch, and general-purpose blades use a medium bond as the compromise.
Read AIMS's full Diamond Blade Guide → for bond hardness selection by material
What Is Bond Type — Vitrified, Resinoid or Rubber?
Bond type describes what holds a Bonded Abrasive's grain together. Vitrified bond is a fired ceramic bond — rigid, porous and free-cutting, the standard choice for bench-grinder wheels where dimensional stability matters more than shock resistance. Resinoid bond uses a synthetic resin — tougher and more able to flex under the shock and side-loads of high-speed cutting and grinding discs. Rubber bond is the most flexible and resilient of the three, used where a wheel needs to absorb impact without shattering, such as thin cut-off wheels and regulating wheels in centreless grinding.
What Is a Bonded Abrasive?
A bonded abrasive is abrasive grain held together with a bonding agent — vitrified, resinoid or rubber, see Bond Type — into a solid shape such as a Grinding Wheel or Cutting Disc, as opposed to a coated abrasive, where grain is glued to a flexible backing like Sandpaper. Because the whole shape is abrasive rather than just a coated surface, a bonded abrasive keeps cutting at full width and profile for its entire working life, right down to the last usable diameter.
What Is a Bore Gauge?
A bore gauge is an instrument used to measure the internal diameter of a hole or cylindrical bore, filling the gap left by an outside micrometer or caliper, neither of which can reach an internal surface directly. AIMS's own guide covers four distinct families, each suited to a different bore range and accuracy: the telescopic gauge (roughly 8–150mm, accurate to about ±0.005mm in skilled hands, spring-loaded plungers that expand to the bore wall, are locked, then read externally with a micrometer — needs no setting master, the standard choice for general workshop and one-off jobs); the small hole (split-ball) gauge (roughly 3–13mm, for bores too small for a telescopic gauge — valve guides, carburettor jets, small bearings); the dial bore gauge (roughly 6–300mm, accurate to about ±0.0025mm with a properly set master, self-centring contact points read on a precision dial — the choice for repeated engine-cylinder or bearing-housing measurements); and the internal (bore) micrometer (roughly 5–500mm, accurate to about ±0.002mm on three-point models, which self-centre and need no external master at all). The practical trap AIMS's guide flags: buying a dial bore gauge without budgeting for the setting master (a ring gauge or gauge block stack) it needs to read true — without one, the gauge has nothing to zero against.
Read AIMS's full Bore Gauge Types Guide → for the full range, accuracy and selection comparison
Shop AIMS's range of measuring tools →
What Is a Bow Shackle?
A bow shackle (also called an anchor shackle) is a Shackle with a rounded, wider body, rated for both straight and side-loaded (angled) lifts. This is the shackle to reach for whenever a load will be pulled from more than one direction — a straight D-Shackle isn't rated for that.
Shop AIMS's range of shackles →
What Is Brake Chamber?
A brake chamber is the air-actuated cylinder, mounted at each brake assembly, that converts stored air pressure into the mechanical push-rod force needed to apply the brake — when the driver presses the pedal, air enters the chamber and drives a diaphragm and push-rod against the Slack Adjuster, which rotates the S-Cam to force the brake shoes outward. Many heavy-vehicle chambers are a combined service/park design (a spring brake section that mechanically applies the park brake when air pressure is deliberately released), which is why a heavy vehicle's park brake stays applied with the engine off and no air pressure in the system.
What Is Brass?
Brass is a copper-zinc alloy prized for corrosion resistance, low friction, good machinability and — critically for plumbing and pneumatic work — the fact that it doesn't spark on impact, making it a safe choice around flammable atmospheres.
It's the standard material for pipe fittings, hose fittings, valves, gland fittings and low-load bushes where steel would corrode too quickly and plastic wouldn't take the pressure or temperature. Higher zinc content increases strength but can make brass more prone to a corrosion pattern called dezincification in aggressive water; standard trade-grade brass fittings handle typical compressed-air and water-reticulation duty without issue.
Shop AIMS's range of brass fittings →
What Is a Bridge Reamer?
A bridge reamer is a long, taper-shanked reamer with extended cutting length and an aggressive flute design, originally developed for structural steelwork — aligning and finishing mismatched bolt holes in heavy fabrication where a standard-length Reamer can't reach or correct the misalignment between stacked steel plates. It's a specialist, heavy-fabrication tool rather than a general workshop item, used specifically where bolt holes in structural steel need to be brought into true alignment before the bolts go in.
Read AIMS's full Reamer Guide → for the full reamer family and standards
Shop AIMS's range of reamers →
What Is the Brinell Hardness Scale (HB)?
The Brinell scale (HB) rates a material's hardness by pressing a 10mm tungsten carbide ball into the surface — typically under 3,000 kgf load for steel — and measuring the diameter of the resulting indentation under a microscope: the wider the indentation for a given load, the softer the material. Brinell is the standard choice for coarse-grained or non-uniform materials — castings, forgings, weld heat-affected zones — where a smaller, more precise Rockwell or Vickers indent risks landing on an unrepresentative grain or inclusion and skewing the reading; the larger Brinell indent averages out over more material. It's tested in Australia under AS 1816 (aligned to ISO 6506-1 and ASTM E10). See Rockwell Hardness and Vickers Hardness below for the other two scales AIMS deals with most, and Hardness for how the three relate and convert.
Read AIMS's full Hardness Testing Guide → for the complete scale, indenter and standards comparison
What Is Brinelling (Bearing Failure)?
Brinelling is permanent indentation damage to a bearing's Race, spaced at the same pitch as the rolling elements, caused by fitting force (or a shock/hammer blow) passing through the rolling elements instead of being applied to the ring actually being fitted — see Interference Fit for the correct method. It can happen before the bearing has even been put into service, purely from mishandling during installation.
A related but distinct failure — false brinelling — produces similar-looking marks but comes from vibration acting on a stationary bearing (commonly in transit or storage) rather than a single fitting-force event, and is technically a fretting-corrosion failure rather than true brinelling.
Read AIMS's full Bearing Maintenance: Inspection, Lubrication & Replacement Guide →
Shop AIMS's range of bearing pullers →
What Is Brooker Rod?
Brooker Rod is an Australian trade name for Allthread (threaded rod, studding) above — a genericised brand name that's become common shorthand for fully threaded rod in general Australian trade usage, in the same way "Nyloc®" and "Molly" are now used generically for their respective fastener types regardless of manufacturer.
Whichever name a customer uses, it describes the same product: steel rod threaded along its entire length, cut to length and paired with nuts and washers on both sides of the clamped material. See Allthread above for grades, finishes, stock lengths and the thread-engagement rule that applies regardless of which name is used to search for it.
Read AIMS's full Threaded Rod Guide → for grades, finishes and the coupling-nut joining method
Shop AIMS's range of all-thread rod →
What Is BS 4278?
BS 4278 is the British standard for collared eye bolts — the eye bolt type with a machined shoulder flange that lets it be safely loaded at an angle, unlike a plain DIN 580 eye bolt. See Eye Bolt above for the full plain-vs-collared comparison and angular de-rating detail.
What Is BSF (British Standard Fine) Thread?
BSF (British Standard Fine) is the finer-pitch companion to BSW (British Standard Whitworth) Thread above, sharing the same 55° flank angle and nominal diameter range but with more threads per inch at each size — used historically wherever finer adjustment or better vibration resistance was needed than BSW's coarser pitch could offer.
Like BSW, BSF is a legacy standard from before Australia's 1970 metric conversion, now encountered mainly on older British-derived machinery, motorcycles and restoration work rather than in new manufacturing. AIMS still stocks BSF hand taps for exactly this kind of maintenance and repair work on legacy equipment.
Read AIMS's full Metric to Imperial Fastener Conversion Chart → for BSF TPI by nominal size
Shop AIMS's range of hand tap sets →
What Is BSP? (British Standard Pipe)
BSP (British Standard Pipe) is the thread standard used across most of Australia's plumbing, pneumatic and hydraulic fittings — a 55° thread form that comes in two genuinely different variants, BSPT / BSPP, which seal in completely different ways and aren't visually obvious to tell apart without checking.
BSP is not interchangeable with NPT (National Pipe Thread), the American equivalent, despite both being tapered pipe thread systems that can sometimes be forced to screw together — the different thread angles mean the contact is only partial, which shows up as stress concentration, thread damage on first assembly, and eventual pressure failure rather than a working seal.
Read AIMS's full Hydraulic Fittings Guide →
Shop AIMS's range of hydraulic fittings →
What Is BSPP? (Parallel)
BSPP (parallel) is one of the two genuinely different sealing methods hiding under the single BSP name — a straight, parallel thread that doesn't wedge at all, unlike the tapered BSPT. The seal instead comes from a bonded seal (a Dowty washer) or an O-ring compressed on a machined face between the fitting and the port.
The practical way to tell it apart from BSPT without a spec sheet: measure the thread outside diameter at two points along its length with a calliper — a parallel (BSPP) thread reads the same diameter at both points, while a tapered (BSPT) thread reads visibly smaller near the tip. Mixing them up — using thread sealant on a BSPP fitting that actually needs a bonded seal, or vice versa — is a common and avoidable cause of a leak that looks like a faulty part.
Read AIMS's full Hydraulic Fittings Guide and Dowty Washer & Bonded Seal Guide →
Shop AIMS's range of hydraulic fittings →
What Is BSPT? (Tapered)
BSPT (tapered) is one of the two genuinely different sealing methods hiding under the single BSP name — a 1:16 taper and a wedging thread action sealed with thread sealant or PTFE tape, unlike the straight, parallel BSPP thread.
The practical way to tell it apart from BSPP without a spec sheet: measure the thread outside diameter at two points along its length with a calliper — a tapered (BSPT) thread reads visibly smaller near the tip, while a parallel (BSPP) thread reads the same diameter at both points. Mixing them up — using thread sealant on a BSPP fitting that actually needs a bonded seal, or vice versa — is a common and avoidable cause of a leak that looks like a faulty part.
Read AIMS's full Hydraulic Fittings Guide and Dowty Washer & Bonded Seal Guide →
Shop AIMS's range of hydraulic fittings →
What Is BSW (British Standard Whitworth) Thread?
BSW (British Standard Whitworth) is the original British coarse-pitch thread standard, distinguished from later metric and Unified (UNC/UNF) threads by its 55° flank angle (rather than the 60° used by both ISO metric and UNC/UNF) and by rounded, rather than flat, crests and roots.
BSW predates Australia's 1970 metric conversion and is still encountered on pre-1970s British-derived machinery, older agricultural equipment, and heritage/restoration work. BSF (British Standard Fine) is BSW's finer-pitch companion at the same nominal sizes — see below — and neither is interchangeable with a metric or UNC/UNF thread of similar nominal diameter, since flank angle mismatches cause poor thread engagement even when the pitch happens to be close.
Read AIMS's full Metric to Imperial Fastener Conversion Chart → for BSW TPI by nominal size
Shop AIMS's range of hand tap sets →
What Is a Buffing Wheel?
A buffing wheel (also called a polishing mop) is a soft wheel — sisal, cotton, felt or stitched calico — run at lower speed than an abrasive Grinding Wheel and charged with a polishing or buffing compound, cutting and colouring a metal surface to a mirror finish through the compound's fine abrasive rather than removing significant material the way a grinding or sanding operation does. It's the finishing step after any coarser abrasive work, not a replacement for it. AIMS stocks buffing wheels themselves (Abbott & Ashby calico polishing mops, Maxigear non-woven polishing mops) alongside the compounds charged onto them; there's no single dedicated collection page covering the wheels specifically, so they're mentioned here by product rather than linked.
Read AIMS's full Bench Grinder Guide → for how polishing and buffing wheels compare with abrasive grinding wheels on the same machine
Shop AIMS's range of polishing compounds →
What Is a Bulb (Bulge) Rivet?
A bulb (bulge) rivet is a structural blind rivet designed so the mandrel locks *inside* the rivet body once set, forming a substantially larger, mechanically-locked bulge on the blind side than a standard pop rivet produces — giving it dramatically higher shear and pull-through strength for genuinely structural, load-bearing joints.
Branded examples include Gesipa® BULB-TITE® and Huck Magna-Lok®, with typical shear ratings in the 8–15 kN range — well beyond what a standard aluminium or steel pop rivet can carry, and specified anywhere a joint needs to be genuinely structural but only has single-side access. See Structural Rivet and Pre-bulbed below for the closely related terms in this same family.
Read AIMS's full Types of Rivets Guide → for structural blind rivet types and shear ratings
What Is a Butterfly Valve?
A butterfly valve is a quarter-turn rotary valve where a disc rotates on a stem across the pipe bore — parallel to the flow for fully open, rotated 90° to sit perpendicular to flow for fully closed — making it faster to operate and generally more compact and lighter than an equivalent Gate Valve.
Body style determines how it installs: wafer (sandwiched between two pipe flanges by the flange bolts themselves, and not usable as a line-end valve), lug (threaded inserts let it bolt independently to each flange, allowing genuine downstream isolation), flanged (standard on larger valves from DN300 up), or grooved (couples to grooved pipe systems, common in fire protection and HVAC). Disc design is the other major selection axis: concentric (the most economical, standard for water, air and low-pressure service, typically PN10–PN16) rubs across the seat on every open/close cycle; double-offset (also called high-performance) lifts the disc clear of the seat immediately on opening rather than rubbing, rated to PN25 and suited to steam and higher temperatures; and triple-offset uses a metal-to-metal cone-on-cone seat, eliminating elastomer temperature limits entirely and handling everything from cryogenic service to 500°C. Butterfly valves can throttle, but with a distinctly non-linear response — most of the flow change happens in a narrow 40°–60° opening window, and a concentric-disc design isn't suited to prolonged throttling below about 20° open in high-velocity service. See Quarter-Turn Valve for the broader category this valve type shares with the ball valve.
Read AIMS's full Butterfly Valve Guide →
Shop AIMS's range of pipe fittings →
What Is a Button Die?
A button die (solid die) is a round, unslotted die held in a Die Stock, used to cut a fresh external thread onto round stock from scratch — the direct counterpart to a tap, which cuts internal threads. Because a button die has no radial slot, it cuts to one fixed diameter with no adjustment possible, but that same solid construction makes it cut more accurately and last longer than an adjustable split die, whose slot weakens the body. See Die Nut below for the different tool used to clean up or restore an already-cut thread rather than cut a new one, and don't confuse the two — a die nut's hexagonal geometry makes it unsuitable for cutting fresh threads on bare, unthreaded stock.
Read AIMS's full Tap & Die Selection Guide → for solid vs split die selection and standards (ISO 261, ISO 529)
Shop AIMS's range of threading dies →
C
What Is a C-Clamp?
A C-clamp is a C-shaped frame clamp with a screw-driven jaw at the open end, used to hold a workpiece to a bench or hold two parts together — for gluing, welding or general assembly — while both of the user's hands are free to work.
The screw-driven jaw gives strong, precise clamping force in a compact frame, at the cost of reach — a C-clamp's throat depth is fixed by its frame size, unlike an F-Clamp / Bar Clamp's sliding rail, which can clamp across a much wider span. See G-Clamp for the AU/UK name for essentially the same tool.
Read AIMS's full Clamp Types Guide →
What Is C3 / C4 Internal Clearance?
Internal clearance is the radial play between a bearing's rolling elements and its races at rest, and C3/C4 are grades of that clearance looser than the CN "normal" default — C3 being the next step up, C4 looser again. AIMS's own guide gives the practical reason this matters: as a bearing runs and heats up, its inner ring expands faster than the outer, and a CN-clearance bearing can end up preloaded (and prematurely failed) purely from thermal growth — which is why electric motor bearings almost universally specify C3 as standard, not as an upgrade.
As a rule of thumb from AIMS's own guide, roughly 80% of the interference fitted between a bearing's inner ring and its shaft shows up as a reduction in that bearing's operating clearance — which is why getting the clearance grade right at selection time matters more than it might look on paper.
Read AIMS's full Deep Groove Ball Bearing Guide: 6200/6300, Seals & Brands →
What Is Cable Conduit — Rigid, Flexible & Corrugated?
Cable conduit is a tube that fully encloses and protects electrical cabling along its run, as distinct from Cable Tray, which supports cables openly rather than enclosing them — conduit and fittings for AU electrical installations are covered under AS/NZS 2053, with rigid, flexible and corrugated variants suited to different mounting and movement requirements (rigid for fixed straight runs, flexible and corrugated where the conduit needs to bend around obstructions or absorb vibration). The choice between conduit and open tray generally comes down to how much physical protection and how much dust/moisture sealing the run needs.
Read AIMS's full Cable Management Guide → for conduit, tray and gland selection
What Is a Cable Gland?
A cable gland is a fitting that terminates a cable where it enters an enclosure, clamping the cable to provide Strain Relief and sealing the entry point against dust and moisture ingress. Cable glands are specified to match both the cable diameter and the enclosure's required IP Rating (Ingress Protection).
Glands are sized and threaded to a small number of standard series — metric (M12 through M63) is the current AS/NZS-aligned standard, while the older PG thread series (PG9, PG11 and similar) still turns up on imported equipment. Getting the size right matters more than it looks: a gland specified for a 6–12 mm cable won't seal properly on either a 4 mm cable (no compression left on the seal) or a 14 mm cable (won't close at all), so the gland's stated cable range — not just its thread size — needs to match the actual cable. Material choice follows the environment: nylon for general indoor and light outdoor use, brass or nickel-plated brass as the industrial workhorse for outdoor and machinery applications, and stainless steel (316 specifically) for marine or other chloride-heavy environments. On armoured cable, a gland also has to maintain electrical bonding continuity to the earth conductor — not just a mechanical seal — which is one more reason a gland can't simply be swapped for "something the same size."
Read AIMS's full Cable Management Guide → for gland, tray, ladder and conduit selection
What Is Cable Tray — Ladder, Basket & Trunking?
Cable tray is an open, ladder-style or perforated metal containment system that carries and supports multiple cables along a routed path, typically overhead in industrial and commercial buildings. It comes in several forms, and the choice between them mostly comes down to how far apart the supports need to be and how much the tray needs to protect against: perforated solid-bottom tray gives the most physical protection and typically needs support every 1.2–1.5 m; ladder tray (two rails joined by transverse rungs) spans much further between supports — up to around 6 m — at the cost of less underneath support for the cables themselves; and basket (wire mesh) tray, common in data and comms installations, sits in between, generally on a similar support spacing to solid tray. Where cables need to be fully enclosed rather than just supported, Cable Conduit is the alternative, and where several trays or a mix of tray and conduit are used on one project, AS/NZS 3013 (fire resistance of electrical support systems) and AS/NZS 3000's cable-grouping de-rating rules both come into play once fill levels get high.
Read AIMS's full Cable Management Guide → for tray, ladder, basket and conduit span and standard references
Shop AIMS's range of wire and cable management →
What Is Cadmium Plating?
Cadmium plating is a corrosion-resistant, naturally lubricious metal coating historically applied to high-strength steel fasteners — particularly in aerospace and defence work — valued for combining strong protection against humidity, rain and salt spray with a smooth surface that reduces installation friction and can deform slightly under vibration without damaging the underlying fastener.
Cadmium is classified as toxic and its use is restricted by environmental and workplace-safety regulators internationally, which is why zinc-based platings (see Zinc Plated vs Galvanised in AIMS's own coatings guide) have become the preferred general-purpose alternative — zinc offers less corrosion resistance than cadmium in the harshest environments, but avoids the toxicity and disposal concerns. Cadmium-plated fasteners are also, like any electroplated high-strength fastener, subject to Hydrogen Embrittlement risk and require Baking as part of the plating process. *(Independent standards/industry source — no dedicated AIMS article, and AIMS does not stock cadmium-plated fasteners as general trade stock given the regulatory restrictions.)*
What Is a Cage (Bearing Retainer)?
A cage — also called a retainer — is the component inside a rolling-element bearing that spaces the Rolling Elements evenly around the Race and stops them contacting each other. It carries no load itself; its only job is to maintain that spacing, which is why a collapsed or fractured cage — rather than the rolling elements or races themselves — is often the actual point of failure in a bearing that's been badly overloaded or run without lubrication.
Cage material varies with duty: pressed steel and polyamide (nylon) cages are standard for general industrial bearings, while brass or bronze cages turn up in higher-speed or higher-temperature applications where a polymer cage would soften or wear.
Read AIMS's full Rolling Bearings: Types, Selection, Fitting & Failure Guide →
What Is Calcium Sulfonate (Complex) Grease?
Calcium sulfonate complex grease is a premium thickener chemistry with strong water resistance and high load-carrying capacity, used in marine, mining and oil-and-gas drilling applications up to around 180°C. It's the specific grease to reach for in consistently wet or water-contaminated environments where even Aluminium Complex Grease isn't robust enough, and AIMS's own material notes it as the go-to alternative wherever a Moly Grease application also needs to handle sustained wet conditions, since MoS2 itself degrades under prolonged water and oxygen exposure.
Shop AIMS's range of greases →
What Is Calibration?
Calibration is the process of comparing a measuring instrument against a known, traceable reference standard and adjusting or documenting any deviation from true, so the instrument can be relied on to read accurately. It isn't a one-off event — every precision instrument drifts with use, knocks and age — so calibration is done on a recurring schedule rather than assumed to hold indefinitely. As a general guideline, most workshop measuring equipment should be recalibrated at least once a year, production inspection equipment every 6–12 months, and safety-critical equipment (aerospace, medical) every 3–6 months or more often — though there's genuinely no one-size-fits-all interval, and manufacturer recommendations and the specific application should drive the actual decision. See NATA and Traceability (Calibration) below for what turns a calibration into something that actually holds up under audit.
Read AIMS's full guide to calibration intervals → for interval guidance by equipment type
What Is a Calliper?
A calliper is a hand-held precision measuring tool with a pair of jaws that close onto a workpiece, used to measure outside dimensions (diameter, width), inside dimensions (bores, grooves), depth, and step or shoulder height — reading finer than a Steel Rule alone can manage. AIMS stocks three distinct readout types, and the right choice comes down to working conditions rather than one simply being "better": the Vernier Caliper (no battery, reads via aligned scale markings, the most robust choice in wet or oily conditions); the Digital Caliper (LCD readout, fastest to read, the right call when you're taking a high volume of measurements); and the Dial Caliper (mechanical rack-and-pinion dial, no battery, a middle ground between the two). See each entry below for the full detail on how each type works and where it's best suited.
Shop AIMS's range of measuring tools →
What Is a Camlock Fitting?
A camlock — also called a cam and groove coupling — is a quick-connect hose fitting that joins and releases in seconds using two lever-operated cam arms, rather than needing to be threaded together like a standard BSP or NPT connection.
Eight standard types cover every combination a system needs: Type A, E and F are male adapters (A screws onto a male-threaded pipe nipple, E is barbed for a hose tail, F is the rarer male-to-male thread version), while Type B, C and D are female couplers (C, barbed for a hose tail, is the most common hose-end pairing, alongside Type DC and DP dust caps/plugs that protect a disconnected fitting from contamination). The workhorse combination in the field is a Type A adapter on a pump outlet mating with a Type C coupler on the hose — connect by inserting the male adapter against the gasket and pushing both cam arms down until they catch the adapter's groove. Material selection follows the same logic as STAMPED: standard metal camlocks (aluminium or brass) are rated 250 psi (17 bar) cold on 1/2"–2" sizes, dropping to 150 psi on 2½"–4" sizes, while polypropylene and Nyglass versions for acid/alkali service typically cap out around 100 psi regardless of size — and that rating derates sharply with temperature, so a fitting good for 250 psi at 22°C might only hold 70 psi at 100°C. The single most common camlock failure is the cam arms popping open under pressure, vibration or impact — a genuine risk controlled with safety pins, R-clips or self-locking arm designs, not something to leave to chance on a pressurised line.
Read AIMS's full Camlock Fittings Guide →
Shop AIMS's range of camlock fittings & cam and groove couplings →
What Is Capacitor Start / Capacitor Run (Single-Phase Motor Types)?
A single-phase Induction Motor can't self-start on its own — the single-phase stator field pulsates rather than rotates, so it produces no net starting torque without help. Capacitor Start (CS) solves this with a start capacitor wired into a separate start winding, giving high starting torque, then disconnected by a centrifugal switch once the motor is up to speed. Capacitor Start / Capacitor Run (CS/CR) goes further, keeping a second, smaller run capacitor in circuit permanently — it delivers the same strong start plus better running efficiency and power factor, and is the preferred type for most industrial single-phase applications with hard-starting loads like compressors and pumps.
Two lighter-duty variants cover the rest of the range: Permanent Split Capacitor (PSC) uses a single run capacitor with no switching at all, suited to smooth, quiet, low-torque loads like fans and blowers; Shaded Pole uses no capacitor, just a copper ring on the stator to create a starting phase shift, and is only suited to very light loads such as small instrument fans. See Star-Delta (Y-Δ) Starting, DOL (Direct-On-Line) Starting, Soft Starter and VFD (Variable Frequency Drive) for the equivalent three-phase starting methods.
Read AIMS's full Electric Motor Guide → for the full single-phase motor type comparison table
Shop AIMS's range of electric motors →
What Is a Captive Nut?
A captive nut is a nut permanently retained in position on or within a panel — welded, riveted, or held in a floating cage — so that a bolt can be driven in from the front face without anyone needing to hold a loose nut on the blind side.
Captive nuts solve exactly the same one-sided-access problem a Rivnut / Rivet Nut solves, but by retaining a genuine full nut (rather than forming a thread directly in the panel), which generally gives higher pull-out and torque capacity for a given size — the trade-off is that a captive nut usually needs to be installed (welded, riveted or clipped in) before the panel is fully assembled, where a rivet nut can be installed afterwards from one side alone.
Shop AIMS's range of captive nuts →
What Is a Carbide Burr (Rotary Burr)?
A carbide burr is a rotary cutting tool with a tungsten carbide head brazed to a steel shank, spun at anywhere from around 12,000 up to 90,000 RPM in a die grinder to cut, shape and deburr metal, hard plastics and composites — it removes material by cutting with defined helical teeth, not by abrasion, which is the key difference from every other entry in this category. Common head shapes include ball (SD), cylindrical (SA/SC), tree (SF) and flame (SH), each suited to different internal or external profiles, and cut pattern (single, double or diamond cut) is matched to the material — double cut for steel and stainless, single cut for soft, gummy metals like aluminium and brass where a coarser chip gullet resists clogging.
Read AIMS's full Carbide Burr & Rotary Burr Guide → for shape codes, cut types and RPM by head size
Shop AIMS's range of carbide burrs →
What Is Carbon Fibre?
Carbon fibre is a composite material built from thin strands of woven or unidirectional carbon filament set into a resin matrix — usually epoxy — giving an exceptionally high strength-to-weight ratio that outperforms steel and aluminium by a wide margin on a like-for-like weight basis.
It's a genuinely different material family from the aramid fibres (Kevlar®, HPPE) covered elsewhere in this glossary: aramid fibres are prized for toughness and cut/impact resistance in flexible applications like gloves and protective fabric, while carbon fibre is stiff and brittle rather than tough, making it suited to rigid structural applications instead — motorsport chassis and body panels, aerospace components, high-performance bicycle frames, and drone airframes. Carbon fibre's stiffness is also highly directional, following the fibre weave, which is why a genuinely engineered carbon fibre part is laid up with specific fibre orientations for the loads it needs to carry, not simply moulded like a uniform plastic.
What Is Carcass? (Conveyor Belt)
The carcass is the internal reinforcing layer of a conveyor belt — the fabric-ply or steel-cord structure sandwiched between the top and bottom rubber covers — that actually carries the tension pulling the belt around the system and supports the load sitting on top of it. It's the belt's structural core: strip away the rubber and the carcass is what's left doing the engineering work.
Most general industrial belting uses a fabric carcass — multiple plies of woven polyester/nylon (EP) fabric bonded together with rubber — while higher-tension or long-centre-distance belts step up to steel-cord construction, where parallel steel cables replace the fabric plies for minimal stretch. The carcass also determines how a belt can be joined (see Endless Splice and Mechanical Fastener (Conveyor Belt)), and its condition is a standard wear check: AIMS's own conveyor components guidance flags a "worn cover exposing carcass" as one of the visual signs a belt is due for replacement. See PIW Rating (Pounds per Inch of Width) for how carcass strength is actually specified, and Cover Compound (Conveyor Belt) for the protective layer bonded either side of it.
Shop AIMS's range of conveyor components & steel rollers →
What Is a Cartridge Bearing Unit?
A cartridge bearing unit is a bearing pre-mounted inside a close-tolerance cylindrical housing designed to fit directly into a machined bore in a structure or piece of equipment, rather than bolting on top of or against a surface like a Pillow Block or Flanged Bearing Unit does. That close-tolerance fit gives accurate shaft location in both radial directions and lets the whole unit be replaced as a single item without disassembling the surrounding structure.
Read AIMS's full Pillow Block Bearing Guide: UCP, UCF, UCFL & Plummer →
Shop AIMS's range of bearing housings →
What Is Cast Iron?
Cast iron is an iron-carbon alloy with a higher carbon content than steel (typically over 2%), giving it excellent compressive strength, vibration damping and wear resistance — but making it brittle under sudden impact or bending load compared with steel.
That combination of stiffness and vibration damping is exactly why cast iron is the standard material for bearing housings (pillow blocks, flange units, take-up units): it holds its shape under running load and dampens the vibration a bearing generates, rather than transmitting it into the surrounding structure. Grey cast iron (the common workshop grade) is not weldable by ordinary methods and should never be substituted where a design calls for ductile iron or steel.
Shop AIMS's range of bearing housings →
What Is a Castor? (Castor Wheel)
A castor is a wheel-and-bracket assembly fitted to trolleys, workbenches, machinery and other equipment to give it mobility — swivel castors rotate freely for manoeuvring in any direction, fixed castors roll in one direction only for stability, and braked versions lock the wheel (and sometimes the swivel action too) once the equipment is in position.
Load rating is the critical selection figure: a castor rated below the equipment's actual loaded weight will fail early or roll poorly under load, and the wheel material itself needs to suit the floor surface and environment — a soft rubber tread marks and struggles on rough concrete, while a harder polyurethane or nylon wheel copes with rough or contaminated floors but transmits more vibration and noise.
Read AIMS's full Castor Wheel Guide →
Shop AIMS's range of castor wheels — swivel, fixed & braked →
What Is Cathodic Barrier Protection?
Cathodic barrier protection combines both mechanisms in Barrier Protection and Anode / Cathode sacrificial protection in a single coating system: a physical barrier layer that excludes moisture, backed by a coating (typically zinc-rich) that also acts sacrificially at any point the barrier is breached. Zinc Plating and Hot Dip Galvanizing are the two most common real-world examples AIMS stocks — the zinc layer is both a barrier and, once breached, a sacrificial anode protecting the steel beneath it.
This entry is written to established corrosion-science fundamentals rather than an AIMS source.
What Is Caulk?
Caulk is a flexible sealant — commonly silicone, acrylic or polyurethane based — applied as a continuous bead along a joint or gap to seal it against water, air or dust, while allowing for a degree of ongoing movement.
It's essentially a general trade name for a Joint Sealant product, and the same RTV and PU (Polyurethane) chemistries covered elsewhere in this glossary are what most caulking products are actually made from.
Shop AIMS's range of adhesives, sealants & tapes →
What Is CBU? (Completely Built-Up)
CBU stands for Completely Built-Up — a vehicle, machine or piece of equipment that's fully assembled by the manufacturer before it's shipped, arriving ready to use (or very close to it) rather than requiring local assembly.
It's the opposite end of the spectrum from CKD (Completely Knocked-Down) and SKD (Semi-Knocked-Down), and the three terms are usually discussed together when comparing import strategies for vehicles, generators, compressors and other larger equipment. A CBU import is simpler logistically (no local assembly line needed) but can attract higher import duty in markets that use duty rates to encourage local assembly — a consideration for anyone specifying or sourcing imported industrial equipment. Worth a quick note since the letters are similar: CBU is a completely different acronym from PCBU (Person Conducting a Business or Undertaking, the WHS legal term) — no relationship between them beyond sharing three letters.
What Is Cementite?
Cementite is iron carbide (Fe₃C) — a very hard, brittle compound that forms within steel and cast iron as carbon content increases, and it's a major reason why higher-carbon steels are harder but less ductile than mild steel.
It's a background metallurgical term rather than a buying consideration: cementite content is what's really being controlled when carbon content, hardness and brittleness are discussed together in steel specifications.
What Is a Centre Punch?
A centre punch is a hand tool used to mark a precise starting point for a drill bit — a sharp point struck with a hammer leaves a small indent that stops the bit "walking" (skating sideways) when drilling begins, especially on a smooth or curved metal surface.
An automatic centre punch does the same job without a hammer, using an internal spring mechanism triggered by pressing the punch down onto the work — useful one-handed, or where swinging a hammer isn't practical. See Scriber for the companion layout tool used to mark the lines a centre punch's mark then sits on.
Read AIMS's full Centre Punch & Scriber Guide →
What Is a Cermet (Cutting Tool Material)?
Cermet is a ceramic-metal composite cutting tool material — typically titanium carbide or titanium nitride bonded with a nickel or cobalt binder — with a hardness around 1,500 HV, sitting between Solid Carbide (VHM) and the ultra-hard PCBN/PCD materials on the cutting-tool hardness scale. Its defining trade-off is extreme brittleness: cermet delivers a superior surface finish to carbide at light depths of cut and high speed, which makes it a genuinely good choice for finishing passes on steel and stainless steel, but that same brittleness rules it out entirely for roughing cuts, interrupted cuts, drilling (the entry shock cracks it) or tapping (multi-edge engagement risk). See ISO 513 K-Grade Carbide Classification below for how cermet sits alongside tungsten carbide in the broader material-selection system.
Read AIMS's full Cutting Tool Materials Guide → for the full material hierarchy and hardness/toughness trade-off
What Is CFM? (Cubic Feet per Minute)
CFM — cubic feet per minute — is the imperial unit of airflow (volumetric flow rate) still used as the default spec unit for fans, heaters and ventilation equipment sold in Australia, despite the country being otherwise metric. One CFM converts to roughly 1.7 m³/h, or about 0.47 L/s.
CFM is how an HVLS Fan, a Mancooler, an Evaporative Cooler (Industrial) and workshop mechanical ventilation systems under AS 1668.2 are all rated and sized. A practical sizing formula, based on Air Changes per Hour (ACH), converts a workshop's volume straight into the CFM figure needed: Required CFM = (workshop volume in m³ × target ACH) ÷ 1.7. Target ACH itself depends on what's happening in the space — roughly 6–10 ACH for general workshop and light manufacturing, 10–15 ACH for a welding or fabrication bay, and 15–20 ACH for foundry, hot work or spray-painting areas, climbing higher again for toxic fume work.
Read AIMS's full Industrial Cooling Guide →
What Are Chain Block Components — Load Brake, Gear Housing & Hand Chain?
A chain block (chain hoist) is a hand-operated lifting device that uses a gear reduction inside its housing to let one person lift loads well beyond their own strength by pulling an endless hand chain. The load brake is the mechanism — usually a ratcheting friction disc — that holds the load in place the instant the hand chain stops moving, preventing free-fall if it's released mid-lift; the gear housing is the sealed gearbox that provides the mechanical advantage (the gear ratio, typically stated on the body, e.g. "4:1" or "abt. 40" pulls per metre of lift, is what trades hand-chain effort for lifting speed); the hand chain is the endless loop the operator pulls to drive the mechanism, sized so it doesn't need re-gripping mid-stroke on a standard lift height. A Lever Block (Lever Hoist) uses the same load-brake principle but is driven by a ratcheting lever instead of a hand chain, for tensioning and precise positioning work rather than vertical lifting.
Read AIMS's full Chain Block Guide → for gear ratio, headroom and load-brake selection
Shop AIMS's range of chain blocks and lever hoists →
What Is a Chain Breaker?
A chain breaker is a hand tool that presses a roller chain's pin out to separate the chain at any link — or presses a pin back in to rejoin it — without needing a Sprocket-side connecting link at that point. It's the alternative to using a connecting link (also called a master link, which clips or cotters on rather than needing a press), and is the standard way of shortening a length of roller chain to the exact number of pitches a drive calls for.
AIMS doesn't currently have a dedicated article on chain breakers specifically, so this entry is written to general trade knowledge rather than a cited AIMS source — included on relevance to the trade per the coverage principle, alongside Sprocket and the wider roller-chain vocabulary.
Shop AIMS's range of chain and sprockets →
What Is Chain Lube?
Chain lube is lubricant formulated specifically for roller chain — a genuinely different job from Grease or Penetrating Oil, since it needs to wick into the tight pin-and-bushing clearances inside a moving chain rather than simply coat an external surface. AIMS's own guide splits it into four types: wet (oil-based, stays fluid, best for outdoor and wet conditions but attracts contamination and needs frequent reapplication), dry/PTFE (a solid lubricant in a solvent carrier that evaporates to leave a dry film — clean but low load capacity and washed out by water), wax-based (hardens inside the chain's internal clearances rather than sitting on the surface, so it doesn't pick up dirt, but needs 20–30 minutes cure time and can't go over existing oil), and light industrial chain oil (ISO VG 46–68, drips or brushes on and wicks in by capillary action).
The one rule that applies regardless of type: apply lubricant to the inner side of the chain — the link rollers and inner link plate edges — not the outer plates, since that's where lubricant actually reaches the pin-bushing interface where most wear happens.
Read AIMS's full Chain Lube Guide: Wet, Dry, Wax & Industrial Types Explained →
What Is Chain of Responsibility (CoR)?
Chain of Responsibility is the framework under Australia's Heavy Vehicle National Law that extends legal responsibility for a heavy vehicle's safe, compliant operation beyond the driver alone — to schedulers, loaders, consignors, operators and anyone else in the transport supply chain whose decisions can affect mass, dimension, loading, fatigue or speed outcomes on the road. In practice it means a business that pressures a driver into an unsafe schedule, or loads a vehicle beyond its rating, can be held liable alongside (or instead of) the driver. Load Restraint failures are one of the most common CoR enforcement areas, since incorrect lashing capacity or an overloaded trailer implicates the loader and operator, not just whoever was behind the wheel.
What Is a Chain Sling?
A chain sling is a lifting sling made from grade-rated alloy steel chain, used where a job needs high resistance to heat, abrasion or sharp edges that would cut through a synthetic webbing sling. AIMS's own chain sling range is built and rated to AS 3775.1 & AS 3775.2.
A chain sling's rated capacity depends on the rigging configuration used — the Hitch Types (vertical, choke or basket) and the Sling Angle Deration both change the effective WLL, which is why a deration chart matters as much as the tag on the sling itself. Multi-leg chain slings connect to the crane hook via a Master Link at the top, and a Shortening Clutch lets a rigger take up slack in one leg on site rather than swapping the whole sling for a shorter one.
Read AIMS's full Chain Sling Guide → for grade markings, inspection intervals and rejection criteria
Shop AIMS's range of rigging and lifting slings →
What Is a Chamfer?
A chamfer is an angled edge cut onto a corner or hole entry — easing assembly, removing a sharp burr, or giving a component a defined, deliberate edge rather than a rough one. It's distinct from a Countersinking recess, which is specifically sized and angled to seat a particular fastener head rather than just breaking an edge. AIMS's own guide draws the practical line: hand deburring tools shear a general edge break with a pivoting blade, while a dedicated chamfer tool — a multi-flute rotary cutter run in a drill or press — mills a precisely defined angle (commonly 45°, 60°, 82° or 90°) for production-spec work. See Deburring below for the hand-tool side of that comparison.
Read AIMS's full Deburring Tool Guide → for chamfer tools vs deburring tools
Shop AIMS's range of corner chamfer end mills →
What Is a Changeover Switch?
A changeover switch is a manual or automatic switch that isolates a switchboard from the grid before a backup generator is connected, so the two power sources can never be live on the switchboard at the same time. This isolation step exists to prevent Backfeeding — generator power flowing back out into the street grid, which is a serious safety hazard for anyone working on what they assume is a de-energised line. An Automatic Transfer Switch (ATS) does the same job without operator intervention.
What Is a Check Valve? (Non-Return Valve / NRV)
A check valve — also called a non-return valve (NRV) — is a self-actuating one-way valve with no handle, lever or external actuator, designed purely to let flow pass in one direction and slam or ease shut the moment flow tries to reverse.
Six types dominate industrial supply, each suited to a different failure mode and installation: swing check valves (a single hinged disc, gravity-closed, horizontal orientation only, with a genuine slam risk); dual-plate (wafer) check valves (two spring-loaded half-discs, installable in any orientation, low slam risk, and now the default modern choice for most industrial pump-discharge applications); ball check valves (a free-rolling ball, ideal for sewage, slurry and solids-laden service since the smooth body sweeps debris through); lift check valves (a vertically-lifting disc, higher head loss, suited to small-bore high-pressure service); silent/nozzle check valves (spring-closed in as little as 0.05–0.1 seconds — fast enough to close before reverse flow even develops, at a genuine cost premium of 3–5× a dual-plate valve); and foot valves (an integrated strainer at a pump's suction line, holding the pump's prime when it stops). Correct sizing matters as much as correct type: a check valve should operate in the upper 50–75% of its rated flow range, since oversizing causes disc oscillation and premature wear. See Water Hammer for the specific failure this valve type exists to prevent, and why the wrong check valve for the application can make water hammer worse rather than better.
Read AIMS's full Check Valve Guide →
Shop AIMS's range of pipe fittings →
What Is a Chemical Anchor?
A chemical anchor is a fastening system that bonds a threaded rod, rebar dowel or stud into a hole drilled in concrete or masonry using a resin adhesive, rather than gripping the hole mechanically the way a Wedge Anchor or Drop-In Anchor does — the resin is dispensed from a glass capsule (spun in with a rotary hammer) or injected from a two-part cartridge through a static mixing nozzle, then cures around the fastener to form a solid chemical and mechanical bond to the substrate.
Because it bonds rather than expands, a chemical anchor doesn't impose the radial bursting stress an expansion anchor does — making it the right choice for anchoring close to an edge, into hollow brick or block, into cracked concrete, or wherever a heavier structural load needs to be carried than a mechanical anchor of the same diameter can manage. Selection comes down to resin chemistry (see Vinyl Ester Resin and Epoxy Resin below), correct Embedment Depth, and borehole cleaning — a poorly cleaned hole is the single most common cause of chemical anchor pull-out, regardless of how well the anchor itself was chosen. "Chemset®" is the genericised everyday name for this whole anchor category in Australian trade speech — see Chemset® below.
Read AIMS's full Chemical Anchor Guide → for resin chemistry, cure times, embedment tables and AS 5216 ETA options
Shop AIMS's range of masonry & concrete anchors →
What Is Chemset®? (Chemical Anchor)
Chemset® is the genericised everyday name Australian trade uses for chemical anchoring generally — it started life as Ramset's own branded chemical anchor product, the same way "Dynabolt" started as a specific Ramset trademark, and has since become the default word tradies reach for regardless of which brand's resin-injected anchor is actually on site.
Functionally, "doing a Chemset®" and installing a Chemical Anchor are the same job — see that entry above for how the resin bonding actually works, the choice between Vinyl Ester Resin and Epoxy Resin, and correct Embedment Depth. AIMS's own chemical anchor guide addresses this genericisation directly and supplies equivalent resin anchor systems — including Hobson stud kits and Epirez structural epoxy — rather than the Ramset-branded product itself.
Read AIMS's full Chemical Anchor Guide → for the resin systems AIMS actually stocks
What Is a Chipping Hammer?
A chipping hammer has a pointed and/or chisel-shaped head, purpose-built to remove weld slag and spatter after welding — striking along the weld bead knocks the brittle slag layer free without damaging the sound weld metal underneath.
Most chipping hammers pair a chisel-pointed head with a wire-brush handle or a separate wire brush, since slag removal and post-weld wire brushing are almost always done as one combined step — chip the slag off, then brush the bead clean before the next pass or before painting.
Read AIMS's full Hammer Types Guide →
What Is Chromoly? (Chromium-Molybdenum Steel)
Chromoly — short for chromium-molybdenum steel, most commonly the SAE 4130 alloy grade — is a low-alloy steel that achieves considerably higher strength than Mild Steel at a similar or lower weight, by adding small amounts of chromium and molybdenum rather than relying on carbon content alone.
That higher strength-to-weight ratio is exactly why chromoly shows up wherever a structure needs to be both strong and light: motorsport roll cages and chassis tubing, high-performance bicycle frames, and aircraft tube structures all specify it over mild steel for the same reason. It's more expensive and generally harder to weld than mild steel — chromoly usually needs TIG welding and, on thicker sections, post-weld heat treatment to avoid brittleness in the heat-affected zone — so it's specified deliberately for the weight saving rather than used as a general-purpose structural steel.
What Is a Chuck Key?
A chuck key is a small, geared key used to tighten or loosen a keyed drill chuck — inserted into one of the chuck body's geared holes and turned to open or close the jaws around a drill bit or other round-shank tool.
A keyed chuck needs its matching chuck key on hand every time a bit is changed — lose the key, and the chuck can't be opened without another tool entirely — which is exactly the inconvenience a keyless chuck (tightened and loosened by hand, no key required) exists to remove, at some cost in maximum clamping force versus a genuinely tight keyed chuck.
Shop AIMS's range of drill chucks — keyed & keyless →
What Is a Chucking Reamer?
A chucking reamer (machine reamer) is a reamer with a parallel round shank designed to fit a drill chuck, collet or Morse taper, run under power feed at production speed rather than turned by hand — AIMS's own guide describes it as the most widely used machine reamer in both home-workshop and small-engineering settings. Its short chamfer lead (compared with a hand reamer's long, self-aligning taper) suits a spindle-aligned setup where the machine itself keeps the reamer on centre, rather than relying on the operator's hand-feel to find true alignment. Governed in Australia and internationally by DIN 212 (H7 tolerance) and ISO 521.
Read AIMS's full Reamer Guide → for hand vs machine reamer selection and stock-removal allowances
Shop AIMS's range of reamers →
What Are Circlip Pliers?
Circlip pliers are a pair of pliers purpose-built to install and remove circlips (retaining rings) — but internal and external circlip pliers work in opposite directions and aren't interchangeable, so picking the wrong pair for the job simply won't fit the ring.
Internal circlip pliers spread their tips apart when squeezed, expanding a circlip seated inside a bore so it can be withdrawn or fitted; external circlip pliers do the opposite, squeezing their tips together to compress a circlip seated on a shaft. Some pliers are convertible between the two modes via a reversible tip pin, but a genuinely different pair for each job remains the more common and more robust setup for regular use.
Read AIMS's full Circlip Pliers Guide →
Shop AIMS's range of retaining ring pliers →
What Is a Circuit Breaker?
A circuit breaker is a re-settable electrical safety switch that automatically interrupts current flow when it detects an overload or short circuit, protecting the wiring and connected equipment from overheating or fire. Unlike a fuse, a circuit breaker doesn't need replacing after it trips — it can simply be reset once the fault is cleared.
There are two common families in AU industrial and commercial work: an MCB (Miniature Circuit Breaker) handles the lighter current ranges typical of a standard switchboard, while an MCCB (Moulded Case Circuit Breaker) steps up to higher current ratings and larger fault-breaking capacity for heavier industrial and commercial installations. Both are also classed by trip curve — Type B trips fastest (3–5× rated current), suited to resistive loads like lighting and general power outlets; Type C trips at a higher threshold (5–10×), suited to inductive loads like motors and transformers that draw a brief high inrush current on start-up; Type D trips highest again (10–20×), reserved for heavy inrush loads such as large transformers or welding equipment. Fitting the wrong trip curve is a common, avoidable cause of "nuisance tripping" on motor circuits — a Type B breaker on a motor circuit will often trip on ordinary start-up current that a Type C would ride through safely, which is exactly the kind of thing worth checking before assuming a starting method (see DOL (Direct-On-Line) Starting) is at fault. Note that a circuit breaker alone doesn't protect *people* from electric shock the way an RCD does — the two do different jobs and AU wiring rules generally require both on a modern switchboard, sometimes combined into a single RCBO device.
What Is CKD? (Completely Knocked-Down)
CKD stands for Completely Knocked-Down — equipment or vehicles shipped as a full set of unassembled parts and components, to be assembled entirely at the destination rather than arriving built.
It sits at the opposite end of the scale from CBU (Completely Built-Up), with SKD (Semi-Knocked-Down) as the middle ground. CKD shipping reduces freight volume (unassembled parts pack far more efficiently than a finished machine) and can attract lower import duty in markets that tax finished goods more heavily than components — but it requires a genuine local assembly capability, qualified labour and often manufacturer-supplied jigs or documentation to do properly.
What Is Clamp Force?
Clamp force (clamping force, joint clamp load) is the compressive squeezing force a tightened bolted joint exerts on the parts held between the bolt head (or nut) and the mating surface — the actual functional output of tightening a fastener, as distinct from Torque, which is simply the input used to try to achieve it.
Clamp force is what actually keeps a joint together and resists it working loose or separating under service load; torque is only a usable proxy for it once friction (see Frictional Coefficient and K-Factor / Nut Factor) is reasonably well controlled. Too little clamp force risks the joint loosening or separating in service; too much risks yielding the bolt (see Proof Load) or crushing softer clamped material. AIMS's own torque chart converts grade and size into an indicative torque value precisely because clamp force itself can't be read directly with a standard torque wrench.
Read AIMS's full Metric Bolt Torque Chart → for the torque-to-clamp-force relationship and the T = K × F × d formula
What Do Class 1A/1B, 2A/2B, 3A/3B Threads Mean?
Thread classes 1A/1B, 2A/2B and 3A/3B are the American (Unified) system for specifying how tightly an external thread ("A", on a bolt or screw) and an internal thread ("B", in a nut or tapped hole) are meant to fit together, under ANSI/ASME B1.1.
Class 1 gives the loosest fit, intended for fast assembly and disassembly even with dirt, minor damage or slight corrosion present — appropriate where speed and forgiveness matter more than precision. Class 2 is the commercial-grade default for the vast majority of bolts, screws and nuts in general industrial and commercial use, balancing straightforward assembly with reasonably controlled fit. Class 3 gives the tightest fit, specified where precision alignment and minimal play matter — aerospace, precision instruments and safety-critical fastening. This American system runs alongside, but is not directly interchangeable with, the metric tolerance-class system used on ISO threads. *(Independent standards source — ANSI/ASME B1.1 — no dedicated AIMS article detailing thread class fits specifically.)*
What Is Clay (Bentone) Grease?
Clay grease — also called Bentone grease after the clay mineral used as its thickener — is a non-soap thickener chemistry suited to high-temperature and food-processing applications, rated to around 150°C. Being a genuinely non-soap thickener (rather than a metallic soap like lithium or aluminium complex) gives it different compatibility characteristics from the other greases in this category — worth checking specifically rather than assuming it follows the same mixing rules as the soap-based thickeners (see Grease Compatibility).
Shop AIMS's range of greases →
What Is Clearance Fit?
A clearance fit is a mechanical fit between two mating parts — a bolt and a hole, a shaft and a bushing — deliberately sized so the two parts always have some gap between them, however they land within their respective tolerances, allowing free assembly and, where relevant, relative movement.
Clearance fit sits at one end of a spectrum that runs through transition fits (which may be a slight clearance or a slight interference depending on where each part lands within tolerance) to interference (press) fits, where the parts always overlap and have to be forced or thermally assembled together. For a bolted joint specifically, "clearance hole" sizing (the hole is deliberately larger than the bolt's major diameter) is what allows a Bearing-Type Joint or Friction Type Joint to be assembled by hand before tightening. *(General engineering fundamentals — no dedicated AIMS article for this term.)*
What Is a Cleat? (Conveyor Belt)
A cleat is a moulded rubber rib — commonly a chevron (V or herringbone) pattern — bonded across a conveyor belt's top Cover Compound (Conveyor Belt) at regular intervals, giving loose or granular material something to sit against so it doesn't roll back down the belt on an incline.
Cleated (chevron) belting is the standard fix for inclined conveyors carrying loose bulk material — sand, gravel, grain, coal — beyond the roughly 18–20° maximum incline a plain flat belt can hold material on before it starts sliding back. Cleat height and spacing are matched to the incline angle and the material's angle of repose, and because cleats are moulded into the belt's cover rather than bolted on as an accessory, a cleated belt generally can't run through standard scrapers or Skirting (Skirt Board, Conveyor) designed for a flat belt without those components being adapted to suit.
What Is a Closed-End Nutsert? (vs Open-End)
Open-end and closed-end describe whether a rivet nut's threaded bore is open all the way through the blind end or sealed off — open-end is the standard type, allowing a bolt to pass fully through and out the back; closed-end seals the blind side, blocking water, dust and other contaminants from entering through the back of the fastener.
Closed-end nutserts are specified wherever the back of the panel faces a wet, dusty or corrosive environment — marine equipment, outdoor enclosures, food-processing machinery — where an open bore would let contamination track straight through the panel. Beyond sealing, the two types install and perform identically. *(General fastening-industry terminology, cross-referenced against AIMS's own rivet nut guide.)*
Read AIMS's full Rivet Nut Guide → for open vs closed end selection and body type comparison
What Is a CMM (Coordinate Measuring Machine)?
A CMM (Coordinate Measuring Machine) is a precision metrology instrument that measures a workpiece's physical geometry by sampling points on its surface with a probe, then reports all of them against a single 3D reference frame — letting dozens of features be checked from one fixturing rather than measured individually with hand tools. International acceptance testing for a CMM is governed by ISO 10360, which sets a strict bar: 100% of measurement results must fall within the specified maximum permissible error (MPE) — a single outlier fails the test, a materially tighter requirement than a general accuracy claim on a spec sheet. Common configurations include bridge (the standard workshop QC tier for production and automotive parts), gantry (large parts, 3–8m and up, aerospace and rail), cantilever (easy load/unload from three sides on the shop floor) and portable arm (on-site measurement where the part can't be moved, typically accurate to ±20–80 microns). Every published CMM accuracy spec assumes a controlled 20°C ±1°C environment with no vibration — real workshop-floor performance is commonly five to ten times worse than the spec sheet when those conditions aren't met, which is worth knowing before comparing two suppliers' numbers at face value.
Read AIMS's full Coordinate Measuring Machine Guide → for CMM types and the ISO 10360 accuracy formula
What Is CNC?
CNC (Computer Numerical Control) describes a machine tool — a lathe, mill or drilling machine — controlled by a pre-programmed sequence of coded instructions rather than a human operator manually turning handwheels for every cut. A CNC machine still performs the same fundamental operations as its manually-operated equivalent (see Lathe below), but repeats them with a precision and consistency across hundreds or thousands of parts that manual operation can't reliably match — the trade-off being the upfront cost of programming and machine setup, which only pays off at meaningful production volume. *(General engineering fundamentals — no single dedicated AIMS article for this term as a stand-alone concept.)*
What Is Coarse Thread?
Coarse thread refers to a component's standard, larger-pitch thread option at a given nominal diameter — coarse pitch is the default spacing (between adjacent threads) for that size, as opposed to the tighter spacing of a Fine Thread at the same diameter.
Coarse threads assemble faster, resist cross-threading and stripping better, and tolerate dirt, paint and minor damage more forgivingly — the sensible default for most general fastening.
Read AIMS's full Metric vs Imperial Fasteners Guide → for coarse/fine pitch comparisons across metric and imperial systems
What Is Coating (Fastener)?
A coating, in the fastener sense, is any layer applied to a fastener's surface to change its corrosion resistance, friction, appearance or thread fit relative to bare steel — Zinc Plating, Hot Dip Galvanizing, Dichromate and Electroplating are all specific coating processes covered in their own entries below. Coating choice genuinely changes a fastener's dimensions and thread fit (a hot-dip-galvanised nut is tapped oversize to compensate for coating thickness) and its corrosion life (measured, in AIMS's own guide, in salt-spray-test hours before red rust appears) — not just its colour, which is why matching the right coating to the right environment matters more than picking whichever one happens to be in stock.
Read AIMS's full Zinc Plated vs Galvanised vs Stainless: Bolt Coatings Guide →
What Is a Cogged / Notched Belt?
A cogged (or notched) belt has moulded notches across its underside to increase flexibility around small-diameter pulleys and improve heat dissipation, while still running on ordinary plain V-pulleys rather than requiring toothed sheaves.
This is the key distinction from a Synchronous (Timing) Belt: a cogged belt still transmits power through friction and wedging like any other V-belt — the notches just make it bend more easily — whereas a timing belt's teeth engage matching sheave teeth for genuine positive, no-slip drive. A cogged V-belt is identified by an "X" prefix on its part number (e.g. "XB68"), and is covered in more construction detail under Raw-Edge / Cogged V-Belt.
Read AIMS's full Belt vs Chain Drives Guide →
Shop AIMS's range of industrial drive & conveyor belts →
What Is a Cold Chisel?
A cold chisel is a hand chisel made of hardened, tempered steel, struck with a hammer to cut, shear or shape cold metal — "cold" distinguishing it from a blacksmith's hot chisel, which is used on metal heated soft in a forge.
Common uses include shearing off a rusted or rounded nut head, cutting a sheet-metal edge, chipping out old weld or rivet heads, and general demolition-adjacent metalwork where a powered cutting tool isn't practical or available. See Chisel Guide for how a cold chisel compares to the SDS and masonry chisel types used for concrete and brick rather than metal.
Read AIMS's full Chisel Guide →
Shop AIMS's range of chisels and files & chisels →
What Is Cold Working?
Cold working (also called cold forming) is shaping or forming metal at room temperature — rolling, drawing, bending or stamping — rather than heating it first. It increases strength and hardness compared with the same material in its original state, but at the cost of some ductility.
Cold-drawn steel bar, for example, is stronger and has a better surface finish than hot-rolled bar of the same grade, which is why it's often specified for precision shafts and pins. The trade-off is that cold-worked material carries internal stress that annealing or Stress Relieving can remove if needed before further machining.
What Is Colorbond®?
Colorbond® is BlueScope's registered trademark for pre-painted, colour-coated steel — one of the most recognised building products in Australia, used across roofing, wall cladding, fencing, garage doors, sheds, gutters and fascia.
The steel underneath the paint is the same aluminium/zinc/magnesium alloy metallic coating BlueScope sells bare as Zincalume; Colorbond® takes that coated substrate and adds a baked-on paint finish over the top for colour, UV resistance and extra corrosion protection. It's manufactured to the AS 1397 steel-substrate standard and the AS/NZS 2728 paint-coating standard. The standard range spans dozens of colours across Classic, Matt and Metallic finishes, alongside higher-spec variants for tougher applications — COLORBOND® Ultra steel (aggressive and coastal environments), COLORBOND® Coolmax® steel (heat-reflective, for insulated roofing) and COLORBOND® Intramax® steel (for exposed structural sections like purlins and girts) — each backed by a longer warranty than the standard range.
While AIMS doesn't supply Colorbond® sheet itself, it's a common substrate for AIMS's own anti-slip products — stair nosing and tread products are frequently supplied for direct application to Colorbond® steps, platforms and walkways. See AS 4586 for the slip-resistance rating those products are tested and specified against. The Colorbond® colour range has also become a de facto standard for painting and touching up steel more broadly across Australian trade and construction work, and AIMS stocks paint matched to the Colorbond® colour range for exactly that purpose.
Shop AIMS's range of antislip safety solutions →
Shop AIMS's range of Colorbond paint colours →
What Are Combination Pliers?
Combination pliers are the general-purpose pliers found in almost every toolbox — flat gripping jaws near the pivot for holding flat or round stock, and a cutting edge further back for snipping wire, combining two functions a dedicated gripping or cutting tool would otherwise split apart.
They're the default choice for general electrical, automotive and workshop tasks precisely because they cover both gripping and light cutting without a tool change — but for genuinely fine work (Needle Nose Pliers) or dedicated wire cutting (Side Cutters), a purpose-built tool still outperforms the general-purpose combination pliers on that one task.
Read AIMS's full Types of Pliers Guide →
Shop AIMS's range of mixed plier sets →
What Is a Combination Square?
A combination square is a multi-function marking-out tool — a sliding head on a graduated rule that combines a 90° square, a 45° mitre reference and, on most models, a level vial and depth/height gauge in one instrument. It trades a small amount of accuracy against a fixed Engineer's Square for versatility — one tool doing several jobs makes it the practical choice for general marking-out, multi-angle work and depth checks, where a dedicated engineer's square remains the more accurate reference for verifying true squareness. See Engineer's Square and Steel Rule below for the other two tools in this everyday workshop trio.
Read AIMS's full Engineers Square, Combination Square & Steel Rule Guide → for accuracy grades and selection
Shop AIMS's range of combination squares →
What Is a Come-Along (Cable Puller)?
A come-along (cable puller) is a manually operated ratchet tool that pulls a wire rope or webbing strap through a fixed anchor point to tension, position or drag a load horizontally — the rigging equivalent of a winch, but portable and needing no power source. It's the standard fix for pulling fencing wire tight, aligning machinery on a base, or dragging a stuck vehicle a short distance, and is distinct from a Drum Winch, which spools the full length of cable onto a drum rather than incrementally ratcheting it through.
Read AIMS's full Come-Along & Winch Guide → for pull ratings and rope vs strap selection
Shop AIMS's range of cable pullers and winch accessories →
What Are Composite Toe Boots?
Composite toe boots are Safety Footwear fitted with a non-metallic (composite) toecap, certified in Australia under AS/NZS 2210.3 to the same 200-joule impact and 15 kN static compressive load threshold as Steel Cap Boots.
Composite toecaps are non-conductive, lighter and don't transmit cold in refrigerated environments, but they need more physical bulk to meet the same rating, cost 20–40% more, and have lower crush resistance under sustained compressive load than steel — they're not simply an equivalent, lighter version of a steel cap.
Read AIMS's full Steel Cap Boots Guide →
Shop AIMS's range of safety footwear →
What Is a Compression Fitting?
A compression fitting joins two lengths of pipe or tube without welding, soldering or gluing — a nut threads over the pipe and compresses a ferrule (also called an olive) against both the pipe's outer surface and a matching seat inside the fitting body, creating a mechanical seal purely through that compression.
Two ferrule styles cover most applications: a single-ferrule fitting for lower-pressure water, gas and pneumatic lines, and a two-ferrule (front and back ferrule) design for higher-pressure instrumentation and hydraulic tubing, where the extra ferrule gives a more reliable bite and better resistance to vibration loosening. Compression fittings are reusable — unlike a soldered or welded joint, a compression fitting can be disassembled and reassembled on the same tube — which is exactly why they're the default choice for domestic and light commercial copper and polyethylene pipe work where a plumber needs to make a quick, tool-only joint without a torch. Getting the pipe end cut square and deburred before assembly matters as much as the tightening torque itself: an out-of-round or burred pipe end is a common cause of a compression joint that leaks on first pressure test. See BSP, NPT and BSPT / BSPP for the thread standards a compression fitting's own body connection is typically cut to.
What Is a Concrete Anchor?
A concrete anchor is the umbrella term for any fastener designed to anchor a fixture, plant or structural element into concrete or masonry — covering two fundamentally different mechanisms: mechanical anchors, which grip the hole by expansion, friction or a self-cut thread, and chemical anchors, which bond into the hole with resin adhesive.
Within the mechanical family alone, Australian trade uses several distinct product types that get confused with each other constantly: a Wedge Anchor expands a cone or sleeve against the hole wall as its nut is tightened, a Drop-In Anchor expands flush and internally threaded for a bolt to be driven in later, and a masonry screw simply cuts its own thread with no expansion at all — Ramset's own trademarked product lines across this category, Dynabolt®, Trubolt® and Ankascrew®, are each covered as their own entry below rather than treated as interchangeable names for the same thing. Design and qualification of post-installed concrete anchors in Australia sits under AS 5216, which rates every anchor type here for cracked vs uncracked concrete and seismic performance.
Read AIMS's full Concrete Anchor Guide → for the full wedge, sleeve, drop-in, chemical and masonry screw comparison
Shop AIMS's range of masonry & concrete anchors → and stud anchors →
What Is Confined Space Entry?
Confined space entry is work carried out inside a space that isn't designed for continuous occupancy, has limited entry or exit, and carries the risk of an unsafe oxygen level, hazardous atmosphere, or engulfment — tanks, pits, silos, pipes and similar enclosed structures all typically qualify, and entry requires its own permit and rescue plan under Australian WHS law before anyone goes in.
A confined space entry kit typically combines a tripod (rated for the retrieval load, positioned over the entry point), a personnel winch or Inertia Reel for controlled lowering and raising, harnesses for anyone entering, and a spreader bar to manage the retrieval geometry — the point of the kit is to let a crew retrieve a worker quickly without anyone else having to enter the space themselves.
Shop AIMS's range of confined space equipment →
What Is Constant Pitch?
A constant-pitch thread is one where the pitch stays the same across a whole range of diameters, rather than changing (as coarse-series threads normally do) as the diameter increases — used where a specific pitch needs to be held for a particular engineering reason regardless of the nominal size.
Constant-pitch series are specified in applications like large-diameter fine adjustment mechanisms, certain hydraulic and instrumentation fittings, and situations requiring interchangeability of pitch across a family of different-diameter parts. This is the same underlying concept as Thread Pitch — spacing between adjacent thread crests — applied as a deliberately fixed value rather than one that scales with diameter. *(General engineering fundamentals — no dedicated AIMS article for this term.)*
What Is a Construction Adhesive?
Construction adhesive is a high-strength, gap-filling adhesive designed for structural and semi-structural bonding in building and construction work — panelling, skirting, decking and general building assembly — typically applied from a caulking gun in a bead, similar to Caulk, but formulated for load-bearing strength rather than flexible sealing.
It tolerates larger, more irregular joint gaps than a contact adhesive would, and is generally chosen over mechanical fixing where a clean, fastener-free finish matters or where the substrate can't easily take screws or nails.
Read AIMS's full Industrial Adhesive Types Guide →
Shop AIMS's range of adhesives, sealants & tapes →
What Is a Contact Adhesive?
Contact adhesive is a solvent-based adhesive that cures by solvent evaporation, forming a tacky surface on both parts that bonds strongly the moment they're pressed together — the joint needs to be positioned correctly on first contact, since there's little to no repositioning once the surfaces touch.
It's one of the most widely used adhesives in Australian industry for large-area bonds on flexible substrates — rubber lining, foam gaskets, leather and canvas — with a working range of about -30°C to +80°C and a 15–20 minute tack-off period before the two surfaces are pressed together.
Read AIMS's full Industrial Adhesive Types Guide →
Shop AIMS's range of adhesives, sealants & tapes →
What Is a Converter Dolly?
A converter dolly is a short, wheeled unit — typically one or two axles — carrying its own Turntable (fifth-wheel-style coupling), used to convert a semi-trailer into the rear trailer of a longer combination such as a road train or an A-double. The dolly couples to the drawbar of the lead unit at one end and takes a semi-trailer's kingpin at the other, effectively giving a trailer designed to sit on a prime mover's fifth wheel a "second fifth wheel" of its own further back in the combination.
What Is a Core Drill (Core Bit)?
A core drill (core bit) is a hollow-shanked drilling tool that cuts only an annular groove around a hole's circumference, rather than removing the full hole's cross-section as a solid twist drill would — leaving a solid cylindrical core (or slug) behind. It's used specifically for large-diameter holes, where full-face drilling with a twist drill would demand far more machine power and torque than the job realistically has available. In AIMS's own metalworking range, this same working principle is what an Annular Cutter is — the generic "core drill/core bit" name and the branded "annular cutter" name describe the same underlying tool family, with annular cutter the term used more specifically in the mag-drill and structural-steel context.
Read AIMS's full Annular Cutter Guide → for sizing and the same working principle under its AIMS product name
Shop AIMS's range of annular cutters & sets →
What Is Corrosion Cracking, Stress?
Stress corrosion cracking is the combined failure of sustained tensile stress and a corrosive environment acting together on a susceptible metal — producing cracks that neither the stress nor the corrosion alone would cause, and often with little visible surface corrosion to warn that it's happening. It's the same family of failure as Hydrogen Embrittlement (covered in Fasteners & Threading) in that both produce a fastener or component that looks sound but fails suddenly under load, well below its rated strength, which is why both are treated as serious enough to specify against rather than just inspect for after the fact.
This entry is written to established corrosion-science fundamentals rather than an AIMS source.
What Is Corrosion, Chemical Attack?
Chemical attack corrosion is direct chemical reaction between a metal and an aggressive substance it's exposed to — an acid, a strong alkali (see Alkaline), or a specific chemical the metal simply isn't compatible with — as distinct from the electrochemical, cell-based mechanisms covered in Corrosion, Electrochemical, Corrosion, Galvanic and Corrosion, Concentration-cell below. The practical takeaway for fastener and equipment selection is compatibility: the right coating or material choice depends on knowing exactly what chemical environment a component will actually see in service, not just whether it will get wet.
This entry is written to established corrosion-science fundamentals rather than an AIMS source.
What Is Corrosion, Concentration-cell?
Concentration-cell corrosion happens when two areas of the same metal are exposed to different concentrations of oxygen or dissolved ions — commonly under a gasket, washer, deposit or crevice where oxygen can't circulate as freely as it does on the surrounding exposed surface. The oxygen-starved area becomes anodic (see Anode / Cathode) relative to the oxygen-rich area and corrodes preferentially, which is why crevice corrosion under washers and gaskets is a genuinely distinct failure mode from general surface corrosion, not just a variation of it.
This entry is written to established corrosion-science fundamentals rather than an AIMS source.
What Is Corrosion, Electrochemical?
Electrochemical corrosion is the general category that Corrosion, Galvanic and Corrosion, Concentration-cell both belong to: any corrosion process driven by an electric current flowing between an Anode / Cathode pair through an electrolyte (moisture, salt water), rather than by direct chemical reaction alone. It's the dominant corrosion mechanism for metals in outdoor and marine environments specifically, which is why coating and material selection for those environments focuses so heavily on managing galvanic pairing and moisture exclusion rather than chemical resistance alone.
This entry is written to established corrosion-science fundamentals rather than an AIMS source.
What Is Corrosion, Galvanic?
Galvanic corrosion happens when two dissimilar metals are in electrical contact in the presence of an electrolyte, and the less noble (more anodic) metal corrodes faster than it would on its own, while the more noble (cathodic) metal is protected — the same Anode / Cathode mechanism a sacrificial zinc coating deliberately exploits, but here it's an unintended failure rather than a designed protection. AIMS's own guide gives the practical warning for fastener selection: a small anodic fastener against a large cathodic structure is high-risk, since the corrosion current concentrates onto that small anode's surface area — a small zinc-plated bolt holding a large stainless structure together can corrode through surprisingly fast, exactly the pairing to avoid.
Read AIMS's full Zinc Plated vs Galvanised vs Stainless: Bolt Coatings Guide →
What Is Corrosion, Pitting?
Pitting corrosion is highly localised attack that eats small, deep holes into a metal surface rather than corroding evenly across it — often starting at a coating defect, an inclusion in the metal, or a chloride-rich environment such as a marine or coastal site. It's a particularly deceptive failure mode for fasteners and structural components because the surface can look largely intact while a pit has already eaten deep enough to seriously weaken the section — a genuine reason A4-316 stainless (rated for marine and coastal environments in AIMS's own coating guide) is specified over A2-304 in chloride-heavy sites, since 316's molybdenum content specifically improves pitting resistance.
This entry is written to established corrosion-science fundamentals rather than an AIMS source.
What Is a Cotter Pin (Split Pin)?
A cotter pin (split pin — the same fastener, the term varying by region: "split pin" in Australia and the UK, "cotter pin" in the US) is a folded-wire fastener with two prongs that pass through a drilled hole and are bent apart to lock an assembly in place — a retention-only fastener, never load-bearing in its own right.
Cotter pins are most safety-critical when paired with a Castle Nut — AIMS's own guide is unambiguous that a castle nut without its cotter pin fitted provides no lock at all, and that the pin must never be reused, since bending work-hardens the wire and makes a second bend significantly more likely to crack. Sizing follows DIN 94 / ISO 1234, with the pin diameter chosen roughly 0.1–0.4 mm smaller than the hole for a snug, non-sloppy fit.
Read AIMS's full Split Pin & Cotter Pin Guide → for DIN 94 sizing and correct two-direction bend installation
Shop AIMS's range of cotter pins & split pins →
What Is a Counterbore?
A counterbore is a cylindrical, flat-bottomed recess machined concentric to an existing hole, letting a fastener with a flat-bottomed, cylindrical head — a socket head cap screw, button head socket screw, or a hex bolt head that needs to be recessed — sit flush with or below the surrounding surface. It's distinct from Countersinking, which cuts a tapered conical recess instead: the fastener head's own geometry decides which tool is correct, and using the wrong one leaves a gap that stops the fastener seating properly and concentrates stress on it under load rather than spreading it across the full recess.
Read AIMS's full Counterbore Drill Bits Guide → for sizing and the full counterbore-vs-countersink comparison
Shop AIMS's range of counterbores →
What Is Countersinking?
Countersinking cuts a tapered, conical recess at the entry of a hole, matching the angled underside of a flat-head screw so the fastener draws flush with, or slightly below, the surrounding surface as it's tightened. The included angle has to match the fastener standard being used — 90° is standard for metric flat-head screws (ISO 7046 / DIN 965), while 82° is the imperial equivalent used on UNC/UNF flat-head screws, with 60° and 120° also turning up for specific fastener families. See Counterbore above for the flat-bottomed cylindrical recess used instead, whenever the fastener head itself is cylindrical rather than conical.
Read AIMS's full Counterbore Drill Bits Guide → for countersink angles by fastener standard
Shop AIMS's range of countersink bit sets →
What Is a Countersunk Head?
A countersunk head has a conical underside that tapers to match a correspondingly angled (countersunk) hole, letting the fastener sit completely flush with, or even below, the surrounding surface — standard wherever a proud head would be a snag hazard or interfere with a mating flat surface.
The angle matters and isn't universal: Australian metric practice uses a 90° included angle, while the North American imperial standard uses 82° — mixing the two causes the head to seat incorrectly, either standing slightly proud or bedding in too deep and stressing the material around the hole. Countersunk screws are standard for hinges, guards, structural steel connections and anywhere a flush finish or snag-free surface is required.
Read AIMS's full Countersunk Screw Guide → for CSK angles, sizes and countersink-vs-counterbore comparison
Shop AIMS's range of countersunk screws →
What Is Cover Compound? (Conveyor Belt)
Cover compound is the rubber (or PVC/PU on lightweight belting) layer bonded to both faces of a belt's Carcass (Conveyor Belt) — the top cover takes the impact and abrasion of material loading and cargo contact, while the thinner bottom cover runs against pulleys and idlers. It's a wear layer, not a strength layer: the covers contribute only minimally to a belt's tensile rating, which comes almost entirely from the carcass underneath.
Cover compounds are graded to the failure mode they're actually expected to face, not just the general cargo type — ISO 10247 defines grades such as D (heavy abrasion resistance), H (cut and gouge resistance under high tension/elongation) and L (general purpose), alongside specialty grades for oil and grease exposure (G), elevated-temperature service (T1/T2/T3) and flame/anti-static ratings for underground or dust-explosive environments. That last category overlaps with FRAS (Flame Resistant Anti-Static) in the Belts & Drives category — a belt's cover compound is where that certification actually lives. Getting the compound wrong is a genuine failure mode in its own right: a heat-resistant carcass paired with a general-purpose cover will still harden and crack at a hot loading point, and an abrasion-grade cover in an oily application will swell and debond regardless of how strong the carcass underneath is.
What Is CRC? (Corrosion Resistant Coating)
CRC, in a fastener and coatings context, stands for corrosion resistant coating — a general term for any of the protective coatings covered in this category (Zinc Plating, Hot Dip Galvanizing, Dichromate and so on), rather than one specific process. It's worth noting CRC is also a well-known Australian lubricants and chemicals brand name (CRC Industries) stocked throughout AIMS's own range — context makes clear which sense is meant, but it's genuinely two different things sharing an acronym.
What Is Creep (Materials)?
Creep is the slow, time-dependent permanent deformation of a material under a sustained load held well below its normal yield strength — deformation that keeps accumulating the longer the load is applied, rather than happening all at once. It becomes a genuine design concern at elevated temperature — broadly above 30–40% of a metal's melting point on the absolute (Kelvin) scale — which is why creep is a headline concern for boiler pipework, turbine blades and furnace components, but rarely a practical factor for ordinary fasteners and brackets running at room temperature. Creep progresses through three recognised stages — primary (the rate slows), secondary (a steady minimum rate) and tertiary (the rate accelerates toward failure) — and genuinely creep-prone components are designed against a maximum allowable creep rate or rupture life, not against yield strength alone. *(General engineering fundamentals — no dedicated AIMS article for this term.)*
What Is a Crescent Wrench? (Adjustable Wrench)
A crescent wrench — more properly an adjustable wrench or adjustable spanner — is a single tool with a screw-adjustable jaw that fits a range of fastener sizes, rather than the one fixed size a standard Spanner covers.
"Crescent" is a trade name after the Crescent Tool Company (Jamestown, NY, established in the early 1900s), one of the earliest and best-known American makers — now one of several brands, though "crescent" and "shifter" both remain everyday AU/US generic names for the tool regardless of brand. An adjustable wrench trades some precision for range: its jaw has more play than a correctly-sized fixed spanner, so a fixed spanner or socket is the better choice wherever one is available and rounding the fastener's corners is a real risk.
Shop AIMS's range of Bahco hand tools & adjustable wrenches →
What Are Crest, Root and Flank (Thread Anatomy)?
Crest, root and flank are the three basic geometric features that make up a single thread turn: the crest is the outermost point (the peak, on an external thread; the equivalent point at the bottom, on an internal thread), the root is the bottom of the groove between two adjacent threads, and the flank is the straight, angled surface connecting crest to root on each side.
These three features together define the thread's profile shape and, combined with the flank angle (60° for metric ISO and UNC/UNF threads; 55° for the older BSW/BSF Whitworth-form threads), determine how two mating threads actually bear against each other. Root also means something different in welding — a weld root is an entirely different feature in a different trade, worth keeping distinct from a thread root. *(General engineering fundamentals — no dedicated AIMS article for this term.)*
What Is a Crimped Wire Brush?
A crimped wire brush uses individual straight (crimped, not twisted) wires, giving a gentler, more flexible brushing action suited to general cleaning, light rust removal and surface finishing where a Knotted Wire Brush would be too harsh. See Wire Brush Fill Material below for how the wire material itself is chosen alongside this construction choice.
What Is a Cup Washer?
A cup washer is a shallow, dished (slightly concave) washer that seats a countersunk or oval-head fastener cleanly against a flat surface, or that caps and protects the end of a coach bolt's square-neck fixing — giving a neater, more finished appearance than a flat washer under a shaped fastener head.
Cup washers are most commonly seen paired with decorative or furniture-grade fixings (coach bolts on outdoor furniture and playground equipment being a classic example) where the dished shape both seats the fastener correctly and presents a tidier finished face than a plain flat washer would. *(General fastening-industry terminology — no dedicated AIMS article specifically on cup washers, though they sit within AIMS's broader washer range.)*
Shop AIMS's range of washers →
What Is Curing? (Adhesive)
Curing is the chemical process by which a liquid or paste adhesive or sealant transforms into its final solid, bonded state — through solvent evaporation, moisture exposure, chemical reaction between two parts, or (for anaerobic products) the absence of oxygen against a metal surface.
Different adhesive chemistries cure by completely different mechanisms and at very different speeds — see Moisture Cure and Anaerobic Cure for how two of the most common mechanisms differ, and Fixture Time and Full Cure Time for how that plays out in practice. Curing conditions (temperature, humidity, substrate) can significantly speed up or slow down how long a product takes to reach handling or full strength.
Read AIMS's full Industrial Adhesive Types Guide →
What Is a Cut Thread?
A cut thread is formed by removing material with a cutting tool (a die, a single-point lathe tool, or a thread mill) to machine the thread profile into the rod or bolt blank, as opposed to a Rolled Thread, which forms the same profile by displacing material under pressure rather than cutting it away.
Cutting remains the practical choice for one-off or low-volume work (threading Allthread to length on-site, repairing damaged threads, or producing very large or very hard threads that rolling dies can't form), where AIMS's own tap-and-die range is the relevant tooling.
Read AIMS's full Tap & Die Guide → for cutting technique, lubrication and drill sizing
Shop AIMS's range of tap & die sets →
What Is Cut-In / Cut-Out Pressure?
Cut-in and cut-out pressure are the two tank-pressure setpoints on a piston compressor's pressure switch: cut-out is the pressure at which the switch stops the motor because the tank is full, and cut-in is the lower pressure at which it starts the motor again once tank pressure has dropped from use. Single-stage compressors typically cut out around 800–1,000 kPa (116–145 psi); two-stage units run higher, cutting out around 1,200–1,400 kPa (175 psi) — both comfortably above the roughly 620 kPa (90 psi) most pneumatic hand tools are designed to run at, leaving margin before the regulator.
This cycling behaviour is specific to a Piston Compressor (Reciprocating); a rotary screw compressor uses different control logic entirely (load/unload valving or variable-speed drive modulation) because it's designed to run continuously rather than switch on and off. The Receiver Tank is what the cut-in/cut-out differential is actually managing — a bigger gap between the two settings means longer runs between motor starts, at the cost of a wider working-pressure swing downstream.
Read AIMS's full Air Compressor Guide → for typical cut-in/cut-out figures by compressor stage
What Is a Cutting Disc?
A cutting disc is a thin (1.0–3.0mm) bonded abrasive disc built specifically for parting cuts — pushed straight through the work, never sideways, since side pressure can shatter it. It's easy to confuse with a Grinding Disc or a Flap Disc, but the three aren't interchangeable: a cutting disc is rated for one job only, and Australian WorkSafe guidance specifically warns against using one for grinding.
Read AIMS's full Cutting Disc Guide → for material, disc diameter and application selection
What Is Cyanoacrylate? (Super Glue / Instant Adhesive)
Cyanoacrylate (CA) — commonly known as super glue or instant adhesive — is a fast-curing adhesive that polymerises almost instantly on contact with the trace surface moisture present on most materials, giving fixture times as short as 10–30 seconds on rigid substrates.
Industrial-grade cyanoacrylate delivers significantly better moisture and temperature resistance than consumer-grade super glue, though it remains brittle under impact and has limited peel resistance — it's a strong, rigid bond rather than a flexible or shock-absorbing one, with a continuous service temperature limit of around 80°C. See Gap-Filling Adhesive (Gel) for the thickened gel variant used on vertical joints and porous materials where standard liquid CA would run.
Read AIMS's full Industrial Adhesive Types Guide →
Shop AIMS's range of adhesives, sealants & tapes →
What Is a Cylindrical Roller Bearing?
A cylindrical roller bearing uses straight rollers in line contact with the race, giving high radial load capacity from a compact section. The standard types — NU and N designations — carry essentially no axial load; flanged variants (NJ, NF, NUP) add limited axial capacity where a small amount of location is needed alongside the radial load.
Read AIMS's full Rolling Bearings: Types, Selection, Fitting & Failure Guide →
Shop AIMS's range of cylindrical roller bearings →
D
What Is a D-Shackle (Chain Shackle)?
A D-shackle (chain shackle) is a shackle with a straight-sided body, rated for in-line pulls only — unlike the rounded Bow Shackle, it isn't rated for side-loaded or multi-leg lifts, and using one that way can bend the shackle or drop the load. It's the standard choice wherever the pull is genuinely straight, such as terminating a single-leg wire rope or chain sling.
Read AIMS's full Bow Shackle & D-Shackle Guide → for WLL tables by pin size and grade
Shop AIMS's range of shackles →
What Is Datum Length? (Belt Measurement)
Datum length is the reference length a V-belt's size designation is measured against, and it's the standard modern belts are ordered and cross-referenced by — an SPA-profile belt numbered "SPA1600," for example, has a 1,600 mm datum length.
This is the same measurement covered as "Ld" under Belt Length Notation (La/Le/Ld/Lp/Lw/Li) — datum length has replaced the older "pitch length" terminology as the industry standard, because it's measured consistently at the belt's neutral cord axis rather than depending on how a particular belt's outer profile happens to sit.
Read AIMS's full Belt Length Acronyms Guide and V-Belt Sizing & Identification Guide →
What Is DCEP / DCEN? (Welding Polarity)
DCEP (Direct Current Electrode Positive) and DCEN (Direct Current Electrode Negative) describe which way current flows through a DC arc-welding circuit — DCEP has the electrode wired to the positive terminal and the work clamp to negative; DCEN reverses it. This single setting has a major effect on how heat is distributed between the electrode and the base metal, and getting it wrong is one of the most common — and most avoidable — causes of a poor weld.
DCEP concentrates more heat into the workpiece, giving deeper penetration, and is the standard setting for gas MIG (Welding) and for stick electrodes like E7018 and E6010 (see SMAW Electrode Classification). DCEN puts more heat into the electrode itself, giving faster fill with shallower penetration — it's what gasless flux-cored MIG wire needs, and what electrodes like E6013 and E7024 are designed to run on. TIG (Welding), by contrast, runs DCEN on steel and stainless (about two-thirds of arc heat lands on the base metal) and switches to AC entirely for aluminium and magnesium. Running an electrode or wire type on the wrong polarity produces a cold, porous, spatter-heavy weld even when every other setting is correct.
Read AIMS's full MIG Welding Guide and Stick Welding Guide →
What Is a Dead Blow Hammer?
A dead blow hammer has a hollow head filled with sand or steel shot, which shifts on impact to absorb the striking energy rather than letting it bounce back — delivering a solid, controlled blow with none of the rebound a solid-head hammer gives.
That "dead" strike (no bounce-back) makes it the preferred choice wherever a controlled, non-marring blow matters more than raw striking force — freeing a stuck bearing or gear without the risk of an uncontrolled rebound strike, or working on assemblies where a bouncing hammer head could damage an adjacent surface.
Read AIMS's full Hammer Types Guide →
Shop AIMS's range of dead blow hammers →
What Is Dead Centre? (Machining)
In machining, a dead centre is the non-rotating centre point fitted into a lathe's tailstock (and sometimes headstock) to support the far end of a workpiece between centres — "dead" because, unlike a live centre, it doesn't spin with the work.
Because a dead centre doesn't rotate with the workpiece, it generates friction at the point of contact and needs lubrication (typically a centre grease or anti-seize compound) to stop it galling or burning the work at higher speeds — this is exactly why live centres, which spin on their own bearing and eliminate that friction, are now the more common choice for anything but light, slow-speed turning. Don't confuse this trade meaning with the everyday, non-technical sense of "dead centre" (simply the exact middle of something) — in a machine shop, the term specifically means this tailstock fitting.
What Is Deburring?
Deburring is the process of removing the sharp, raised edges ("burrs") that drilling, milling, sawing or cutting leave behind on metal — edges that are hazardous to handle, reject paint and coatings, and concentrate stress at exactly the wrong point on a finished part. AIMS's own guide describes the workshop-standard tool as a hardened steel blade pivoting on a shank inside an ergonomic handle: as the operator pulls the tool along an edge, the blade rotates to follow the workpiece geometry and shears the burr off in a single pass, working equally on external edges, internal holes and slots. Blade choice matters by material and duty — a slim blade for sheet metal, a heavy-duty 3.2mm blade for solid steel and plate, and a tungsten carbide blade for hardened steel above roughly 55 HRC. The most important safety rule in the guide: never resharpen a deburring blade — resharpening weakens the blade's hook structure, and a snapped blade under load becomes a genuine laceration hazard.
Read AIMS's full Deburring Tool Guide → for blade selection, technique and the critical safety notes
Shop AIMS's range of deburring tools →
What Is a Deep Groove Ball Bearing?
A deep groove ball bearing is the most common bearing in industrial use — a single row of balls running in deep-grooved inner and outer races, carrying radial load plus moderate load in both axial directions. AIMS's own guide names the two standard series by bore-to-width proportion: the 6200 series is the slimmer "light" series for a given bore, while the 6300 "medium" series carries roughly 50% more radial load at the same bore size, at the cost of a larger outside diameter.
It's supplied open (no seal, external lubrication required), shielded (Bearing Seal Code ZZ — metal shields, low friction), or sealed (2RS — rubber contact seals, full grease retention for life). Electric motor bearings almost universally specify C3/C4 Internal Clearance rather than standard clearance, since the motor's own running heat would otherwise preload a standard-clearance bearing as the inner ring expands.
Read AIMS's full Deep Groove Ball Bearing Guide: 6200/6300, Seals & Brands →
Shop AIMS's range of deep groove bearings →
What Is a Deflection Pulley (Direction-Change Rigging)?
A deflection pulley is a fixed pulley used purely to redirect a wire rope or cable's line of pull around an obstruction or into a more convenient angle, without providing any mechanical advantage of its own. It's the rigging equivalent of a Snatch Block used in a fixed rather than travelling role — useful for routing a winch line around a corner, but every direction change through a deflection pulley adds friction load and a compounding angle that needs to be accounted for in the overall rigging plan, not just the final pull.
What Is a Degreaser?
A degreaser is a chemical cleaner formulated to dissolve and remove grease, oil and grime from parts and surfaces before further work — painting, welding, inspection or reassembly — as distinct from Penetrating Oil, which is formulated to free a seized joint rather than clean a surface. Choosing between a degreaser and Isopropyl Alcohol (IPA) generally comes down to how heavy the contamination is and whether any residue is acceptable: a degreaser is built to cut through heavier grease and grime, while IPA suits lighter cleaning immediately before a bonding or coating step where a completely residue-free surface matters.
Shop AIMS's range of degreasers →
What Is Deoxidation?
Deoxidation is a step in steelmaking where a deoxidizer — typically aluminium, silicon or manganese — is added to molten steel to remove dissolved oxygen before the steel solidifies, preventing gas porosity and improving the steel's internal soundness.
Fully deoxidized ("killed") steel has more consistent properties throughout than steel that wasn't properly deoxidized. This is a steelmaking-process term rather than something reflected in a product spec sheet, but it's part of why steel from a reputable mill behaves consistently batch to batch.
What Is a Depressed Centre Wheel?
A depressed centre wheel is a bonded grinding or cutting wheel with a recessed, dished centre, so the mounting flange and retaining nut sit below the level of the wheel's working face. That recess lets the wheel's cutting edge run flush against the workpiece without the hub or flange fouling the surface first — the standard profile for angle-grinder cutting and grinding discs, as opposed to a flat wheel mounted on a bench grinder.
What Is Descaling?
Descaling is the removal of mill scale — the brittle, dark oxide layer that forms on the surface of hot-rolled or heat-treated steel — before the steel is machined, welded, painted or otherwise finished. Mill scale left in place interferes with a clean weld, a painted or coated finish, and consistent machining, which is why descaling (whether by mechanical means such as grinding, blasting or wire brushing, or by chemical pickling) is a standard preparation step before those downstream processes rather than an optional extra. *(General engineering fundamentals — no dedicated AIMS article for this specific meaning of the term.)*
What Is Design Power? (Belt Drive Selection)
Design power is a belt drive's input power figure after being corrected by a Service Factor (Belt Drive Selection) multiplier — the actual power value a belt profile and sheave size are selected against, rather than the driving motor's raw nameplate power rating.
Selecting a belt off the motor's bare nameplate rating without applying the service factor is a common under-sizing mistake: a drive with frequent starts, shock loading or continuous duty needs more effective capacity than the nameplate figure alone suggests, and design power is the number that actually accounts for that.
What Is a Dial Caliper?
A dial caliper measures via a precision rack-and-pinion mechanism: as the sliding jaw moves along the beam, a rack gear cut into its underside drives a matching pinion inside the dial housing, rotating a pointer across the dial face — the operator reads the main scale (whole units) and the dial (fractional units) together for the final figure. Under the global standard JIS B 7507:2022, a 0–150mm metric dial caliper is specified to ±0.02mm maximum permissible error across its full range; an imperial 0–6 inch model meets ±0.001 inch. A dial caliper's real advantage is robustness — no electronics to fail in a coolant-rich environment, and it holds up to short-term shop-floor exposure noticeably better than a non-IP-rated Digital Caliper, though the rack-and-pinion mechanism itself is still vulnerable to chips causing the pointer to skip.
Read AIMS's full Dial Caliper Guide → for reading technique and Mitutoyo model comparison
Shop AIMS's range of dial calipers →
What Is a Dial Indicator (Dial Test Indicator)?
A dial indicator is a comparison instrument — it doesn't measure absolute distance directly, it measures the *difference* from a reference position, which is what makes it the standard tool for checking runout, taper, parallelism, perpendicularity and height variation. AIMS's guide splits the family in two: a plunger dial indicator has a spring-loaded spindle that moves linearly, with 5–100mm of travel (25mm standard) — the right choice for general runout, alignment and setup work; a dial test indicator (DTI) uses a pivoting lever arm instead, converting angular motion to a small linear reading over only 0.4–0.8mm of travel — the right choice for tight-access work and mill tramming, where "the plunger gives you range, the DTI gives you precision in tight spaces." Standard resolution is 0.01mm (or 0.001"), with high-precision models reaching 0.001mm. For lathe Runout specifically, a lever-type DTI is the correct tool — a plunger indicator drags on the rotating surface and gives a false reading.
Read AIMS's full Dial Indicator Guide → for plunger vs DTI selection and common applications
Shop AIMS's range of dial indicators & zero setters →
What Is a Diamond Blade? (Segmented, Continuous Rim & Turbo)
A diamond blade is a cutting disc with diamond particles bonded to its metal rim rather than mixed through an abrasive wheel — used for cutting concrete, masonry, tile, stone and asphalt — and the rim comes in three common styles suited to different jobs: segmented, continuous rim, and turbo.
Segmented blades have gaps cut between the diamond segments, which cool the blade and clear debris as it cuts, making them the fastest, most aggressive choice for concrete and masonry, at the cost of a rougher cut edge. Continuous rim blades run an unbroken diamond edge for the cleanest, most precise cut on tile, porcelain and stone, but need water cooling and cut more slowly. Turbo blades put a serrated pattern on a continuous rim, splitting the difference for general masonry and light concrete work where both speed and edge quality matter. Getting the Bond Hardness right for the material being cut matters just as much as picking the right rim style.
Read AIMS's full Diamond Blade Guide → for segmented, continuous rim and turbo blade selection
Shop AIMS's range of diamond blades →
What Is a Diaphragm Pump?
A diaphragm pump is a positive-displacement pump that moves fluid using a flexing diaphragm, driven by compressed air or an electric motor, rather than an impeller or rotating gear.
Its two defining practical advantages are self-priming operation (it doesn't need the pump body pre-filled with fluid to start moving it) and the ability to run dry without damage — a genuine safety margin most centrifugal pumps don't have, which is exactly why diaphragm pumps dominate chemical transfer, dewatering and drum-pumping applications where a tank might genuinely run empty mid-job. See Diaphragm Valve for the related but distinct component that uses the same flexing-diaphragm principle to control flow rather than move it.
Shop AIMS's range of pipe fittings →
What Is a Diaphragm Valve?
A diaphragm valve controls flow by flexing a rubber or PTFE diaphragm down onto (or away from) a seat, rather than using a ball, disc, gate or plug — giving it a completely smooth, crevice-free wetted flow path with no packing gland to leak.
Two body types cover different duty: weir-type, where the diaphragm seats onto an internal raised dam, needs only shallow diaphragm deflection (letting a stiffer PTFE diaphragm be used), gives excellent throttling control and longer diaphragm life, at the cost of a higher pressure drop when open; straight-through, where the diaphragm seats onto the bottom of a straight bore, needs deep deflection (ruling out PTFE — elastomer only), gives low pressure drop and full-bore flow, and handles slurries and solids far better, at the cost of shorter diaphragm life from the extra flex stress. Diaphragm material is selected the same way as any other wetted component: EPDM for water and dilute acids/caustics (but destroyed by petroleum and oils); PTFE for concentrated acids and hot caustics (weir-type only, and needs an elastomer backing since it's too stiff on its own); FKM/Viton for hydrocarbons and oils to 200°C; and butyl rubber specifically for vacuum and gas service, where its impermeability outperforms every other option. A diaphragm valve's real strength is aggressive chemicals and hygienic service — food, beverage and pharma applications where a Ball Valve's stem packing or a Gate Valve's exposed threads would eventually degrade and leak — but it's genuinely limited to lower pressure (most rated 6–10 bar) and lower temperature (up to roughly 150°C) than the metal-bodied valve types, and it operates on multi-turn linear motion rather than fast quarter-turn actuation.
Read AIMS's full Diaphragm Valve Guide →
Shop AIMS's range of pipe fittings →
What Is Dichromate (Yellow Zinc)?
Dichromate refers to the chromate conversion coating applied over standard zinc electroplating to boost its corrosion resistance and give it the characteristic yellow/gold tint — commonly just called "yellow zinc." AIMS's own guide describes it as standard zinc plate (around 5–12 microns) plus a roughly 8-micron chromate conversion seal, giving "slightly better" corrosion resistance than plain zinc plate alone, and it's the finish most associated with general automotive and workshop fasteners.
Read AIMS's full Zinc Plated vs Galvanised vs Stainless: Bolt Coatings Guide →
What Is a Die Grinder?
A die grinder is a small, high-speed rotary tool — electric, cordless or pneumatic — with a collet that holds carbide burrs, mounted abrasive stones or thin cut-off wheels, purpose-built for precision metal removal in confined spaces: porting engine heads, dressing welds, deburring castings and removing spot welds. It runs across a wide speed band depending on the accessory and job — from around 2,400 RPM for low-speed cup-wheel work up to 25,000 RPM or more for fine detail work with small carbide burrs, with 22,000 RPM the typical workshop default for general burr work. Pneumatic die grinders are the workshop standard for sustained production work (needing a 3HP+ compressor, but with the best power-to-weight ratio); electric models suit a 240V workshop without compressed air and run more efficiently over long sessions; cordless models are handy for quick cleanup but deplete quickly under sustained high-RPM use and aren't recommended for extended porting sessions.
Read AIMS's full Die Grinder Guide → for pneumatic vs electric vs cordless selection
Shop AIMS's range of die grinders →
What Is a Die Nut?
A die nut is a hexagonal, hardened-steel nut with thread-cutting teeth machined into its bore, spun onto a damaged bolt, stud or threaded rod with a spanner to clean up and re-form an existing thread — rust, corrosion, paint and light mechanical damage are all fair game. What a die nut can't do is cut a fresh thread from scratch: spun onto bare, unthreaded rod expecting it to cut a new thread, it simply won't engage — that job belongs to a Button Die instead, whose round, progressive-cutting geometry is built for exactly that. Thread chasers are essentially die nuts packaged as multi-size production kits, and thread files (hand files with multi-pitch cutting teeth on each face) do a lighter-duty version of the same restoration job, though they struggle once a fastener is hardened enough that the file's own teeth can't bite.
Read AIMS's full Thread Restoration Tools Guide → for die nuts vs chasers vs thread files
Shop AIMS's range of die nuts →
What Is a Die Stock (Die Holder)?
A die stock (die holder) is the handle assembly that grips a Button Die and provides the leverage needed to cut an external thread by hand. A split (adjustable) die needs a die holder with both clamp screws and an adjustment screw to fine-tune the cut diameter, while a solid button die — which can't be adjusted — uses a simpler holder with no adjustment mechanism at all. Standard die stock sizes run from around 1" to 2½" to suit the common die sizes AIMS stocks.
Read AIMS's full Tap & Die Selection Guide → for die holder selection by die type
What Is Dielectric Strength?
Dielectric strength is the maximum electric field an insulating material can withstand before it breaks down and starts conducting current, usually expressed in kilovolts per millimetre (kV/mm). It's the underlying property that makes an insulating material — the sleeve on a cable, the tubing around a joint — actually safe to use at a given voltage, and it's why Heat Shrink Tubing and cable insulation are rated for specific voltage classes rather than treated as one-size-fits-all.
What Is a Diff Lock?
A diff lock (differential lock) is a driver-engaged mechanism that forces both wheels on an axle to rotate at exactly the same speed, overriding the differential's normal function of letting the outer wheel turn faster than the inner wheel through a corner. It's used to maximise traction on loose, muddy or uneven surfaces — where a standard differential would send all the drive to whichever wheel has the least grip and spin uselessly — at the cost of harder steering and higher driveline stress, which is why it's disengaged again once back on a hard, high-traction surface.
What Is a Digital Caliper?
A digital caliper reads position through a capacitive encoder: as the slider moves along the beam, the capacitance between the slider's electrodes and the beam's printed pattern changes, and that change is decoded into the reading shown on the LCD display — a solid-state measurement with no moving mechanical parts inside the slider itself. There are two underlying encoder technologies, and the difference matters: incremental encoders count position changes from power-on and need re-zeroing every time the caliper is switched on, losing their reference point if power is lost; absolute encoders (Mitutoyo's patented ABSOLUTE technology, among others) read a unique position pattern at every point along the beam, so the caliper always knows where it is regardless of power cycles or battery changes. IP rating matters more than the spec sheet suggests: an unrated caliper is fine for dry handling only, IP54 ("protected against splashing water from any direction") is the workshop default for general engineering, and IP67 ("completely dust-tight," survives 1m water immersion for 30 minutes) is the standard for CNC work with active coolant — coolant ingress is the single biggest failure cause for digital calipers in metalworking environments. Typical accuracy runs ±0.02–0.03mm depending on tier.
Read AIMS's full Digital Caliper Guide → for IP ratings and absolute-encoder selection
Shop AIMS's range of digital calipers →
What Is a Digital Height Gauge?
A digital height gauge measures vertical dimensions referenced from a surface plate, scribes layout lines at precise heights, and verifies part dimensions against that reference datum — the surface plate itself acts as the absolute zero, with every reading representing height above that surface. Under JIS B 7517 and ISO 13225, a 0–300mm vernier height gauge is typically accurate to about ±0.04mm, a digital height gauge in the same range to about ±0.03mm, and a premium ABSOLUTE-encoder digital model to about ±0.025mm — accuracy degrades noticeably with range, with a 1000mm gauge reaching only ±0.07–0.08mm typical. A digital height gauge with an absolute (rather than incremental) encoder holds its zero through power cycles and battery changes, which is the difference that justifies the premium pricing for inspection-grade work over a cheaper workshop-tier unit that loses zero on power-off.
Read AIMS's full Height Gauge Guide → for vernier vs digital accuracy and model comparison
Shop AIMS's range of measuring tools →
What Is DIN? (Deutsches Institut für Normung)
DIN is the German national standards body — its name translates to the German Institute for Standardisation — responsible for developing and publishing the DIN standards used throughout German (and, by extension, much of European) engineering, manufacturing and construction practice.
A large share of DIN's most widely-used standards have since been formally adopted, sometimes with minor amendment, as harmonised EN (European Norm) standards, often published under the combined "DIN EN" designation. DIN's influence in Australian industrial trade runs deep despite Australia having no formal adoption relationship with it: DIN 912 socket head cap screws, already covered as its own entry in this glossary's Fasteners & Threading category, is the single most common DIN standard Australian trade encounters, and DIN-numbered grade designations turn up regularly in cross-referencing material specs against ASTM and Australian equivalents.
What Is DIN 471 (Retaining Rings, External)?
DIN 471 is the German (internationally adopted) standard specifying external retaining rings (circlips) for shafts — the standard defines both the ring's own dimensions and the matching groove geometry (depth, width, shoulder profile) that must be machined into the shaft to receive it.
Sizing under DIN 471 is based on the shaft diameter itself, not the ring or the groove — a DIN 471–25 is sized for a 25 mm shaft. Its companion standard, DIN 472, covers internal retaining rings for bores using the same logic (nominal size equals bore diameter) — see Retaining Ring above for how the two types differ in use, and note that metric DIN groove profiles are not interchangeable with imperial retaining-ring standards.
Read AIMS's full Circlip Guide → for DIN 471/472 sizing tables
Shop AIMS's range of circlips, snap rings & retaining rings →
What Is DIN 580?
DIN 580 is the German (metric) standard for plain eye bolts — the uncollared eye bolt type rated for vertical, in-line lifting only, with no partial de-rating available for angled loads. See Eye Bolt above for the full plain-vs-collared comparison.
What Is DIN 766?
DIN 766 is the German standard for short-link chain, broadly equivalent in role to the Australian AS 2321 — both describe calibrated, close-tolerance chain suited to chain blocks and lever hoists rather than general-purpose towing chain. AIMS sources chain against both specs depending on the equipment manufacturer's original requirement.
What Is DIN 912 (Socket Head Cap Screws)?
DIN 912 is the German (now internationally adopted) standard specifying socket head cap screws — cylindrical head, internal hex drive, available M3 through M64 with M3–M30 most common in Australian industrial supply — dimensionally compatible with the equivalent international standard, ISO 4762 — Socket Head Cap Screws (metric) below.
Class 12.9 is the default engineering property class for DIN 912 screws (see Property Class above), specified as standard for dies, jigs, fixtures and high-strength joints; class 8.8 and 10.9 cover lighter general industrial use. AIMS's own guide gives worked dry-torque figures across all three classes at common sizes.
Read AIMS's full Socket Head Cap Screw Guide → for the complete size, grade and torque table
Shop AIMS's range of socket head cap screws →
What Is DIN 933 (Hex Bolts, Full Thread)?
DIN 933 is the international standard (also adopted as ISO 4017) for full-thread hexagon head bolts — the thread runs the entire length from head to tip, with no unthreaded shank section at all, as distinct from ISO 4014 — Hex Head Bolts (Metric) above.
Full-thread bolts to DIN 933 are the right choice for tapped-hole applications needing maximum thread engagement, and for shorter fasteners where a plain shank section isn't practical anyway — but because the thread roots (rather than a solid shank) sit at the shear plane in a through-bolted joint, they carry a stress-concentration disadvantage in genuinely shear-loaded structural connections compared with a partial-thread bolt of the same grade and diameter.
Read AIMS's full Hex Bolt Guide → for full-thread vs partial-thread selection guidance
Shop AIMS's range of hex bolts →
What Is a Dogman (Dogging)?
A dogman is a person who holds an Australian High Risk Work Licence in the "DG" (dogging) class, qualifying them to sling loads, direct a crane or hoist operator using hand signals or two-way radio, and select and inspect the lifting gear for a lift. Dogging is a licensed activity under Australian WHS law — it isn't just "whoever's available on site" — and a dogman's licence also covers basic rigging work, since the two skill sets overlap heavily in practice.
What Is DOL (Direct-On-Line) Starting?
DOL (Direct-On-Line) starting is the simplest way to start a three-phase Induction Motor: a contactor connects the motor straight to full mains voltage in one step. It's the cheapest and mechanically simplest of the four common starting methods — one contactor, one overload relay, nothing to tune — but it draws the highest starting current of the four, typically 6–8 times the motor's full-load amps (FLA), for a second or two while it comes up to speed.
There's no fixed kW cut-off above which DOL stops being appropriate, whatever a quick rule of thumb might suggest — some sources quote a rough convention of reduced-voltage starting above roughly 5.5–7.5 kW on a 400V supply, but working electricians describe that as a crude approximation, not a real calculation. What actually matters is the voltage dip your specific starting current causes on your specific supply — its fault level and impedance — which is a site-specific question for a licensed electrician against AS/NZS 3000, not something a general guide can answer. See Star-Delta (Y-Δ) Starting, Soft Starter and VFD (Variable Frequency Drive) for the three step-up alternatives, in order of increasing cost and decreasing starting current.
Read AIMS's full Motor Starting Methods Guide → for the full DOL vs star-delta vs soft starter vs VFD comparison
What Is a Dome Head Screw?
A dome (round) head is a tall, hemispherical head with a flat underside, sitting noticeably proud of the surface — more decorative than functional in modern industrial work, though still used in electrical terminal and restoration applications, as distinct from the flatter Truss Head profile.
It sits within AIMS's broader screw-head-type family alongside pan, button, countersunk and bugle heads — see Flat Head below for the countersunk variant, and AIMS's own guide for the full comparison across all common head shapes.
Read AIMS's full Screw Head Types Guide → for the complete head-shape and drive-type comparison
What Is a Double V-Belt? (Hexagonal Belt)
A double V-belt — also called a hexagonal belt — has a V-profile moulded onto both sides of the belt rather than just one, letting it transmit power from either face.
This makes it the right choice for serpentine drive layouts, where the belt needs to both drive and be driven by pulleys on opposite sides of its run, or any system needing power take-off from both faces of the same belt run — a configuration a standard single-sided Wrapped V-Belt or Raw-Edge / Cogged V-Belt simply can't provide.
Read AIMS's full V-Belt Sizing & Identification Guide →
Shop AIMS's range of industrial drive & conveyor belts →
What Is a Dowty Washer? (Bonded Seal)
A Dowty washer — the generic trade name is a bonded seal — is a metal washer with a ring of vulcanised rubber bonded to its inner bore. Tightened against a flat machined face, the rubber compresses to form a leak-tight static seal, while the metal body acts as a hard stop that limits compression to around 70–80% of the rubber's free height, sealing without the rubber splitting or extruding out from under load.
The rule that matters most in the workshop: bonded seals only work on parallel-thread fittings (BSPP) with a flat face for the rubber to compress against — they will not seal a tapered thread (BSPT or NPT), which needs PTFE tape or an anaerobic thread sealant instead. Rubber compound matters just as much as thread type: NBR (nitrile) covers most pneumatic air, hydraulic oil and diesel duty, FKM (Viton) is needed for hot oil, ethanol-blend fuel or higher temperatures, and EPDM is for brake fluid and water systems — putting an NBR seal on an ethanol fuel line or EPDM on a mineral-oil port is a common and avoidable failure. In pneumatic circuits specifically, Dowty washers turn up sealing regulator ports, gauge connections and fitting faces wherever a BSPP thread meets a flat spotface.
Read AIMS's full Dowty Washer & Bonded Seal Guide → for sizing, torque figures and the BSPP vs BSPT quick test
What Is a Drawbar (Trailer)?
A drawbar is the rigid tow-bar assembly connecting a Pig Trailer / Dog Trailer's own front axle group to the vehicle towing it, as distinct from a semi-trailer, which has no front axle of its own and instead rests its forward weight directly on the towing vehicle's Fifth Wheel Coupling via its King Pin. A drawbar-coupled trailer tracks its own steered path rather than being carried by the towing unit, which changes how it behaves in reversing and tight turns compared with a semi-trailer.
What Is a Drill Chuck?
A drill chuck is the clamping mechanism — keyed or keyless — that holds a drill bit or other round-shank accessory in a drill, drill press or lathe spindle. A keyless chuck tightens by hand, twisting the sleeve for a fast bit change, but its grip strength depends entirely on hand-tightening force, and under heavy load a keyless chuck can release; a keyed chuck uses a geared mechanism and a chuck key for genuinely higher clamping force, which is why keyed designs remain the more reliable choice for heavy metalwork and precision operations, hand-tightening convenience aside. Chucks mount via a JT (Jacobs Taper) — six standard sizes from 1JT (a small 9.75mm taper for hobby and micro-drilling chucks) up to 5JT (31.75mm, heavy industrial lathe tailstocks) — and JT sizes are never interchangeable, since the chuck's female taper has to exactly match the arbor's male taper. A "0–13mm" chuck closes fully to zero, gripping drills down to around 0.5mm (with precision dropping below about 1mm), while a "1–13mm" chuck's jaws don't fully close and can't grip anything finer than about 1mm — a distinction worth checking before ordering a replacement chuck for fine work.
Read AIMS's full Drill Chuck Guide → for the complete JT taper size table and capacity ranges
Shop AIMS's range of drill chucks →
What Is a Drill Press?
A drill press is a bench or floor-mounted stationary drilling machine that holds the workpiece and drilling motor in a fixed, perpendicular relationship, with adjustable spindle speed — a setup a handheld drill simply can't match for accuracy, repeatability or the ability to safely apply real downward feed pressure. It's the standard tool for any hole that needs to be genuinely perpendicular, precisely located, or drilled at a repeatable production rate, as distinct from the on-site, self-clamping role a Magnetic Drill fills where the workpiece itself can't be brought to a benchtop machine.
Shop AIMS's range of drill presses →
What Is Drilling?
Drilling is the machining process of cutting a round hole into a solid workpiece using a rotating cutting tool — most commonly a twist drill bit — fed axially into the material. It's one of the most fundamental machining operations in any workshop, underpinning everything from a simple clearance hole for a bolt through to a precision bore later finished by a Reamer or Bore Gauge-checked to size. The right drill bit material and geometry depends entirely on what's being drilled: HSS for wood, mild steel and general metals; HSS-Co (Cobalt High-Speed Steel) for stainless steel, which work-hardens and will rapidly blunt a plain HSS bit; carbide-tipped or SDS bits for masonry and concrete; and diamond-tipped bits (with water cooling, no hammer action) for ceramic and porcelain tile.
Shop AIMS's range of drilling →
What Is Drive Torque?
Drive torque is the rotational force actually required to turn a fastener during installation — the combined effort of overcoming thread friction, under-head (or under-nut) friction, and, where present, the resistance of a locking feature — as distinct from the final tightening torque used to develop clamp force once the fastener is seated.
For self-tapping and self-drilling screws specifically, drive torque also has to overcome the resistance of forming the mating thread in the base material itself, which is why AIMS's Tek screw series ratings exist — selecting too light a series for the steel thickness causes the drill point to stall rather than drive cleanly through. Prevailing Torque below is the related but distinct concept of resistance that continues *after* the fastener is fully seated. *(General engineering fundamentals, cross-referenced against AIMS's own self-tapping screw guide — no single dedicated AIMS article for the general drive-torque concept itself.)*
What Is a Drop-In Anchor?
A drop-in anchor is a mechanical anchor dropped into a pre-drilled hole and expanded flush with the surface using a dedicated setting tool, which drives an internal expander plug down into the anchor body to flare its lower end outward against the hole wall — once set, it functions as an internally threaded socket that accepts a standard bolt.
That flush, internally threaded finish is what sets it apart from a Wedge Anchor, which leaves a threaded stud protruding — a drop-in anchor suits overhead and suspended-ceiling fixings, machinery mounting points, or anywhere a clean flush surface matters and the bolt itself can be added later. Using the correctly sized setting tool for the anchor's diameter is essential: an undersized or missing setting tool is the most common reason a drop-in anchor ends up under-expanded and under-rated for its intended load.
Read AIMS's full Concrete Anchor Guide → for drop-in anchor setting tool sizing
Shop AIMS's range of stud anchors →
What Is a Drum Winch?
A drum winch spools its entire wire rope length onto a rotating drum, giving continuous long-distance pulling in one motion, whereas a Come-Along (Cable Puller) ratchets the rope through incrementally and needs to be re-anchored or re-gripped as it travels. Winches suit longer, sustained pulls (vehicle recovery, load positioning over distance) where the drum can be power-driven or hand-cranked; a come-along suits shorter, more precise tensioning jobs where portability and fine control matter more than speed.
Shop AIMS's range of winches →
What Is a DTI Washer (Direct Tension Indicating)?
A DTI washer (Direct Tension Indicating washer) is a hardened washer with small raised protrusions (bumps) on one face that flatten measurably as the joint is tightened, giving a direct, visual, mechanical readout of achieved bolt tension — a feeler gauge is used to check the remaining gap under the bumps against a specified maximum, confirming the target preload has been reached.
DTI washers are specified in structural steelwork as an independent, physical cross-check on Angle Controlled Tightening or torque-based methods — rather than trusting torque or turn count alone, the installer gets a direct mechanical confirmation that the actual bolt tension is where it needs to be. They're most associated with high-strength structural bolting to AS/NZS 1252.1 — High Strength Bolts (structural).
Read AIMS's full Structural Bolt Tensioning to AS 4100 Guide → for the DTI method, minimum tension values and AIMS's stocked Durasquirt/Squirter DTI range
Shop AIMS's range of washers →
What Is a Dual-Stage Regulator? (Two-Stage Gas Regulator)
A dual-stage (or two-stage) gas regulator drops cylinder pressure down to the working delivery pressure in two controlled internal steps rather than one, keeping the outlet flow stable and consistent for the entire life of the cylinder — right down to the last usable bar. That's the key advantage over a Single-Stage Regulator, which does the job in one step and lets delivery pressure gradually creep upward as cylinder pressure falls, an effect called Regulator Droop.
Because the flow doesn't drift, a dual-stage regulator is the trade standard for production welding, long continuous runs and gas-critical TIG (Welding) work, where a wandering shielding-gas flow can visibly affect weld quality. It costs more than a single-stage unit, so it's specified deliberately for that precision rather than used as a default on every cylinder. Both types are built to the same AS 4267 — Gas Regulator Standard (Type 10 Inlet) requirements for inlet fitting, safety relief and pressure rating.
Read AIMS's full Welding Gas Regulator Guide →
What Is Ductility?
Ductility is a material's ability to deform — stretch, bend or draw into wire — under tensile load without fracturing. High-ductility materials give a visible warning (bending, necking) before they fail; low-ductility materials can fail suddenly with little or no warning.
It's why grade 8.8 bolts are generally preferred over 12.9 for shock-load applications: the higher-grade bolt is stronger but more brittle, while the 8.8 bolt's greater ductility lets it yield rather than snap under a sudden overload. Ductility is usually measured and reported as Elongation — the percentage a test sample stretches before breaking.
Read AIMS's full Steel Grades Comparison Chart →
What Is Duplex Roller Chain?
Duplex roller chain runs two strands of roller chain side by side on the same pitch and sprocket, giving roughly 1.7× the load capacity of Simplex Roller Chain — the middle option between simplex and the higher-capacity Triplex Roller Chain for multiplying a drive's load capacity without changing the chain's pitch size.
Choosing duplex over a larger single-strand pitch keeps the sprocket diameter and overall drive geometry more compact for a given load rating, which matters where space around the drive is tight. See Roller Chain Anatomy for what each individual strand is actually built from.
Read AIMS's full Roller Chain Guide →
Shop AIMS's range of chain & sprockets →
What Is Duplex Stainless Steel?
Duplex stainless steel has a mixed microstructure — roughly half austenitic, half ferritic — with higher chromium and lower nickel content than 316, giving it higher strength and better resistance to chloride pitting and crevice corrosion than standard austenitic grades.
It's specified for the most demanding marine and chemical environments — long-term saturated saltwater immersion, sustained mud anchoring and similar conditions where even 316 can develop crevice corrosion in oxygen-poor pockets over time. Duplex 2205 typically costs 30–50% more than 316, which is why it's reserved for applications where 316's limits have genuinely been reached, rather than used as a default upgrade.
Read AIMS's full Stainless Chain Guide →
What Is Duty Cycle? (Air Compressor)
An air compressor's duty cycle is the percentage of time it can run within a given period without overheating. Single-stage, direct-drive units typically manage 25–50%; belt-drive, two-stage piston compressors reach 60–75%; rotary screw compressors are built for 100% continuous running. Running a piston unit beyond its rated duty cycle — chasing a continuous-demand job like spray painting on a machine built for intermittent tool use — is one of the leading causes of premature compressor failure in Australian workshops.
*(Not to be confused with the separate motor duty cycle rating tracked elsewhere in this glossary — the S1–S9 letter-and-number classes used for electric motors. Same term, different equipment and a different rating basis: an air compressor's duty cycle is a simple running-time percentage, not a standardised letter code.)* See Piston Compressor (Reciprocating) and Rotary Screw Compressor for which type suits which duty pattern.
Read AIMS's full Air Compressor Guide → for duty-cycle figures by compressor type
What Is Duty Cycle (Electric Motor)?
A motor's duty cycle describes the relationship between its operating time and rest time, using a standard letter-and-number code: S1 (continuous duty) means the motor is designed to run indefinitely at rated load without exceeding its temperature rating, and is the standard rating for most industrial motors. S2 through S9 cover various intermittent, short-time and cyclic duty patterns — a motor rated S2-30min, for instance, can run continuously for 30 minutes before needing to cool, rather than running indefinitely.
Duty cycle sits alongside Motor Insulation Class and IE Efficiency Class as one of the key nameplate specs to check before selecting or replacing a motor — a continuous-duty (S1) application fitted with a motor only rated for intermittent duty will overheat and fail prematurely, even if its kW rating looks adequate on paper. *(Not to be confused with the separate air-compressor duty-cycle rating tracked elsewhere in this glossary — same term, different equipment and a different rating basis.)*
Read AIMS's full Electric Motor Guide → for the full S1–S9 duty rating reference
What Is a Dynabolt®? (Ramset Trademark — Sleeve/Wedge Anchor)
Dynabolt® is Ramset's trademarked sleeve/wedge anchor product line — a torque-controlled mechanical anchor that expands an outer sleeve against the drilled hole as its nut is tightened, functionally Ramset's own specific product within the generic Wedge Anchor category above.
Like Nyloc® and Molly® elsewhere in this glossary's fastener range, "Dynabolt" has become genericised in Australian trade speech — tradies commonly say "Dynabolt" for any sleeve or wedge-style expansion anchor regardless of who actually made it, the same pattern behind Chemset® above becoming the everyday word for chemical anchoring generally. Ramset's current Dynabolt Plus line adds a patented pull-down expansion sleeve that closes gaps of up to 5 mm and actively pulls the fixture down against the substrate as it expands, on top of the base sleeve-anchor mechanism — a refinement Ramset markets as reducing the loose fit that can otherwise occur before a sleeve anchor is fully tightened.
Read AIMS's full Concrete Anchor Guide → for AIMS-stocked sleeve/wedge anchor equivalents
Shop AIMS's range of stud anchors →
E
What Is Edge Distance? (Anchor Installation)
Edge distance is the minimum distance from the centre of a drilled anchor hole to the nearest free edge of the concrete or masonry element, specified to stop the substrate cracking or spalling outward as the anchor is installed and loaded.
Too little edge distance is one of the most common on-site anchor failures, and it isn't the same requirement for every anchor type: a Wedge Anchor generally needs more edge distance than a Chemical Anchor of the same diameter, because an expansion anchor imposes radial bursting stress on the surrounding concrete that a bonded chemical anchor simply doesn't. AS 5216 sets minimum edge distance and spacing values per anchor diameter and Embedment Depth combination — the two dimensions are specified together, since both answer the same underlying question about how much substrate is actually available to carry the anchor's load.
Read AIMS's full Chemical Anchor Guide → for embedment and edge distance tables
What Is the Elastic Range?
The elastic range is the span of stress a material can be loaded through and still return fully to its original shape once the load is removed, with no permanent deformation. Once stress exceeds the elastic limit — a point very close to, but technically distinct from, the yield point on a Stress/Strain curve — some deformation becomes permanent (plastic) even after the load is taken off. Staying within the elastic range is the basic design assumption behind almost every fastener, bracket and structural member in ordinary service: a bolt torqued correctly should never be loaded anywhere near its yield point, let alone past it. *(General engineering fundamentals — no dedicated AIMS article for this term.)*
What Is an Electric Motor?
An electric motor is a machine that converts electrical energy into rotational mechanical energy, used to drive pumps, fans, conveyors, compressors and countless other pieces of industrial equipment. The Induction Motor is by far the most common electric motor type in Australian industry, but AC and DC motor designs both fall under this broader term — see the Induction Motor entry for the technical detail behind the everyday name.
How a motor is started matters as much as the motor itself on anything beyond the smallest single-phase unit — see DOL (Direct-On-Line) Starting, Star-Delta (Y-Δ) Starting, Soft Starter and VFD (Variable Frequency Drive) for the four common methods, in order of increasing cost and decreasing starting current. Getting the starting method right is often what determines whether a motor circuit trips on start-up or runs cleanly — see Circuit Breaker for how trip curve selection (Type B/C/D) interacts with this.
Read AIMS's full Electric Motor Guide → or Motor Starting Methods Guide → (DOL vs star-delta vs soft starter vs VFD)
Shop AIMS's range of electric motors →
What Is Electrical Fluting (Bearing)?
Electrical fluting is regularly spaced, washboard-pattern groove damage to a bearing's Race, caused by stray electrical current — typically from a variable frequency drive (VFD) — discharging as small arcs through the bearing as it rotates. It's increasingly common on VFD-driven motor plant specifically, has a distinctive appearance that's hard to mistake for mechanical fatigue damage, and is often accompanied by a burnt-grease smell from the localised arcing heat.
Prevention options include a Hybrid Bearing (ceramic rolling elements, which don't conduct current), insulated bearings, shaft grounding rings, conductive grease, and VFD output chokes or shielded motor cables to reduce the stray current in the first place — dealing with the cause rather than the symptom.
Read AIMS's full Rolling Bearings: Types, Selection, Fitting & Failure Guide →
What Is Electroplating?
Electroplating is the process behind standard Zinc Plating: electrodeposition of a metal coating onto a part using an electrical current passed through a metal-salt solution. For zinc specifically, AIMS's own guide gives a typical coating thickness of 5–25 microns (usually 5–12 µm) — thin enough that plated threads stay true to their original tolerance, unlike Hot Dip Galvanizing, which adds enough coating thickness that galvanised nuts need to be tapped oversize to still fit.
Read AIMS's full Zinc Plated vs Galvanised vs Stainless: Bolt Coatings Guide →
What Is Elongation?
Elongation is the standard measurement of Ductility — the percentage increase in length a test specimen shows just before it fractures in a tensile test, compared with its original length.
A higher elongation percentage means a more ductile, forgiving material; a lower percentage means a stiffer, more brittle one that gives less warning before failure. It's reported on mill certificates alongside Tensile Strength / Ultimate Tensile Strength and Yield Strength as one of the three standard numbers that define a material's mechanical behaviour.
What Is Embedment Depth? (Anchor)
Embedment depth is how far a bolt, threaded rod or Chemical Anchor is set into its drilled hole, measured from the surface of the base material to the tip of the anchor — and it's one of the two or three biggest levers on an anchor's actual pull-out and shear capacity, alongside anchor diameter and concrete strength.
Under AS 5216, minimum and effective embedment depths are set per anchor diameter and product, and increasing embedment is the standard way to lift a given anchor's rated load without stepping up to a larger diameter — AIMS's own guide publishes worked embedment tables from M8 through M24 alongside the matching borehole diameter for each size. Embedment depth and Edge Distance below are usually specified together, since both drive the same underlying question: how much substrate is actually available to resist the anchor's load.
Read AIMS's full Chemical Anchor Guide → for M8–M24 embedment and borehole diameter tables
What Is Emery Cloth?
Emery cloth is an abrasive cloth coated with emery — a naturally occurring aluminium oxide and iron oxide mineral — supplied in sheets or rolls for general-purpose finishing, rust removal and de-scaling by hand. Purpose-made aluminium oxide and silicon carbide cloths have largely overtaken true emery for most jobs, since they cut faster and more consistently, but the name has stuck in trade use for any fine abrasive cloth used by hand.
Shop AIMS's range of abrasive rolls — emery and aluminium oxide →
What Is EN? (European Norm)
EN is the official designation given to a standard published by one of Europe's three recognised standards organisations — CEN, CENELEC or ETSI — and adopted as a harmonised standard across all EU and EEA member states, meaning every national body (including Germany's DIN) must adopt it as an identical national standard rather than maintain a conflicting one.
Because EN standards are the harmonised route to demonstrating compliance with EU product legislation, they sit behind a lot of the European-market electrical and safety equipment Australian industrial suppliers import — an EN standard number on a datasheet is often the underlying technical basis a product also needs to meet RoHS or CE-marking obligations, even though the standard itself, the directive and the marking are three separate things.
What Is EN 388? (Cut-Resistant Gloves)
EN 388 is the European standard for mechanical hazard performance in protective gloves, and it's the rating system most cut-resistant work gloves sold in Australia carry alongside — or instead of — the Australian AS/NZS 2161.4 equivalent.
The full marking is more than a single number — see EN 388 Rating Structure (4 Digits + ISO 13997 Letter) for what each part actually means, since a single-digit summary misses most of the useful detail.
Read AIMS's full Work Glove Types guide →
Shop AIMS's range of hand protection →
What Is the Full EN 388 Rating? (4 Digits + ISO 13997 Letter)
A full EN 388 glove rating has up to six parts, and reading only the first digit misses most of what the rating actually tells you: four digits covering abrasion resistance (0–4), blade cut resistance under the older Coupe test (0–5), tear resistance (0–4) and puncture resistance (0–4), followed by an ISO 13997 — Cut Resistance Testing letter grade (A–F, replacing the less reliable Coupe test for genuine cut performance) and an optional "P" suffix for impact protection across the knuckles.
The letter grade is the one worth paying closest attention to for genuine cut-hazard work, since the Coupe-test digit can be misleading on very sharp or textured blades — a glove can look strong on the older digit scale while its ISO 13997 letter tells a more accurate story.
Read AIMS's full Work Glove Types guide →
Shop AIMS's range of hand protection →
What Is EN 407? (Heat-Resistant Gloves)
EN 407 is the European standard for gloves protecting against thermal risks — heat and/or fire — and it's the standard most Australian welding gloves carry alongside their local AS/NZS 2161.4 — Protective Gloves marking, both rating the same underlying properties: flame spread, contact heat, convective heat, radiant heat and molten metal splash resistance.
A glove's specific Glove Leather Grade (Cowhide/Goatskin/Pigskin/Elkskin/Deerskin) is what actually delivers the performance behind the rating — the standard measures the outcome, not the material choice itself.
Read AIMS's full Welding Gloves Guide →
Shop AIMS's range of hand protection →
What Is an Endless Belt? (Power Transmission)
An endless belt is manufactured or joined as a single continuous closed loop — moulded or vulcanised with no mechanical fastener at the join — and is the standard construction for virtually every modern V-belt and timing belt in industrial use.
The alternative construction is a Link Belt (Segmented / Jointed Belt), which uses a mechanical connector instead of a seamless join. An endless belt is inherently stronger at the join (there's no join to be a weak point) and runs smoother, but it must be fitted over the pulleys as a complete loop — it can't be shortened or lengthened on site, and a snapped endless belt means a full replacement rather than a repair.
Read AIMS's full Belt vs Chain Drives Guide →
Shop AIMS's range of industrial drive & conveyor belts →
What Is an Endless Splice? (Conveyor Belt)
An endless splice is a vulcanised joint that permanently fuses two belt ends together with rubber and vulcanising compound under heat and pressure (or, on some belt types, a cold-cure adhesive process), turning an open length of belting into one continuous, seamless loop — hence "endless."
It's the stronger and longer-lasting of the two ways to join a conveyor belt, holding close to the belt's full rated strength and running smoothly over pulleys and through Skirting (Skirt Board, Conveyor) with no external hardware to catch on chutes or scrapers — the right choice for continuous heavy-duty, mining and long-centre-distance installations where downtime for a joint failure is expensive. The trade-off is the install itself: a proper vulcanised splice needs a trained crew, specialised press equipment and several hours (longer on large belts) of downtime, against the fast, tool-based install of a Mechanical Fastener (Conveyor Belt) joint — which is why workshop repairs and belts that need to come apart again favour the mechanical option instead. AIMS's own conveyor components guidance sums up the trade-off directly: mechanical splicing for workshop and light industrial repair, vulcanised for mining and heavy industrial duty.
Shop AIMS's range of conveyor components & steel rollers →
What Is an Engine Brake (Jake Brake)?
An engine brake is a device — most commonly a compression-release type, popularly known by the Jacobs Vehicle Systems trademark "Jake Brake" — that turns a heavy vehicle's diesel engine itself into a braking device on long descents, by opening the exhaust valves near the top of the compression stroke so the engine absorbs energy instead of returning it, rather than relying solely on the Air Brake System. It's especially valuable on long, steep descents where continuous friction braking would otherwise overheat the drum or disc brakes — but its distinctive stuttering exhaust note has led some Australian towns to post "no engine braking" signage in built-up areas.
What Is an Engineer's Square?
An engineer's square is a fixed-angle precision tool — a stock (the thick base) and a blade set at exactly 90° to it — used as a reference standard for verifying true squareness and scribing perpendicular lines, with no moving parts to introduce error. It's single-purpose by design, which is exactly what makes it more accurate than a Combination Square for genuine precision inspection work, even though the combination square is more versatile day to day. Accuracy is graded under DIN 875 across four tolerance classes (00, 0, 1, 2) — at 150mm blade length, tolerances range from around 0.004mm (Grade 00, calibration-master standard) to 0.070mm (Grade 2, general workshop); most Australian industrial workshops standardise on Grade 1 or 2 for everyday use, reserving Grade 00 for calibration and inspection reference.
Read AIMS's full Engineers Square, Combination Square & Steel Rule Guide → for DIN 875 grades and selection
Shop AIMS's range of engineers squares →
What Is an EP Additive (Extreme Pressure)?
An EP additive is a chemical compound — typically sulphur, phosphorus or chlorine-based — blended into a Grease or oil that activates specifically under high contact stress and high surface temperature, forming a sacrificial boundary film on the metal surfaces at exactly the moment ordinary lubrication would otherwise break down. AIMS's own guide is clear that EP is an additive package, not a thickener type — it sits alongside whichever thickener (lithium, polyurea and so on) is doing the grease's structural job — and it's needed for heavily loaded sliding contacts, shock loads and slow-speed bearings running in boundary lubrication, but is generally unnecessary (and sometimes counter-productive) for lightly loaded, high-speed rolling-element bearings.
Read AIMS's full Grease Selection Guide: Types, NLGI & EP →
What Is EPDM? (Ethylene Propylene Diene Monomer)
EPDM is a synthetic rubber with excellent resistance to water, steam, ozone and UV, and a wide working range of about -50°C to +150°C — the standard choice for outdoor seals, water systems and weatherproofing.
Its critical weakness is petroleum oils: EPDM is destroyed within hours of sustained contact with oil or fuel, which is the single most common preventable gasket failure when it's mistakenly substituted for NBR (Nitrile Rubber) in an oil-side application. As a simple rule, water-side and weather-exposed service favours EPDM; oil- and fuel-side service favours NBR.
Read AIMS's full Rubber Sheet Guide →
Shop AIMS's range of rubber sheets & rolls →
What Is an Epoxy Adhesive? (Two-Part)
Epoxy is a two-part adhesive — a resin and a hardener that only cure once mixed together — delivering excellent bond strength on metals, ceramics and most rigid substrates, with a genuine ability to bridge gaps other adhesives can't fill.
Getting the mixing ratio right matters more with epoxy than almost any other adhesive: every product has a specific mix ratio by weight, and deviating from it produces a weaker, off-ratio cure. Cure speed is also strongly temperature-dependent — every 10°C drop roughly halves the cure rate — and typical industrial epoxies cover a working range of about -55°C to +120°C.
Read AIMS's full Industrial Adhesive Types Guide →
Shop AIMS's range of adhesives, sealants & tapes →
What Is Epoxy Resin? (Chemical Anchor)
Epoxy resin is the premium resin chemistry available in Chemical Anchor systems, curing to the highest bond strength and the best chemical and temperature resistance of the common chemistries used in anchoring — ahead of both economy polyester and the mid-tier Vinyl Ester Resin above.
That extra performance comes with a slower cure and less tolerance for a damp or poorly cleaned borehole, so epoxy is specified deliberately rather than used as a general-purpose default — heavy structural anchoring, seismic category C2 applications and rebar doweling are the jobs where an engineer calls for epoxy specifically, rather than accepting the faster, more forgiving vinyl ester as good enough. Getting Embedment Depth and borehole cleaning right matters even more with epoxy, since its higher rated loads assume the anchor was installed exactly to spec.
Read AIMS's full Chemical Anchor Guide → for the full resin chemistry comparison
What Is Equipment?
Equipment is the general term for the tools, machinery, apparatus and gear used to carry out work — everything from hand tools and power tools through to fixed plant, vehicles and production machinery.
It's a deliberately broad umbrella term rather than a precise technical one: in a maintenance and procurement context it covers everything MRO activity exists to keep running, and it's the "E" in OEE (Overall Equipment Effectiveness), the standard KPI for how well that equipment is actually performing against its full potential.
What Is an Evaporative Cooler? (Industrial)
An industrial evaporative cooler draws air through water-wetted pads — usually cellulose media — and the evaporation itself drops the air temperature by around 5–12°C before it's pushed into the workspace. It's a genuinely different cooling mechanism to a fan: it actually lowers air temperature rather than just moving air across skin.
The catch is that it only works well in dry climates — its performance is entirely dependent on relative humidity. Inland WA, SA and NT (20–40% RH) see the full 10–15°C drop; humid coastal cities like Brisbane are marginal at best (2–5°C); and tropical conditions in Cairns or Darwin (75–95% RH) see next to no benefit at all. In those humid climates, an HVLS Fan or Mancooler — which move air rather than trying to cool it evaporatively — are the better call. Where an evaporative cooler is the right fit, it needs genuine upkeep: annual water-pad replacement and monthly reservoir cleaning to keep Legionella risk under control.
Read AIMS's full Industrial Cooling Guide →
Shop AIMS's range of HVAC & refrigeration equipment →
What Is an Eye Bolt?
An eye bolt is a bolt with a circular loop (the "eye") in place of a standard head, threaded into a tapped hole to provide a lifting or anchor point. AIMS stocks two distinct types, and they are not interchangeable:
- Plain eye bolt (DIN 580) — rated for vertical, in-line lifting only. Angle-load a plain eye bolt and its rated capacity drops sharply, or it can bend and fail.
- Collared eye bolt (BS 4278) — has a wider bearing collar under the eye, specifically designed to permit angular loading at a rated capacity.
For a lifting point that will regularly be loaded at an angle, a Swivel Hoist Ring — a bearing-mounted fitting rated for full WLL at any angle — is usually the better choice than either eye bolt type. An eye bolt is also a removable, threaded fitting, distinct from a Pad Eye, which is welded permanently to a structure.
Read AIMS's full Eye Bolt Guide → for WLL tables and angular de-rating factors by size
Shop AIMS's range of lifting equipment →
F
What Is an F-Clamp? (Bar Clamp)
An F-clamp — also called a bar clamp — has a long sliding rail with a fixed jaw at one end and a moveable jaw that slides along the rail and locks in place, giving a much greater clamping span than a C-Clamp / G-Clamp's fixed-throat frame allows.
That long reach makes it the standard choice for clamping across a wide panel, holding two boards edge-to-edge for gluing, or spanning a job a C-clamp's frame simply can't reach around — trading some of the C-clamp's raw compact clamping force for span and speed of adjustment along the rail.
Read AIMS's full Clamp Types Guide →
Shop AIMS's range of bar clamps →
What Is FAD? (Free Air Delivery)
FAD is the actual volume of air a compressor delivers, measured at the outlet and converted back to atmospheric conditions, expressed in litres per minute (L/min) — or CFM in older or imported documentation. It's not the same as a compressor's theoretical piston displacement: FAD accounts for real-world losses like valve leakage and ring blow-by, so it's always somewhat lower than the "swept volume" a spec sheet might otherwise imply. In Australia, manufacturers rate FAD to AS 4637.
FAD is the one number that actually predicts whether a compressor will keep up with tool demand — tank size, motor kW and displacement are all secondary to it. Sizing a system correctly means listing every tool that might run at once, summing their individual FAD demands, and adding a 25–30% safety margin before choosing a compressor rated at or above that figure — see Piston Compressor (Reciprocating) and Rotary Screw Compressor for how the two main compressor types differ in sustained FAD output, and Receiver Tank for why tank size doesn't substitute for it.
Read AIMS's full Air Compressor Guide → for the full sizing method and tool-by-tool FAD reference table
What Is a Fan Belt?
Fan belt is the everyday term for the automotive V-belt or serpentine belt that drives an engine's accessories — the fan, alternator and water pump — from a pulley on the crankshaft.
It's functionally the same component covered under V-Belt (Drive Belt) in an industrial context, just applied to a vehicle engine bay rather than a stationary drive — and despite the depth of technical belt coverage elsewhere in this glossary, "fan belt" is a genuinely high-volume everyday search term in its own right that deserves its own plain-English entry. See Top Width (Belt Sizing) for the sizing dimension most relevant to matching a replacement fan belt correctly.
Shop AIMS's range of industrial drive & conveyor belts →
What Is a Fastener?
A fastener is any hardware component used to mechanically join two or more parts together — the umbrella term covering bolts, screws, nuts, washers, rivets, pins, anchors and the huge range of specialty items AIMS stocks across this category.
Fasteners split broadly into two families: threaded fasteners (bolts, screws, nuts, threaded rod — removable, re-tensionable, generally the stronger and more common choice for anything that may need servicing) and non-threaded fasteners (rivets, pins, retaining rings — often permanent or semi-permanent, and typically lighter and faster to install in volume). Selecting the right one comes down to load direction (shear vs tension), whether the joint needs to be removable, the base material, and the environment (corrosion, vibration, temperature).
Shop AIMS's range of fasteners →
What Is Fatigue Strength?
Fatigue strength is the maximum stress a material can withstand for a specified number of load cycles before it fails by fatigue — cracking and eventual fracture caused by repeated loading held well below the material's static tensile strength. It's plotted as an S-N curve (stress against number of cycles to failure), and materials genuinely split into two behaviours on that curve: steel typically shows a real endurance limit — a stress level below which it can theoretically be cycled indefinitely without fatigue failure — while aluminium and most non-ferrous alloys show no true endurance limit and will eventually fail at any stress level given enough cycles, which is why fatigue-critical aluminium components are engineered to a finite service life rather than assumed to last indefinitely the way a correctly-loaded steel part can. See Fracture Point below for how a fatigue failure ultimately ends. *(General engineering fundamentals — no dedicated AIMS article for this term.)*
What Is a Feeler Gauge?
A feeler gauge is a set of thin, precisely-thicknessed steel blades used to measure a gap or clearance by touch, in spaces too narrow for any other measuring tool to fit. AIMS's guide splits the family into blade gauges (flat, hardened steel, suited to valve clearance, piston ring gaps, bearing work and flatness checks on parallel surfaces) and wire gauges (round cross-section, made specifically for spark plug gapping — the round profile seats correctly against a curved electrode, where a flat blade would rock slightly and give a falsely thin reading). Standard automotive/trade sets cover 0.05–1.00mm across 13 blades, with industrial sets extending from 0.02–3.00mm; typical specs to check against include intake valve clearance 0.10–0.20mm, exhaust 0.15–0.30mm, and spark plug gaps 0.6–1.8mm depending on ignition type. See GO/NO-GO Gauge below for the stepped-blade variant used for rapid pass/fail inspection rather than working through a full blade set.
Read AIMS's full Feeler Gauge Guide → for blade vs wire selection and common clearance specs
Shop AIMS's range of feeler gauges →
What Is the FEPA P-Grade Grit System?
FEPA P-Grade is the European grading standard for coated abrasives, written as P80, P120 and so on. It runs alongside the US ANSI/CAMI Grit System rather than replacing it, and the two don't always describe an identical particle size at the same nominal number — a P120 disc and an ANSI/CAMI 120-grit disc from a different supplier can cut noticeably differently. It's worth checking which system a product is graded to before assuming two discs from different brands are directly interchangeable.
What Is Ferrous Metal?
Ferrous means iron-based — steel and cast iron are the two common ferrous materials in general industrial supply, as distinct from Nonferrous.
Ferrous metals are generally magnetic and prone to rust without protection, unlike most nonferrous metals. It's also the basis for one of the most common blade and consumable selections in the trade — cutting discs and blades are usually specified separately for ferrous versus nonferrous material because the two behave very differently under a cutting edge.
What Is Fibreglass Reinforcement Mesh (Cutting Disc)?
Fibreglass reinforcement mesh is a layer of woven fibreglass embedded within a cutting or grinding disc's Phenolic Resin Bond, adding tensile strength so the disc can withstand the centrifugal force of high-speed rotation and the side-loads of cutting without shattering. It's a safety-critical layer, not a filler — a disc missing or with damaged mesh is a discard, not a "keep using it carefully."
What Is a Fifth Wheel Coupling?
A fifth wheel coupling is the horseshoe-shaped, spring-loaded locking plate mounted on a Prime Mover's chassis that a semi-trailer's King Pin slides into and locks onto, forming the pivot point that lets the trailer articulate relative to the truck while transferring a large share of the trailer's loaded weight — its Kingpin Weight — onto the prime mover's own drive axles. The same coupling principle, in a lighter form, is what a Converter Dolly or a Turntable provides further back in a multi-trailer combination.
What Is a Filler Rod? (TIG)
A TIG filler rod is the separate length of bare wire an operator feeds by hand into the Weld Pool / Puddle during TIG (Welding), adding material to the joint — unlike MIG (Welding), where the wire itself is both electrode and filler in one continuously fed strand. Choosing the right rod means matching its alloy to the base metal, not just to the joint's visual finish: the wrong filler can cause porosity, cracking or corrosion that only shows up after the job's already signed off.
The rod naming convention (ER70S-2, ER308L, ER4043 and similar) follows the same "E = electrode, R = rod, first digits = minimum tensile strength" logic used across Filler Rod and MIG wire alike. For mild steel, ER70S-2 is the forgiving, contamination-tolerant general choice; stainless work needs a matching low-carbon "L" grade (ER308L for 304, ER316L for 316) to avoid sensitisation; and aluminium typically runs ER4043 for general fabrication or ER5356 where higher strength or anodising colour match matters. Rod diameter is chosen against material thickness and amperage, and — like any welding consumable — clean, dry storage matters, since a contaminated rod contaminates the weld pool it's dipped into.
Read AIMS's full TIG Welding Guide and Welding Consumables Guide →
Shop AIMS's range of TIG welding rods →
What Is Fine Thread?
Fine thread refers to a component's tighter-pitch thread option at a given nominal diameter — packing more threads into the same length than the standard Coarse Thread at that size.
Fine threads develop slightly higher tensile strength for the same diameter (more thread engagement area), resist vibration-loosening better thanks to their shallower helix angle, and allow finer adjustment — the right call for precision work, thin-walled materials and high-vibration environments. AIMS's own guide notes that fine-pitch metric bolts of the same grade typically need 8–12% higher torque than coarse-pitch equivalents to reach the same clamp force, because the finer threads increase friction.
Read AIMS's full Metric vs Imperial Fasteners Guide → for coarse/fine pitch comparisons across metric and imperial systems
What Is a First Aid Kit?
A first aid kit is a stocked set of supplies and equipment kept on-site to treat injuries and medical emergencies until further care is available. In an Australian workplace, its physical contents are set by AS 2675 (Australia's standard for portable kit content, packaging and marking), but the current, actively enforced reference for how a kit is actually selected, located and maintained is Safe Work Australia's "First Aid in the Workplace" Code of Practice, which AS 2675 alone doesn't cover.
Workplaces are classified into three risk brackets, each needing a different kit: low-risk (offices, retail) needs a standard AS 2675 baseline kit; high-risk (construction, mining, manufacturing, welding) needs that kit plus industry-specific additions and, in some cases, a defibrillator; and remote or isolated sites need a mining-class kit with snake bite and survival supplies added. A baseline kit must be accessible without unlocking doors, clearly marked with the green-and-white AS 1319 first aid sign, mounted at 1.4–1.7 m for easy reach, and located within 30 metres of any worker — inspection follows its own cycle too, from weekly visual checks up to a full annual audit, since content items like saline and dressings have their own expiry windows.
Read AIMS's full First Aid Kit Guide →
Shop AIMS's range of first aid kits & supplies →
What Is Fit Testing? (Respirator)
Fit testing is the formal, documented process of verifying that a specific respirator model and size actually seals correctly against an individual wearer's face — it's a legal requirement for tight-fitting respirators used against hazards like asbestos and silica, not an optional extra.
A respirator that isn't fit-tested to the wearer offers no reliable guarantee of its rated filter performance, since even a small gap around the seal lets unfiltered air bypass the filter entirely. Facial hair, in particular, defeats a tight seal completely — which is exactly why a PAPR with a loose-fitting hood is specified for bearded workers instead.
Read AIMS's full Respirator & Dust Mask Guide →
What Is a Fitting Sleeve (Bearing Drift)?
A fitting sleeve — sometimes called a bearing drift — is a tool used when mechanically pressing a bearing onto a shaft or into a housing, shaped to contact only the ring actually being fitted (inner ring for a shaft, outer ring for a housing bore) rather than bridging both rings or bearing down on the rolling elements. That's the same Interference Fit principle stated the other way around as a tool rather than a rule: apply force to the ring being fitted, never through the rolling elements, to avoid Brinelling the new bearing before it's even in service.
AIMS's own guide is blunt about the common workshop shortcut of using soft brass or aluminium drifts applied by hand around the ring as an emergency substitute: it calls this "a last resort, not a method," since the uneven force risks damaging the shaft shoulder, the bearing seat and the new bearing all at once.
Read AIMS's full Bearing Maintenance: Inspection, Lubrication & Replacement Guide →
What Is Fixture Time?
Fixture time is how long an adhesive takes to reach enough strength to hold a joint together for light handling — the point where parts can be released from a clamp or jig without the bond falling apart. It's a much earlier milestone than Full Cure Time, often ten to a hundred times shorter: Loctite 406 fixtures on plastics and rubber in under 5 seconds but takes 24–72 hours to reach full cure strength.
Confusing the two — putting a joint into full working load right after it's merely fixtured — is a common cause of early bond failure. See Green Strength for the practical bond-strength concept that sits inside this window.
Read AIMS's full Loctite 406 Guide →
What Is a Flange?
A flange is a flat, bolted rim on the end of a pipe, valve or fitting, used to join pipework or connect a valve into a line without welding or threading — a gasket compressed between two mating flange faces provides the seal, and the bolt pattern must match exactly between both sides.
Australian flanges are specified by pressure class under AS 2129, using Table C, D and E designations rather than the American ANSI class system directly — and critically, a Table D flange will not bolt up to a Table E flange of the same nominal pipe size, since their bolt circles and pressure ratings genuinely differ, despite both being common on the same size of pipe. Common types include weld-neck (welded to the pipe, for high-pressure and critical service), slip-on (the pipe slides into the flange bore before welding, easier to align but weaker), and blind (a solid disc with no bore at all, used to seal off the end of a line completely). Getting the flange table, size and bolt pattern all correct before ordering a mating gasket or counter-flange avoids the single most common flange-fitting mistake on-site.
Shop AIMS's range of pipe flanges and flanges & flanged fittings →
What Is a Flanged Bearing Unit (UCFL/UCFB/UCFC)?
A flanged bearing unit is the same insert bearing used in a Pillow Block, mounted instead in a flanged housing for wall or vertical-face mounting rather than sitting flat on a base. AIMS's own guide sets out the common variants: UCF (square flange, four bolts, moderate-to-high load), UCFL (oval flange, two bolts, for space-constrained face mounts at moderate load), and UCFC (round flange, four bolts arranged circularly, for end-of-shaft applications).
Read AIMS's full Pillow Block Bearing Guide: UCP, UCF, UCFL & Plummer →
Shop AIMS's range of bearing housings →
What Is a Flanged Nut?
A flanged nut is a hex nut with an integrated circular flange at its base, built in as a permanent, non-removable washer — spreading clamp load over a wider bearing area than a plain hex nut and, on a serrated flange variant, biting slightly into the mating surface for extra vibration resistance without needing a separate lock washer.
A smooth (non-serrated) flange is the right choice on coated, painted or otherwise finished surfaces where a serrated flange would mark or damage the coating; a serrated flange is the right choice on bare metal where the extra bite genuinely helps resist loosening. AIMS's own types-of-nuts guide covers flanged nuts alongside hex, Nyloc®, castle and dome variants as one of the core nut families.
Read AIMS's full Types of Nuts Guide → for smooth vs serrated flange selection
Shop AIMS's range of flanged nuts →
What Is a Flap Disc?
A flap disc is made up of overlapping abrasive-coated cloth flaps bonded radially to a fibreglass or phenolic resin backing plate — as the outer flaps wear away in use, fresh abrasive is continuously exposed underneath, letting one disc grind and finish in a single operation rather than needing a separate Grinding Wheel pass followed by a finishing pass. It's easy to confuse with a Cutting Disc or a Grinding Disc, but a flap disc trades faster material removal for a smoother finish and less heat and gouging risk — see Type 27 Disc Shape and Type 29 Disc Shape below for its two backing-plate profiles. Typical grit range runs 24–120: coarse (24–60) for weld grinding and heavy rust, medium (60–80) for blending, fine (80–120) for paint or coating prep. A non-woven flap disc swaps the coated-cloth flaps for non-woven (Scotch-Brite®-style) material, trading cut rate for a softer, more conformable blending and finishing action — see AIMS's Non-Woven Abrasive Pad & Disc Guide.
Read AIMS's full Flap Discs Guide → for grit selection and backing plate types
Shop AIMS's range of flap discs →
What Is a Flat Belt?
A flat belt is the original industrial belt-drive design — a plain, flat, rectangular-section belt running over cylindrical, often slightly crowned pulleys rather than the wedge-shaped grooved pulleys a V-Belt (Drive Belt) needs — historically the standard drive method for line-shaft factories, where a single overhead shaft powered dozens of individual machines through flat leather or canvas belting.
Flat belts have largely been superseded by V-belts and timing belts in general industrial service, since a flat belt relies purely on friction and belt tension to transmit torque (no wedging action into a pulley groove), needs a slightly crowned pulley face to track and stay centred rather than walking off sideways, and generally needs a longer, straighter drive layout than a V-belt arrangement of the same power rating. They still turn up in a handful of specialist applications where their advantages matter more than their drawbacks: high-speed drives (a flat belt's thin cross-section handles high surface speeds with less centrifugal loss than a V-belt) and machinery such as bakery equipment, textile mills and some woodworking tools, where a wide, flat contact surface or very smooth, low-vibration running is genuinely useful.
What Is a Flat Head Screw?
A flat head screw is the everyday trade name for a countersunk (CSK) head screw — conical underside, sits flush with the surface once fully seated in a matching countersunk hole — see Countersunk Head above for the angle standards and seating detail.
"Flat head" and "countersunk head" describe exactly the same screw; the two terms are used interchangeably in Australian trade and retail contexts, with "countersunk" more common in engineering documentation and "flat head" more common in general hardware and construction usage.
Read AIMS's full Countersunk Screw Guide → for CSK angles, sizes and selection
Shop AIMS's range of countersunk screws →
What Is Flux Coating? (Stick Electrode)
The flux coating is the layer of mineral and chemical compound wrapped around the metal core of a stick (SMAW / MMA) electrode, which burns off in the arc to shield the weld pool from atmospheric contamination, stabilise the arc and form the protective Slag (Welding) layer over the cooling bead. It's the stick-welding equivalent of the Shielding Gas used in MIG (Welding) and TIG (Welding) — except the shielding is generated by the electrode itself rather than supplied from a separate cylinder, which is exactly why stick welding tolerates wind and outdoor conditions that would blow a gas shield away.
Three flux families cover almost every Australian workshop job. Cellulosic coatings (E6010, E6011) burn with an aggressive, driving arc and fast-freezing slag, built for deep penetration on pipeline and dirty steel. Rutile coatings (E6013, E7014) run a soft, smooth, easy-to-strike arc with lighter penetration — the standard learner and general-fabrication choice. Basic/low-hydrogen coatings (E7016, E7018) trade a slightly harder arc for the best mechanical properties and toughness, but need genuine care: once the packet is opened, low-hydrogen rods need dry, heated storage (50–150°C) and re-baking if left exposed to humid air for more than about four hours, or hydrogen pickup can crack the weld.
Read AIMS's full Stick Welding Guide →
Shop AIMS's range of Gemini stick welding electrodes →
What Is Food Grade Grease (H1 Grease)?
Food grade grease — commonly called H1 grease after its NSF H1 registration — is grease certified safe for incidental food contact, required anywhere standard industrial grease can't be risked near product in food, beverage or pharmaceutical manufacturing. NSF H1 certification applies to the whole formulation (base oil, thickener and additive package together), so an H1-rated grease isn't simply a "food safe" label bolted onto a standard product — it's a genuinely different, ingredient-restricted formulation.
"Food grade" here is a safety certification, not a consistency or viscosity classification — worth distinguishing from NLGI Grade and VG (Viscosity Grade), which describe a grease or oil's physical properties rather than what it's certified safe to contact, per the existing Grade disambiguation note in this glossary.
Shop AIMS's range of greases →
What Is a Forced-Air Convection Heater?
A forced-air convection heater uses combustion or an electric resistance element to heat air, which a fan then blows directly into the workspace — delivering fast, even heat recovery across a large open area rather than the direct, line-of-sight heat of a Radiant Heater (Industrial).
It's the workhorse choice for large open-bay workshops and fabrication shops that need to bring a big volume of air up to temperature quickly, though it loses more heat to ventilation and air stratification than a radiant unit does — warm air rises and pools near the ceiling unless it's actively mixed. Forced-air heaters range from small electric portable units on a Single-Phase Fan/Heater Supply through to large diesel or gas-fired systems (50 kW+) whose fan systems need a Three-Phase Fan/Heater Supply. Where the heater is diesel-fired, it's worth confirming whether it's direct-fired or an Indirect-Fired Diesel Heater — the two aren't interchangeable in an enclosed space.
Read AIMS's full Industrial Heating Guide →
What Is Formwork?
Formwork is the temporary mould — built from formply (timber-based sheet), steel, aluminium or engineered plastic panel systems — that holds wet concrete in its intended shape while it cures, removed once the concrete has gained enough strength to support itself and any load placed on it.
Formwork on its own isn't self-supporting once it's carrying the weight of wet concrete, which is exactly what Shoring below exists to provide — propping and bracing the formwork itself rather than the finished structure. Stripping time is governed by the concrete's actual strength gain rather than a fixed number of days (AS 3610 sets minimum periods based on element type and loading), and Rebar is always placed and checked before formwork is closed up around it, not after.
What Is a Forstner Bit?
A Forstner bit is a woodworking bit that drills a flat-bottomed hole with clean, smooth walls — a centre brad point positions the bit, two outer rim cutters score the hole's perimeter first, and flat cutting wings then scrape the bottom flat, in that order. That perimeter-first scoring is what gives a Forstner bit its defining advantage over an Auger Bit (which cuts faster but rougher) and a spade bit (which tears through the wood fibres and splinters): a Forstner bit produces a genuinely clean, splinter-free result, at the cost of running slower and needing perpendicular entry — tilting a handheld drill causes one cutting wing to bite deeper than the other and produces an angled hole bottom. It's also able to overlap an existing hole or drill a clean, flat-bottomed blind hole, which neither an auger nor a standard twist drill can do. The single most common application in Australian cabinet making is the 35mm European concealed-hinge cup, since every standard European hinge uses that exact recess size.
Read AIMS's full Forstner Bit Guide → for sizing and technique
Shop AIMS's range of Forstner drill bits →
What Is FR? (Flame Resistant / Retardant)
FR stands for flame resistant (or flame retardant) — workwear fabric that self-extinguishes and won't continue burning or melting onto the skin after the ignition source is removed, unlike untreated cotton or synthetic fabric.
FR is genuinely different from AR (arc-rated) protection: all AR garments are FR, but not all FR garments are AR — AR garments are separately tested for arc thermal performance (ATPV, in calories per square centimetre) under IEC 61482/ASTM F1959, which matters for anyone working in an arc-flash zone. General FR workwear suits welding and other sparking environments; explicitly AR-rated workwear, matched to the hazard category, is mandatory for electrical line and substation work. FR fabric also needs specific laundering — bleach destroys the FR treatment immediately, so AS/NZS 4146-compliant industrial laundering is recommended for fleet workwear.
Worth keeping distinct from FRAS (Flame Resistant Anti-Static), a different rating entirely: FR describes a garment fabric's own burn behaviour, while FRAS is a dual fire-resistance-and-anti-static rating applied to belts and other materials — V-belts and conveyor belting in particular — used in coal mining, grain handling and other explosive-dust environments. Related concept, different thing being rated.
Read AIMS's full Work Pants Guide →
Shop AIMS's range of FR & hi-vis workwear →
What Is the Fracture Point?
The fracture point is the stress (or strain) at which a material actually separates and fails completely — the final point on a Stress/Strain curve, distinct from the yield point (where permanent deformation begins) and the ultimate tensile strength (the highest stress the material reaches before it starts to neck down and lose strength ahead of final fracture). *(General engineering fundamentals, lower search priority — no dedicated AIMS article for this term.)*
What Is FRAS? (Flame Resistant Anti-Static)
FRAS stands for Fire (or Flame) Resistant Anti-Static — a dual rating applied to both V-belts and conveyor belting for use in explosive-dust or gas environments, most strictly regulated for underground coal mines under Australian standard AS 4606 and the NSW Resources Regulator's TRG 3608, but genuinely broader than coal mining alone: AIMS's own FRAS range also covers grain handling, woodworking and chemical/petrochemical plant, anywhere flammable dust accumulation is a real risk.
The rating exists because these environments combine two serious ignition risks in one place: a flammable dust or gas atmosphere that a belt fire could ignite, and static discharge from a moving belt that could itself be the ignition source. A FRAS-rated belt is tested and certified against both risks together — one property alone (fire-resistant but not anti-static, or vice versa) doesn't satisfy the standard, and as AIMS's own guide puts it, "all FRAS belts are fire-retardant, but not all fire-retardant belts are FRAS." Standard coal-mining conveyor work in Australia is tested against AS 4606; V-belt and other product FRAS ratings sold internationally may instead reference ISO 1813 (anti-static/conductivity testing), ATEX certification (explosive atmospheres) or IS 2494 Part II (fire resistance) — worth checking which standard a specific FRAS claim is actually certified against, since they're not all measuring exactly the same thing. See FR (Flame Resistant / Retardant) in the Safety & PPE category for the related-but-distinct rating that applies to workwear fabric rather than belts, and Cover Compound (Conveyor Belt) for how FRAS relates to the rest of a conveyor belt's construction.
Read AIMS's full FAQs on FRAS Belts Guide →
What Is a Friction Type Joint (Slip-Critical / Snug-Tightened / Pretensioned Joint)?
A friction type joint (also called a slip-critical joint) is a structural bolted connection designed to transfer load entirely through friction between the clamped steel plates, generated by a fully pretensioned bolt clamping them tightly together — the bolt itself is never intended to bear directly against the sides of the hole in normal service, unlike a Bearing-Type Joint.
Because the whole design relies on friction at the faying (contacting) surfaces, the surface condition matters enormously — mill scale, paint, and galvanising all change the achievable slip coefficient, which is why structural specifications control surface treatment as carefully as bolt tension itself. A "snug-tightened" joint is brought only to firm contact without full pretension (adequate for a bearing-type connection); a "pretensioned" joint is deliberately tightened well beyond snug, to a specified minimum bolt tension, using Angle Controlled Tightening, a calibrated torque method, or a DTI Washer to confirm it.
Read AIMS's full Structural Bolt Tensioning to AS 4100 Guide → for the full tensioning-method and minimum-tension breakdown
What Is Frictional Coefficient (Fastener Context)?
The frictional coefficient, in a bolted-joint context, is a measure of how much resistance a given combination of thread and bearing surfaces generates against rotation for a given clamp force — it's the physical property that the K-Factor / Nut Factor in the torque-to-tension formula is actually trying to capture.
Surface condition dominates this figure far more than material choice alone: AIMS's own torque guide shows K-factor (and therefore required torque for the same clamp force) ranging from around 0.10 on PTFE-coated threads up to 0.35 on corroded threads — meaning a corroded bolt can need more than three times the torque of a well-lubricated one to reach identical actual tension, which is exactly why torque specs always assume a stated thread condition and can't simply be reused across different platings or lubrication states.
Read AIMS's full Metric Bolt Torque Chart → for K-factor by thread condition and the full torque formula
What Is FRL Unit? (Filter-Regulator-Lubricator)
An FRL unit combines three functions in one assembly fitted at the point of use, upstream of a tool or machine. The filter removes particulate, water droplets and oil aerosol via a centrifugal deflector and filter element (typically 5 or 40 micron), draining collected contaminant from a bowl. The regulator drops incoming line pressure down to the tool's working pressure and holds it steady as demand fluctuates. The lubricator injects a fine, controlled oil mist into the airstream via the venturi effect, for tools — air grinders, impact wrenches, rotary tools — that need ongoing internal lubrication to run properly.
Not every circuit needs the lubricator stage: many modern cylinders, valves and solenoids are designed to run unlubricated, and adding oil mist to those circuits does nothing useful. FRLs are sized by port (¼ BSP for one or two hand tools, 3/8 BSP for medium flow, ½ BSP for a high-flow station or tool group) rather than by a single universal size. One habit worth breaking: leaving the regulator wound up to maximum and relying on the tool's own throttle to manage pressure — setting the regulator to the minimum pressure the tool actually needs cuts leakage, compressor wear and downstream seal fatigue all at once.
Read AIMS's full Pneumatic Fittings & Air Line Components Guide → for filter micron ratings and the full FRL maintenance schedule
Shop AIMS's range of compressed air lubricators & FRL units →
What Is a Full Body Harness?
A full body harness is fall-protection equipment worn around the shoulders, torso and legs, with a dorsal D-ring between the shoulder blades as the sole certified fall-arrest attachment point — side and front D-rings, where fitted, are typically rated only for work positioning or ladder assist, not fall arrest, so checking the labelling on each D-ring matters.
Correct leg-strap fit follows the two-finger rule: tight enough that two fingers fit between the strap and the leg, since too loose lets the harness ride up on impact and cause serious groin injury, while too tight restricts movement. A harness has a hard 10-year service limit from its date of manufacture regardless of inspection result, on top of the pre-use check every wearer should do and the six-monthly detailed inspection a competent person should carry out. Suspension trauma is the other real risk to know about: a worker left hanging in a harness after an arrested fall can lose consciousness within about 15 minutes, so a documented rescue plan is mandatory before any work at height begins, not an afterthought.
Read AIMS's full Safety Harness Guide →
Shop AIMS's range of height safety equipment →
What Is Full Cure Time?
Full cure time is how long an adhesive takes to reach its maximum, rated bond strength — often ten to a hundred times longer than Fixture Time, the earlier milestone where a joint can only survive light handling.
Loctite 406, for example, fixtures on plastics and rubber in under 5 seconds but takes 24–72 hours to reach full cure strength. A joint put into full working load before it reaches full cure — rather than merely fixtured — is a common cause of early bond failure.
Read AIMS's full Loctite 406 Guide →
What Is a Full Hex Nutsert? (vs Half Hex)
Full hex and half hex describe how much of a rivet nut's outer body is hexagonal rather than round — a full hex nutsert has a hexagonal shank along its entire length, giving maximum resistance to spinning in the hole under installation or use torque; a half hex nutsert is hexagonal only partway along the body (typically at the flange end), with a plain round shank for the remainder, giving a middle ground between anti-rotation grip and ease of insertion into a plain round hole.
Both sit alongside plain round-body and ribbed/knurled-body rivet nuts as anti-rotation strategies — a plain round body relies purely on expansion friction to resist spinning, which works reliably in steel but is unreliable in softer materials like aluminium, fibreglass or plastic, where a hex or ribbed body is the safer choice. *(General fastening-industry terminology — no dedicated AIMS article distinguishing full hex from half hex specifically, though it sits within AIMS's broader rivet nut body-type coverage.)*
Shop AIMS's range of rivet nuts & nutserts →
What Is a Full-Bore Valve?
A full-bore valve has an unobstructed flow path equal to the pipe's own internal diameter when fully open — as opposed to a reduced-bore (or reduced-port) valve, which is one size smaller through the valve body than the connecting pipe.
Full bore matters for two practical reasons beyond simply lower flow resistance: it allows pigging (running a cleaning or inspection tool through the line without the valve itself creating an obstruction), and it avoids the velocity increase a reduced bore creates at the same flow rate, which matters for erosion-prone or cavitation-sensitive media. The trade-off is cost and size — a full-bore valve is physically larger and more expensive than a reduced-bore valve of the same nominal pipe size, which is why reduced-bore remains the default for general-purpose isolation duty where pigging and velocity aren't a concern.
Read AIMS's full Ball Valve Guide and Gate Valve Guide →
G
What Is a G-Clamp?
A G-clamp is the AU/UK name for the same screw-driven frame clamp called a C-Clamp in American usage — "G" describing the clamp's frame shape when open, much the way "C" describes it in the American name.
Both names describe the identical tool and are used interchangeably in Australian trade conversation, though "G-clamp" is the more common term on AIMS's own product listings and in general AU trade speech.
Read AIMS's full Clamp Types Guide →
What Is Galling (Thread)?
Galling is a form of severe adhesive wear where friction and pressure between two mating thread surfaces cause localised cold-welding — material is torn from one surface and transferred to the other — seizing the fastener partway through installation or removal, often to the point of destroying both parts.
Stainless steel and other self-passivating alloys are especially prone to galling because the thin oxide layer that protects them from corrosion is easily disrupted by friction, exposing bare metal that welds to the mating thread almost instantly under load — which is why anti-seize compound or thread lubricant is routinely specified for stainless-on-stainless fastening, and why AIMS's own thumb-screw guide flags anti-seize as mandatory for stainless-on-stainless applications. Once galling has started, backing the fastener out generally makes it worse rather than better, since the torn material re-engages on every turn. *(General engineering fundamentals, cross-referenced against AIMS's stainless fastener and thumb screw guides — no single dedicated AIMS article on galling itself.)*
What Is a Gap-Filling Adhesive? (Gel)
A gap-filling adhesive is a thickened, gel-viscosity formulation designed to bridge uneven, vertical or overhead joint surfaces without running or sagging the way a standard low-viscosity liquid adhesive would.
Loctite 454, for example, is rated to bridge gaps up to 0.25 mm — larger than a standard liquid cyanoacrylate can reliably fill — with an operating range of -54°C to +121°C, at the cost of a slower fixture time on some substrates (60–210 seconds on steel, versus single-digit seconds for a standard liquid CA). It's the right choice for porous materials, loose-fitting joints and any application where the part can't be clamped tightly enough to control a runny liquid adhesive.
Read AIMS's full Loctite 454 Guide →
What Is a Gas Detector?
A gas detector is a device that monitors the surrounding atmosphere for hazardous conditions — a combustible or toxic gas above its safe exposure limit, or an oxygen level outside the safe 19.5%–23.5% band — and gives an audible and visual alarm before a worker is exposed to a dangerous atmosphere.
Single-gas detectors monitor one specific hazard (commonly oxygen, carbon monoxide or hydrogen sulphide) and are typically worn as a compact personal clip-on unit; multi-gas detectors combine several sensors — most commonly oxygen, combustible gas (LEL), carbon monoxide and hydrogen sulphide together — into one handheld or wearable unit, and are the standard tool specified for Confined Space Entry under AS 2865, where the atmosphere must be tested and continuously monitored before and during entry, not just checked once at the doorway. Getting the detector's own calibration current matters as much as carrying one at all: a gas detector that hasn't been bump-tested or calibrated to schedule can give a false all-clear, which is exactly the failure mode confined space atmospheric testing exists to prevent.
What Is a Gasket Sealant?
A gasket sealant (also called a gasket maker or liquid gasket) is a paste or liquid applied directly to a mating surface that cures in place to form a seal, rather than a pre-cut solid gasket being fitted between the two faces.
The two dominant chemistries are Anaerobic Gasket Maker and RTV silicone, each suited to a different type of joint. Gasket sealants are chosen by temperature range, chemical resistance (oil, fuel, coolant) and whether the joint needs to flex or stay rigid.
Read AIMS's full RTV Silicone & Gasket Maker Guide →
Shop AIMS's range of gasket sealants →
What Is a Gate Valve? (Wedge / Knife / OS&Y)
A gate valve is a multi-turn, full-bore isolation valve that raises or lowers a flat gate across the flow path — built purely for on/off duty, with near-zero pressure drop when fully open, and never intended to throttle.
Four wedge geometries cover most industrial gate valves: solid wedge (simplest, but binds under thermal cycling), flexible wedge (a single-piece gate with a machined slot allowing independent flex — by far the most common type on commodity industrial gate valves), split wedge (self-aligning halves that jam in dirty service), and parallel disc (spring-forced flat discs, limited to low-pressure water). A knife gate valve is a distinct variant with a thin, sharp-edged blade rather than a wedge, purpose-built to cut through fibrous solids, pulp and slurry that would otherwise jam between a standard wedge and seat — but it runs at a genuinely lower pressure rating (typically ANSI 150) because the blade itself is thin. OS&Y (outside screw and yoke) is the end-connection configuration mandatory on fire sprinkler riser isolation valves, since its exposed, rising stem shows open/closed position visibly at a distance — see Rising Stem Valve and Non-Rising Stem Valve for the fuller distinction. Throttling a gate valve — running it part-open to control flow — destroys the gate and seat through cavitation within weeks to months; above roughly 1–2 bar pressure drop across a part-open gate, cavitation becomes the dominant damage mechanism, and below that threshold the gate still vibrates and scours the seat.
Read AIMS's full Gate Valve Guide →
Shop AIMS's range of pipe fittings →
What Is GCM (Gross Combination Mass)?
GCM is the maximum permitted mass of an entire combination — the prime mover plus every trailer coupled to it, fully loaded — as rated by the vehicle manufacturer or approved under a PBS assessment. It's the combination-level counterpart to GVM, which applies to a single vehicle on its own; a road train's GCM has to account for every trailer in the string, not just the towing unit.
What Is GD&T (Geometric Dimensioning & Tolerancing)?
GD&T is a system of symbols, rules and conventions for specifying the geometry of a manufactured part — going beyond a simple plus-or-minus dimension to specify how a feature must be shaped, oriented and positioned, not just its size. The functional case for it is concrete: a hole drilled at the correct coordinates but tilted out of perpendicular to the surface will pass a coordinate-only inspection yet still refuse a press-fit pin — a defect plain ± tolerancing misses entirely, but GD&T catches. The 14 symbols split into five categories: form (4 symbols — straightness, flatness, roundness, cylindricity — controlling shape in isolation, no datum required); orientation (3 — perpendicularity, parallelism, angularity — controlling angle relative to a datum); location (3 — position, concentricity, symmetry — controlling position relative to a datum reference frame); profile (2 — line and surface — controlling irregular features); and runout (2 — circular and total — controlling surface deviation during rotation, always relative to a datum axis; see Runout below). Three standards coexist on Australian drawings — ASME Y14.5 (US-origin, common in aerospace/automotive/defence), ISO 1101 (international, European-aligned) and AS/NZS 1100.201 (the local standard, which adopts ISO conventions but permits either style) — so the drawing's title block, not assumption, determines which convention actually applies.
Read AIMS's full GD&T Symbol Cheat Sheet → for all 14 symbols explained, and the Engineering Drawing Symbols Guide → for the wider drawing-symbol set
What Is a Girder Clamp?
A girder clamp is a fitting that clamps directly onto the bottom flange of a steel beam to create a fixed overhead lifting or anchor point, without needing to weld or drill the structure. It's the fixed-point counterpart to a Beam Trolley, which travels along the beam rather than clamping to one spot — the right choice depends on whether the load needs to move along the beam's length or just needs a solid point to hang from.
Read AIMS's full Beam Clamp Guide → for clamp WLL by flange width
Shop AIMS's range of clamps →
What Is a Glad Hand?
A glad hand is the quick-connect coupling fitted to the end of a heavy vehicle's air brake hoses, letting a driver join and disconnect a trailer's Air Brake System to the towing vehicle's supply quickly and without tools — the two halves (service and emergency lines) are shaped to lock together with a quarter-turn and seal with a rubber gasket. A leaking or poorly seated glad hand is a common roadside brake-fault finding, since it lets air escape from the system that the Slack Adjuster and Brake Chamber rely on.
What Is a Globe Valve?
A globe valve is a linear-motion valve with a spherical body cavity divided by a horizontal seat ring — a disc on a rising stem lifts straight up off the seat to modulate flow, forcing the fluid through two 90° direction changes on its way through the valve.
That double direction-change is precisely what makes a globe valve excel at throttling: it delivers flow proportional to stem lift across most of its travel range, giving smooth, predictable control — where a Butterfly Valve or Ball Valve goes from heavily-throttled to essentially wide-open somewhere between 50% and 70% open, a globe valve's flow response stays controllable and gradual the whole way. The trade-off for that control is a genuinely higher permanent pressure drop even when fully open, compared to a Gate Valve or Full-Bore Valve's near-zero drop — which is exactly why the two valve types have a firm, symmetric rule between them: globe valves are for throttling and should never be run on/off, gate valves are for on/off and should never be throttled.
Read AIMS's full Globe Valve Guide →
Shop AIMS's range of pipe fittings →
What Are the Glove Leather Grades? (Cowhide, Goatskin, Pigskin, Elkskin, Deerskin)
Welding and heavy-duty work gloves are selected by leather grade as much as by cut or heat rating, since each hide type trades off heat resistance, dexterity and durability differently. Cowhide gives high heat resistance with medium dexterity, making it the standard choice for MIG and light stick welding. Goatskin is the dexterity leader — its natural lanolin keeps it supple even after repeated heat cycling — and dominates premium TIG glove construction. Deerskin has the highest tactile sensitivity of any option, favoured for fine pipe and precision TIG work, at the cost of durability. Pigskin resists hardening after repeated wet/dry cycles, making it a good choice for outdoor or marine welding. Elkskin is the highest-heat-resistance leather commonly used, reserved mostly for foundry and blacksmith work rather than standard welding.
The practical process-by-process pairing: TIG favours goatskin or deerskin for maximum dexterity; MIG favours cowhide for a balance of heat/spatter protection and workability; and Stick (SMAW) welding, needing maximum sustained heat protection, favours heavier split cowhide or elkskin.
Read AIMS's full Welding Gloves Guide →
Shop AIMS's range of hand protection →
What Is GMAW? (Gas Metal Arc Welding)
GMAW — Gas Metal Arc Welding — is the formal AWS engineering designation for the process that almost every Australian tradesperson simply calls MIG (Welding). It's the same process under two names: a continuous solid wire electrode, fed automatically through a torch, fusing the joint under a Shielding Gas envelope that keeps oxygen and nitrogen out of the weld pool.
The two names split by context rather than by anything technical — "GMAW" shows up on welding procedure specifications, AWS/AS standards documentation and welder qualification paperwork (per AS/NZS 2980), while "MIG" is what's printed on the machine, said on the shop floor and typed into a search bar. Both point to the identical process, running the identical DCEP / DCEN (Welding Polarity) setup and the identical shielding-gas logic — there's no reason to treat them as different techniques, just different registers of the same term.
Read AIMS's full MIG Welding Guide and MIG vs TIG vs Stick Welding Guide →
Shop AIMS's range of MIG welders and MIG wire →
What Is GML / HML (General / Higher Mass Limits)?
GML (General Mass Limits) are the standard, default axle-group and combination mass limits that apply to a heavy vehicle without any special accreditation. HML (Higher Mass Limits) allow a heavier load on the same vehicle — typically several tonnes more per axle group — but only where the vehicle is fitted with certified road-friendly suspension and the operator holds the relevant mass-management accreditation, since the higher limits are only considered safe for road infrastructure under those extra conditions.
What Is a GO / NO-GO Gauge?
A GO/NO-GO gauge is a two-ended inspection gauge that gives a fast pass/fail check against a tolerance band without needing to read a measured figure at all: the GO end must fit (or pass) — confirming the part meets the minimum acceptable size — and the NO-GO end must refuse to fit (or pass) — confirming it isn't oversized. Both conditions passing means the part is within tolerance; either one failing means rejection. The principle turns up across several distinct gauge families AIMS stocks: pin and plug gauges (a GO end that must enter a hole and a NO-GO end that must not), and stepped feeler gauges (a thinner GO blade that must pass through a gap and a thicker NO-GO blade that must not) — see Feeler Gauge above for that variant. It's a production and quality-control tool by design: rapid inspection without working through a full graduated gauge set on every part.
Read AIMS's full Pin & Plug Gauge Guide → for gauge classes and the GO/NO-GO sizing example
What Is a GPO (General Power Outlet)?
A GPO (General Power Outlet) is the standard Australian term for a mains power point — the wall or panel-mounted socket outlet a plug connects to, built to the AS/NZS 3112 plug and socket-outlet standard that gives Australia and New Zealand their distinctive three-flat-pin plug shape. "GPO" is used interchangeably with "power point" in AU trade and industrial contexts, and the standard covers everything from the everyday 10A domestic outlet up through higher-current industrial variants.
What Is a Grab Hook?
A grab hook is a fixed hook — no spring latch — welded or fitted to a chain sling, designed to grip a chain link so a rigger can shorten a sling leg on site by "grabbing" a link partway along its length. Unlike a Shortening Clutch, which locks the chain in a smooth housing, a grab hook is a simpler, lower-cost fitting most often used on the bottom terminal of a sling rather than for fine mid-leg adjustment.
What Is Grade? (Fastener)
Fastener grade is the standardised strength classification stamped or marked on a bolt, screw or nut, identifying its tensile and yield strength so it can be matched correctly to the load the joint needs to carry — see Property Class below for the full metric numbering system (4.6 through 12.9) and how the two numbers are read.
This is one of four genuinely distinct senses of the word "Grade" already tracked across AIMS's glossary — fastener grade, general steel grade, abrasive grit/bond grade, and (new, surfaced in the Cutting Tools & Machining category) ISO 513's carbide-grade classification — each needing its own entry rather than one merged definition.
Read AIMS's full Bolt Grade Chart → for metric, imperial and stainless grade markings side by side
What Is Grease?
Grease is a semisolid lubricant made from a base oil, a thickener and a package of additives — formulated to lower friction between moving parts and keep water and contaminants out of the system, unlike a straight oil which simply flows away. AIMS's own guide breaks the composition down by proportion: base oil is 75–95% by weight and does the actual lubricating; the thickener (3–30%) is what holds that oil in place and largely determines the grease's temperature range and compatibility with other greases; and additives (1–10%) tune specific properties such as EP Additive performance, anti-wear, oxidation resistance and corrosion protection.
Selecting a grease means matching both the thickener chemistry (see Lithium Grease / Lithium Complex Grease, Polyurea Grease, Calcium Sulfonate (Complex) Grease, Aluminium Complex Grease and Clay (Bentone) Grease below) and the NLGI Grade consistency to the application — get either wrong and the grease can fail even if the other is correct.
Read AIMS's full Grease Selection Guide: Types, NLGI & EP →
Shop AIMS's range of greases →
What Is Grease Compatibility (Thickener Mixing)?
Grease compatibility is whether two greases with different thickener chemistries — Lithium Grease, Polyurea Grease, Calcium Sulfonate (Complex) Grease, Clay (Bentone) Grease and others — can safely be mixed during relubrication without the mixture breaking down. Several common combinations genuinely can't: lithium and polyurea in particular produce a liquid mixture with no useful film strength rather than simply blending, which is a real bearing-failure risk rather than a theoretical one.
The practical rule AIMS's own material gives: don't assume compatibility, and purge old grease out completely when switching thickener type on a piece of equipment rather than simply topping up the new grease over the old.
Read AIMS's full Grease Selection Guide: Types, NLGI & EP →
What Is a Grease Nipple (Grease Fitting)?
A grease nipple (grease fitting, Zerk fitting) is a small, one-way check-valve fitting threaded or pressed into a bearing housing, allowing a grease gun to inject fresh grease under pressure while blocking it from flowing back out — the standard interface point for manual lubrication across almost all rotating and sliding industrial equipment.
Getting the thread standard right matters more here than with most fasteners, because several look nearly identical but aren't interchangeable: AIMS's own guide flags 1/8" BSP (28 TPI, parallel) as visually near-identical to 1/8" NPT (27 TPI, tapered) — threading an NPT fitting into a BSP-tapped hole can strip the host casting permanently, so the recommended check is to hand-thread at least three turns without resistance before ever reaching for a wrench. Metric (M6×1 to M10×1.5) covers most modern European OEM equipment, and 1/4"-28 UNF covers most US-origin machinery.
Read AIMS's full Grease Nipple & Zerk Fitting Guide → for the complete thread-standard identification guide
Shop AIMS's range of grease nipples →
What Is Green Strength? (Adhesive)
Green strength is the bond strength an adhesive has reached before it's fully cured — enough to hold a joint together and resist light handling, but well short of the adhesive's maximum, fully cured strength.
It's a practical, on-the-tools concept: a joint with adequate green strength can usually be moved or lightly loaded without falling apart, but shouldn't be put into full service until full cure is reached. See Fixture Time and Full Cure Time for the two milestones that bracket this.
What Is a Grinding Disc?
A grinding disc is a thicker bonded abrasive wheel built to take lateral load, removing material faster than a Flap Disc but leaving a rougher surface that needs further finishing. It's easy to confuse with a Cutting Disc, but the two aren't interchangeable — a cutting disc is thin and rated for parting cuts only, and shatters under the side pressure a grinding disc is built to handle.
What Is a Grinding Wheel?
A grinding wheel is a general-purpose Bonded Abrasive wheel run on a bench grinder or angle grinder to remove material, shape an edge or sharpen a tool. Common abrasive types include aluminium oxide (steel and HSS work — white aluminium oxide runs cooler and is preferred for heat-sensitive sharpening), silicon carbide (green for carbide tooling, black for non-ferrous metals and cast iron — never run a standard aluminium oxide wheel on carbide, it glazes and overheats), and CBN for woodworking tool sharpening, which holds its shape indefinitely without dressing. Every wheel mounts between matching flanges at least a third of the wheel's diameter, and must pass a Ring Test before its first use on the machine.
Shop AIMS's range of grinding wheels & accessories — AS 1788 →
What Is a Grinding Wheel Spec Code (ISO 525 / AS1788)?
A grinding wheel spec code is the alphanumeric string printed on every bonded wheel — governed by ISO 525 and AS 1788 — that specifies, in a standard sequence, the abrasive type, grain size, grade (see Wheel Grade / Hardness), structure and Bond Type in one compact reference. Reading it correctly is how a buyer confirms a replacement wheel genuinely matches the original, rather than just looking similar.
What Is Grip Length?
Grip length is the length of a bolt's unthreaded shank — the plain, unthreaded section immediately under the head — and it needs to roughly match the combined thickness of the material stack being clamped, so the shank (not the threads) sits across the joint interface where shear load is carried.
Getting grip length right matters most in shear-loaded (bearing-type) joints: if the thread runs into the shear plane because the grip length was too short for the stack thickness, the joint loses strength, since threads have a smaller effective cross-section than the plain shank. See Grip Range and Max. Grip / Min. Grip below for the equivalent concept as it applies to blind rivets and rivet nuts rather than bolts. *(General engineering fundamentals — no dedicated AIMS article for this specific bolt-selection concept.)*
What Is Grip Range (Nutsert / Rivet)?
Grip range is the span of panel (or material stack) thickness a specific blind rivet or rivet nut is designed to clamp reliably — sized too far under the minimum, the fastener won't set properly and spins loosely; sized too far over the maximum, the installation tool can't pull the mandrel far enough and it strips before setting.
AIMS's own guide gives a worked example: an M6 rivet nut has a standard grip range of roughly 0.5–3.5 mm, and the practical rule is to measure the total thickness of everything being clamped, then select the fastener whose grip range comfortably covers that figure — landing in the middle of the range, rather than right at either edge, gives the most consistent set and pull-out strength. See Max. Grip / Min. Grip below for the two boundary figures that define this range.
Read AIMS's full Rivet Nut Guide → for grip range tables by size
What Is a Grommet?
A grommet is a ring — usually rubber, nylon or metal — inserted into a hole cut through sheet material to protect a cable, hose or wire from the sharp edge of the hole, and in some designs to seal against dust and moisture.
Grommets are a protection fastener rather than a joining fastener: they don't hold two parts together, they protect whatever passes through the hole from chafing against it. They're commonly confused with Rivnut/Rivet Nut style inserts, which look similar but serve a completely different purpose (creating a threaded hole, not protecting a cable pass-through).
Shop AIMS's range of cable management →
What Is Grout? (Structural)
Structural grout is a high-strength, typically low-shrink or non-shrink material — cementitious or epoxy-resin-based — placed or pumped under baseplates, bearing plates, crane rails and machinery bases to transfer load evenly from the equipment into its concrete foundation, filling the gap left for levelling during installation.
Epoxy grout is the standard choice wherever the base is carrying dynamic load or continuous vibration — pump bases, compressor foundations, gearbox plinths and crane rails all specify it over a cementitious grout, because it resists the fatigue and micro-cracking that vibration causes in a purely cement-based system over time. It uses the same underlying resin-bond principle as a Chemical Anchor, just placed in bulk under a baseplate rather than injected around a single dowel in a drilled hole.
Shop AIMS's range of Epirez epoxy grouts & floor coatings →
What Is GST? (Goods and Services Tax)
GST is Australia's Goods and Services Tax — a broad-based 10% tax applied to most goods and services sold or consumed in Australia, introduced in 2000 and collected by businesses on the Australian Taxation Office's behalf at each step of the supply chain.
For trade and procurement, a few practical points matter most: businesses with turnover over the ATO's registration threshold must register for GST and charge it; displayed and quoted prices to consumers must be GST-inclusive under Australian Consumer Law; and a registered business can generally claim back GST paid on business purchases as an input tax credit, provided it holds a valid tax invoice (required for any purchase over $82.50 including GST). GST-inclusive and GST-exclusive pricing is one of the most common sources of confusion on trade quotes and purchase orders, so it's always worth confirming which basis a price is quoted on before comparing suppliers.
What Is GTAW? (TIG Welding)
GTAW — Gas Tungsten Arc Welding — is the formal AWS engineering designation for the process every Australian workshop calls TIG. It's the same process under two names: a non-consumable tungsten electrode sustaining the arc, a hand-fed Filler Rod (TIG), and an inert Shielding Gas envelope — almost always pure argon — keeping the weld clean.
As with MIG/GMAW, the split is one of context, not technique: "GTAW" is what appears on AWS specifications, AS/NZS 2980 welding procedure documentation and formal welder qualification records (AS/NZS ISO 9606-1), while "TIG" is the name used on the machine, on the shop floor and in the overwhelming majority of trade searches. The identical Tungsten Electrode Colour Code (AWS A5.12) rules, AC/DC polarity logic and shielding-gas requirements apply regardless of which name is used.
Read AIMS's full TIG Welding Guide →
Shop AIMS's range of TIG welding rods →
What Is GTM (Gross Trailer Mass)?
GTM is the mass actually carried by a trailer's own axles once it's coupled to a towing vehicle — it excludes whatever share of the load is transmitted through the coupling (the Kingpin Weight on a semi-trailer, or the towball/drawbar load on a Pig Trailer / Dog Trailer) onto the towing unit instead. It's always lower than the trailer's ATM, since ATM assumes the trailer is carrying its full rated load entirely on its own axles, uncoupled.
What Is GVM (Gross Vehicle Mass)?
GVM is the maximum total mass a single vehicle is rated to carry — its own tare weight plus fuel, driver, fittings and payload — as set by the manufacturer and confirmed against its axle-group ratings. It applies to one vehicle standing alone; once that vehicle is towing a trailer, the combination is instead limited by GCM, which covers the towing vehicle and everything behind it together.
H
What Is a Hacksaw?
A hacksaw is a hand saw with a thin, replaceable blade held under tension in a C-shaped frame, purpose-built for cutting metal, plastic and other hard materials a woodworking hand saw isn't suited to.
Blade selection is the single biggest factor in how well a hacksaw cuts: a fine, high-TPI (teeth-per-inch) blade suits thin sheet and tube, where at least three teeth need to be in contact with the material at all times to avoid the teeth catching and stripping; a coarser, low-TPI blade cuts faster through thicker, softer material but leaves a rougher finish. Matching blade material to the workpiece matters just as much — a bi-metal blade combines a flexible spring-steel back with hardened high-speed-steel teeth, giving both the durability to survive rough handling and the edge hardness to cut genuinely hard material, which a cheaper carbon-steel blade can't match on anything beyond mild steel.
Read AIMS's full Hacksaw Blade Guide →
What Is a Hand File?
A hand file is a hardened steel bar with a pattern of cutting teeth (its "cut") along one or more faces, used to manually remove small amounts of material for shaping, deburring or finishing a workpiece — slower and more controllable than a power tool for fine finishing work.
File cut ranges from coarse (bastard cut, for fast stock removal) through second cut to smooth (fine finishing work), and file shape is matched to the job — flat, half-round, round, triangular and square sections each suit a different profile of work. A file's teeth cut in one direction only (typically the forward stroke), so applying pressure on the return stroke both dulls the teeth faster and does no useful cutting.
Read AIMS's full Hand File Guide →
Shop AIMS's range of hand files & file sets →
What Is a Hard Hat? (Safety Helmet)
A hard hat is rigid head protection worn to guard against falling objects and impact, certified in Australia under AS/NZS 1801:2024, which sets out four helmet types by application: Type 1 for general construction, manufacturing and warehousing; Type 2 for high-temperature environments like foundries and steelworks; Type 3 for bushfire and wildland firefighting; and the newer Type 4, offering multi-directional impact protection, though not yet commercially available in Australia.
Electrical protection is a separate rating — Class E helmets are tested to withstand 20,000 V AC, but only in a non-vented shell, since any ventilation holes defeat the electrical protection entirely. Service life is capped regardless of visible condition: a maximum of three years from the date of issue (recorded on an internal sticker, not the manufacture date), and unissued stock more than five years past its manufacture date shouldn't be issued at all. Any significant impact — even with no visible shell damage — is an immediate replacement trigger, as is any cracking, deformation, or frayed or hardened suspension webbing.
Read AIMS's full Hard Hat Guide and Hard Hat Colours guide →
Shop AIMS's range of hard hats →
What Is Hardenability?
Hardenability is how deeply and evenly a steel can be hardened right through its cross-section when quenched — it's not the same thing as hardness itself, which is a surface or point measurement.
A thin, simple carbon steel part might harden all the way through easily, while a thick section of the same steel might only harden a shallow layer near the surface, leaving a softer core. Alloy additions (chromium, molybdenum, manganese) are what improve hardenability, letting thicker sections harden more evenly — one of the practical reasons alloy steels like 4140 are chosen over plain carbon steel for larger shafts and gears.
What Is Hardness (General)?
Hardness is a material's resistance to localised plastic deformation, generally measured by pressing a hard indenter into the surface under a known load and measuring the size or depth of the resulting indentation — the smaller the mark for a given load, the harder the material. Three scales cover almost everything AIMS deals with day to day: Brinell (HB), which measures indent diameter under a heavy load and suits coarse or non-uniform materials like castings and welds; Rockwell (HRB/HRC), which measures indent depth directly and is the fast, standard shop-floor method for finished steel parts and fasteners; and Vickers (HV), which measures the diagonal of a diamond-pyramid indent and is used for thin sections, case-hardened layers and microhardness work. Conversions between scales exist (per ASTM E140 and ISO 18265) but are approximate and degrade outside the mid-range — a hardness reading should always specify which scale it was taken on, since a bare number without a scale (e.g. "58" with no HRC/HB/HV) is meaningless. See each scale's own entry below for indenter, load and standard detail.
Read AIMS's full Hardness Testing Guide → for the full scale, indenter, load and standards comparison
What Is a Hasp (Hasp and Staple)?
A hasp (hasp and staple) is a hinged metal fitting with a slotted loop that folds down over a fixed staple (loop) mounted on the opposing surface, creating a fixing point for a padlock across a door, gate, container or cabinet — the loop and staple together form the securable closure a padlock passes through.
Hasps are sized and rated by their steel thickness and hinge/pin construction rather than by a thread standard, since they're a security hardware item rather than a threaded fastener — heavier-gauge, concealed-hinge hasps resist being pried or unscrewed from the accessible side, which is the main design differentiator between a basic hasp and a genuinely security-rated one. *(General hardware terminology — no dedicated AIMS article specifically on hasps.)*
Shop AIMS's range of hasps →
What Is a Hazardous Area?
A hazardous area is a location where an explosive or flammable atmosphere — gas, vapour, mist or combustible dust — could be present in a concentration that requires special precautions for electrical equipment and other ignition sources.
Fuel depots, spray-paint booths, grain silos and chemical storage areas are typical hazardous areas. Equipment used in them (lighting, switches, motors) must be specifically rated and certified for the zone classification involved — ordinary industrial equipment isn't automatically safe to use there, even if it looks robust.
What Is HDG? (Hot Dip Galvanised)
HDG is the standard abbreviation for Hot Dip Galvanizing / hot dip galvanised — see that entry above for the process, coating thickness and service-life detail.
What Is Hearing Protection?
Hearing protection is any device — earplugs or earmuffs — worn to reduce the level of noise reaching the ear, rated in Australia under AS/NZS 1270 using the SLC80 class system rather than the American NRR figure often printed on imported products.
Foam earplugs achieve the highest attenuation when correctly fitted (roll into a thin cylinder, pull the outer ear up and back, insert deeply, then hold for 20–30 seconds while the foam expands), but a poorly fitted earplug can deliver as little as 30–50% of its rated protection — fit technique matters as much as the class rating itself. Earmuffs are simpler to fit correctly and don't require ear-canal insertion, but their seal can be broken by glasses temple arms, which can cut attenuation by 5–15 dB — enough to drop a Class 4 earmuff to effectively Class 2 performance. Above 105 dB(A) LAeq,8h, double protection (earplugs plus earmuffs together) is recommended, though the combined SLC80 isn't simply additive — it's estimated as the higher individual SLC80 plus 5 dB.
Read AIMS's full Hearing Protection Guide →
Shop AIMS's range of ear protection →
What Is Heat Shrink Tubing?
Heat shrink tubing is a flexible plastic sleeving that shrinks tightly around a cable, wire joint or terminal when heated, providing insulation and mechanical protection at the join. It's a standard finish for a soldered or crimped electrical joint, sized to the cable diameter before heat is applied since it only shrinks — it can't be stretched back out afterwards.
Two things determine which tubing is right for the job: shrink ratio and wall type. 2:1 ratio (shrinking to half its expanded diameter) covers most general electrical work and comes in the widest range of sizes and colours; 3:1 ratio handles bigger step-downs in diameter and is the standard choice for dual-wall adhesive-lined tubing; 4:1 ratio is reserved for large diameter changes or heavy industrial/mining cable repairs. Separately, single-wall tubing (standard cross-linked polyolefin, rated roughly -55°C to +135°C, flame-retardant and non-toxic when burned) gives insulation and mechanical protection but no moisture seal, tied to its Dielectric Strength rating for the voltage class it's used at; dual-wall (adhesive-lined) tubing has an inner layer that melts and flows during heating to form a genuine waterproof seal at the join, and is the one to reach for on marine work, battery terminals, outdoor splices or anything in an engine bay or wash-down area. As a sizing rule, pick tubing with an expanded diameter at least 20–30% larger than the cable for easy sliding, and a recovered (shrunk) diameter smaller than the cable for a firm grip once it's heated.
Read AIMS's full Heat Shrink Tubing Guide → for the complete ratio and sizing tables
Shop AIMS's range of heat shrink tubing →
What Is Heat Treating?
Heat treating is the umbrella term for controlled heating and cooling processes used to change a metal's mechanical properties — hardness, strength, ductility or internal stress — without changing its shape or composition.
Annealing, Austenizing, Quenching / Tempering / Normalizing and Stress Relieving are all specific heat-treating processes, each aimed at a different outcome (softening, preparing for hardening, hardening, or relieving stress). Heat-treated fasteners and components — most high-tensile bolts, for example — rely on these processes to reach their rated strength.
What Is Hexavalent Chromium? (Welding Fume Hazard)
Hexavalent chromium is a carcinogenic compound present in the fume generated when welding stainless steel and other chromium-bearing alloys — a distinct hazard from general welding fume, driving its own, stricter respirator and ventilation requirements over and above standard welding fume controls.
Because it's specific to chromium-bearing materials rather than welding fume in general, the correct Respirator Filter Class and ventilation setup for stainless steel welding can genuinely differ from what's adequate for mild steel work on the same job site — treating all welding fume as equivalent is a real compliance and health risk, not just an oversimplification.
Shop AIMS's range of respiratory protection →
What Are the Hi-Vis Classifications? (Class D / Class N)
Australian high-visibility garment classification under AS/NZS 4602.1 is built around two independent elements: the amount of fluorescent background material (Class D or Class N, referring to daytime and night-time use respectively) and, separately, the amount and configuration of retro-reflective tape.
A garment can be rated for daytime visibility, night-time visibility, or both, and the retro-reflective tape configuration (which determines how visible the wearer is under vehicle headlights at night) is what actually separates a genuine night-rated garment from a daytime-only one with similar-looking fluorescent colour. Choosing hi-vis by colour alone, without checking the class rating for the actual working conditions, is a common and avoidable compliance gap.
Read AIMS's full Hi-Vis Vest Guide →
Shop AIMS's range of hi-vis workwear →
What Is the Hierarchy of Controls?
The hierarchy of controls is the ranked order of risk-control methods under Australian WHS law, from most to least effective: elimination, substitution, engineering controls, administrative controls, and — last — personal protective equipment.
The ranking matters because PPE is the weakest control in the hierarchy: it protects the individual wearer only, depends entirely on correct fit, use and maintenance, and does nothing to reduce the hazard itself. Genuine WHS compliance means working down the hierarchy from the top, only reaching for PPE once the higher-order controls have been considered and, where reasonably practicable, applied.
What Is a High Risk Work Licence?
A High Risk Work Licence is the national licensing scheme, issued by each state or territory's WHS regulator under nationally consistent competency units, that authorises a worker to operate specific categories of high-risk plant and equipment — including cranes, hoists, forklifts, scaffolding, and dogging and rigging work.
Two of those licence classes have direct relevance to AIMS's own Lifting & Rigging range: dogging (directing crane operators and attaching/detaching loads using slings, shackles and other rigging gear) and rigging (erecting and dismantling the plant, structures and load-bearing gear a lift depends on) are exactly the work the slings, shackles, chain blocks and wire rope covered in that category are used for. Holding the right class of licence is a legal precondition for that work under WHS laws, independent of whether the equipment itself meets its own Australian Standard.
What Are Hitch Types — Vertical, Choke & Basket?
Hitch type describes how a sling is connected between the crane hook and the load, and it directly changes the sling's effective Working Load Limit: a vertical (straight) hitch uses the sling's full rated WLL, a choker hitch — where the sling is looped back through its own eye to cinch the load — derates to roughly 75% of the vertical WLL, and a basket hitch — cradling the load in a U rather than pulling straight — can rate up to 200% of the single-leg vertical WLL, though that maximum only applies at a true 90° basket angle and drops as the Sling Angle Deration increases. Getting the hitch type and the WLL tag talking to each other correctly is one of the most common rigging errors worth double-checking before a lift.
What Is Lifting Hook Geometry — Eye, Clevis, Swivel, Self-Locking & Foundry?
Lifting hook geometry refers to how a hook connects at its top end and behaves under load: an eye hook has a fixed round eye for a shackle or sling connection; a clevis hook connects through a pin, giving a more compact fixed attachment; a swivel hook rotates freely on a bearing, letting a suspended load turn without twisting the sling; a self-locking hook adds a mechanism that closes the throat under load rather than relying on a simple spring latch alone; and a foundry hook has a deep, wide throat shaped to safely carry a ladle or similarly bulky load. Matching the geometry to the job matters as much as matching the WLL — a fixed eye hook on a load that needs to rotate freely will twist the sling instead.
What Is a Lifting Hook's Throat and Saddle?
The throat of a lifting hook is the open gap between the hook's tip and its body, through which the sling or chain is loaded; the saddle is the curved inner surface at the base of the hook where the load actually bears. Throat opening is a standard inspection point — a hook that's been overloaded or side-loaded will show a measurably wider throat gap than its as-manufactured spec, which is one of the rejection criteria a rigger checks for alongside cracking and wear.
What Is Hot Dip Galvanizing (HDG)?
Hot dip galvanizing is a coating process where steel parts are immersed in a bath of molten zinc at around 450°C, forming a series of zinc-iron alloy layers with a pure zinc outer layer — a metallurgical bond rather than the electrodeposited layer Electroplating produces. AIMS's own guide gives the practical numbers: coating thickness of 45–100 microns (typically 50–85 µm, several times thicker than standard Zinc Plating), a salt-spray-test life of 1,000-plus hours versus 96–120 hours for plain zinc plate, and real-world outdoor service life of 25–50-plus years — which is why HDG, not standard zinc plate, is what's specified for outdoor and structural steel in Australian conditions.
That extra coating thickness genuinely changes thread fit: HDG nuts are tapped oversize to compensate, and AS 1684 specifically requires HDG (minimum 42 µm) or stainless for H3/H4 treated pine, with A4-316 stainless only for H5/H6.
If the HDG coating gets damaged or worn on site — welds, cuts, drilled holes — it needs a zinc-rich cold-galvanising spray to touch up, not a rust converter: a rust converter reacts with iron oxide, not zinc coating, so it does nothing useful on damaged galvanising. See AIMS's Rust Converter Guide for the full explanation.
Read AIMS's full Zinc Plated vs Galvanised vs Stainless: Bolt Coatings Guide →
What Is HPPE? (High-Performance Polyethylene)
HPPE — high-performance (or ultra-high-molecular-weight) polyethylene — is a synthetic fibre valued for a very high strength-to-weight ratio that resists blade cuts well at a lighter weight than older fibres like Kevlar®.
It's become one of the most common cut-resistant glove liner materials on the market precisely because it delivers a high EN 388 cut rating (commonly 4542C to 4543D, and up to F with technologies like Dyneema Diamond) while staying lighter and more comfortable for full-shift wear than steel-fibre or heavier Kevlar® gloves. HPPE is often blended with glass fibre for extra cut resistance or with Lycra for stretch and fit.
Read AIMS's full Work Glove Types guide →
Shop AIMS's range of hand protection →
What Is HRC Fuse (NH00–NH3, BS88)?
An HRC (High Rupturing Capacity) fuse is a cartridge-type fuse designed to safely interrupt very high fault currents without the fuse body itself rupturing or arcing — standard protection for switchboards and heavy industrial circuits rather than the household circuit-breaker-and-RCD setup. NH-sized fuses (NH00 through NH3, and beyond) follow a German-origin DIN sizing system by physical body size and current rating, while BS88 is the equivalent British/AU cartridge fuse standard; both are common in AU industrial and commercial switchboards, and the physical size — not just the amperage marking — needs to match the fuse holder.
What Is HSS (High Speed Steel)?
HSS (High Speed Steel) is a tungsten-molybdenum-vanadium-chromium tool steel alloy, and the standard material for general-purpose cutting tools — drill bits, taps, reamers and end mills — where it retains its cutting edge at the temperatures generated drilling wood, plastics and mild steel. It sits at the affordable, tough end of the cutting-tool material hierarchy: roughly 850 HV hardness, low cost, fully regrindable when it dulls, and tough enough to survive an interrupted cut or a less-than-perfectly-rigid setup that would chip a brittle Solid Carbide (VHM) tool outright. Where a job outgrows plain HSS — stainless steel is the classic case, since it work-hardens and will blunt a plain HSS edge rapidly — HSS-Co (Cobalt High-Speed Steel) is the next step up, not a jump straight to carbide.
Read AIMS's full Choosing the Right Drill Bit guide → and Cutting Tool Materials Guide → for the full material hierarchy
What Is HSS-Co (Cobalt High-Speed Steel)?
HSS-Co is standard HSS alloyed with cobalt, which raises both hardness and heat resistance at the cutting edge — AIMS stocks two grades, M35 (5% cobalt, roughly 880–920 HV, the minimum genuinely needed for stainless steel, alloy steel and intermittent cuts) and M42 (8% cobalt, for genuinely difficult-to-machine materials and taps used in stainless or harder alloys). The extra cobalt content is specifically why HSS-Co survives stainless steel's work-hardening tendency where a plain HSS bit fails fast — stainless steel demands at minimum the 5% cobalt content M35 provides, not just "a better HSS bit" in a general sense.
Read AIMS's full Cobalt Drill Bit Guide → for M35 vs M42 selection, and the Cutting Tool Materials Guide → for where it sits in the full material hierarchy
What Is HV? (Hardness Vickers / High Voltage)
HV is one of the more genuinely ambiguous acronyms in industrial use, and which meaning applies depends entirely on context. In materials and measurement work, HV is the standard abbreviation for Vickers Hardness (see below) — a diamond-pyramid indentation hardness scale. In electrical work, HV means High Voltage — see the Electrical category for voltage-class terminology in that sense. AIMS's own measurement, metrology and hardness-testing content always uses HV for Vickers hardness; if HV turns up on an electrical drawing or switchgear spec, it almost certainly means high voltage instead — the surrounding context (a hardness certificate versus a wiring diagram) resolves it immediately in practice.
What Is HVAC? (Heating, Ventilation & Air Conditioning)
HVAC stands for Heating, Ventilation and Air Conditioning — the umbrella term for every system and piece of equipment that controls a building or workshop's internal air temperature, humidity and air quality, from a single portable Radiant Heater (Industrial) through to a full mechanical ventilation system designed to AS 1668.2.
On an Australian industrial or workshop floor, "HVAC" rarely means ducted comfort air conditioning the way it might in an office — it's usually a much more targeted mix of equipment, chosen for the specific problem at hand: a Forced-Air Convection Heater or Indirect-Fired Diesel Heater for winter heat recovery in a large open bay, and an HVLS Fan, Mancooler or Evaporative Cooler (Industrial) for summer heat stress, each sized to the space using CFM.
Read AIMS's full Industrial Heating Guide and Industrial Cooling Guide →
Shop AIMS's range of HVAC & refrigeration equipment →
What Is an HVLP Spray Gun? (High Volume, Low Pressure)
An HVLP spray gun atomises paint or coating using a high volume of air at low pressure at the cap — around 10 psi (0.7 bar) — rather than the high pressure a conventional spray gun uses. That lower cap pressure means the paint arrives at the surface more gently and with less bounce-back, giving 65–80% transfer efficiency onto the panel compared with 25–35% for a conventional high-pressure gun: more paint on the job, less wasted as overspray, and less airborne solvent to manage.
The trade-off is air supply: HVLP is a genuinely continuous-duty load, demanding 10–30 CFM sustained rather than the short intermittent bursts most air tools need — which in practice means a 15–35 CFM-capable compressor, typically a 60-gallon-plus shop unit, not the small direct-drive compressor that runs an impact wrench fine. Nozzle size has to match the coating: 0.8 mm for touch-up work, 1.0–1.3 mm for basecoat and clearcoat, up through 1.7–2.2 mm for heavy primer — get it wrong and the result is orange peel or runs, not a gun fault. See Duty Cycle (Air Compressor) and Rotary Screw Compressor for why a continuous-duty spray setup often needs a different class of compressor than the rest of the workshop.
Read AIMS's full Air Tools Guide → for nozzle sizing by coating type
Shop AIMS's range of air guns — blow, spray & cleaning →
What Is an HVLS Fan? (High Volume, Low Speed)
An HVLS fan — High Volume, Low Speed — is a large-diameter ceiling fan, typically 2.4 m to 7.3 m across the blade span and turning much more slowly than a conventional ceiling or pedestal fan, that moves a huge volume of air efficiently by relying on blade surface area rather than speed to do the work.
One fan can condition a genuinely large footprint — AIMS's own sizing guidance puts a 6 m-diameter fan in the order of 100–280 m² depending on ceiling height, with larger warehouses needing a multi-fan grid rather than one oversized unit. That's a fundamentally different job to a Mancooler, which concentrates airflow at one specific work area rather than circulating and destratifying air across a whole floor. Power supply is a genuine spec constraint when choosing a model: AIMS's own 4 m HVLS fan runs on a standard Single-Phase Fan/Heater Supply (240V), while the 5.5 m, 6.1 m and 7.3 m models step up to a Three-Phase Fan/Heater Supply (415V) — worth checking before specifying a fan for a workshop without three-phase already installed.
Read AIMS's full Industrial Ceiling Fan Guide and Industrial Cooling Guide →
Shop AIMS's range of HVAC & refrigeration equipment →
What Is a Hybrid Bearing (Ceramic Rolling Elements)?
A hybrid bearing keeps conventional steel inner and outer races but replaces the Rolling Elements with ceramic ones — silicon nitride, typically — which are electrically insulating as well as harder and lighter than steel. That electrical insulation makes a hybrid bearing one of the most effective long-term fixes for Electrical Fluting in VFD-driven motor applications, since stray current simply can't arc through the ceramic balls or rollers the way it does through steel ones.
The reduced weight and lower friction of the ceramic rolling elements also suit high-speed spindle applications, independent of the electrical benefit.
Read AIMS's full Rolling Bearings: Types, Selection, Fitting & Failure Guide →
What Is Hydraulics?
Hydraulics is the general field of fluid-power systems that transmit force through pressurised liquid — almost always hydraulic oil — rather than through mechanical linkages, gears or compressed air.
The three components that come up constantly across a hydraulic system are the fluid itself (see Hydraulic Oil for its own selection criteria), the connections joining pump, cylinder and hose together (see BSP, NPT and the BSPT / BSPP distinction for how those connections actually seal), and the flexible lines carrying pressurised oil between fixed components (see Industrial Hose for hydraulic hose construction and pressure ratings specifically).
Shop AIMS's range of hydraulic fittings and high-pressure fittings (ISO 1179 & ISO 6149) →
What Is Hydrogen Embrittlement?
Hydrogen embrittlement is a form of delayed brittle failure in high-strength steel caused by atomic hydrogen absorbed into the metal — commonly during electroplating or acid pickling — diffusing to areas of high internal stress and reducing the metal's ability to deform before cracking, sometimes causing a fastener to fail under normal service load well after installation, with no warning.
Higher-strength fasteners (Grade 10.9 and 12.9, and their imperial equivalents) are significantly more susceptible than lower grades, because their higher hardness leaves less ductility to absorb the embrittling effect before cracking starts. The standard mitigation is Baking shortly after plating, verified against ASTM F519 test requirements. *(Independent standards source — ASTM F519 and published fastener-engineering literature — no dedicated AIMS article for this metallurgical failure mode.)*
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What Is an Idler Pulley?
An idler pulley is a non-driving pulley added to a belt drive to maintain tension or redirect the belt's path, rather than to transmit power to or from a shaft itself.
There are two distinct types: a tensioner idler, which is spring-loaded or manually positioned specifically to keep the belt at correct tension, and a routing idler, fixed in position purely to redirect the belt or increase its wrap angle around another pulley. Getting the type wrong matters — a routing idler used where a tensioner idler is needed won't compensate for belt stretch over time, leading to the slip and glazing symptoms covered under Belt Tensioner.
Read AIMS's full Pulley Types Guide →
Shop AIMS's range of idler pulleys →
What Is an IE Efficiency Class (IE2/IE3/IE4)?
IE efficiency class, set out in IEC 60034-30-1, rates an electric motor's energy efficiency: IE2 is "High Efficiency" and is largely no longer sold as a standard catalogue item for general industrial use in Australia; IE3 is "Premium Efficiency" and is the current MEPS minimum for most three-phase Induction Motors sold in Australia; and IE4 is "Super Premium Efficiency," available for higher-duty-cycle applications where the efficiency gain justifies the extra cost. See MEPS below for the regulatory scope this sits inside.
What Is the Impact Class for Safety Glasses? (F / B / A)
Impact class rates how much mechanical force a lens can withstand under AS/NZS 1337.1, from F (low impact, roughly 45 m/s, for basic particle hazards) through B (medium impact, roughly 120 m/s, for standard industrial grinding and cutting) up to A (high impact, roughly 190 m/s, for heavy-duty grinding and high-velocity debris).
Impact class is independent of Optical Class — a pair of glasses needs both ratings assessed separately, since a high impact-rated lens doesn't automatically carry premium optical clarity, and vice versa.
Read AIMS's full Safety Glasses Guide →
What Is Imperial (Measurement System)?
Imperial describes the system of measurement built on units such as inches, feet, pounds and pounds-force — historically used across the British Empire and still in everyday and trade use in the United States and, in specific pockets, Australia. Australia officially converted to metric in the 1970s, but imperial sizing persists heavily in legacy plant, imported American and British equipment, plumbing thread standards (BSP, NPT) and some fastener ranges — which is why AIMS stocks genuine imperial ranges alongside metric rather than treating imperial as obsolete stock. See Metric below, and OD / ID and Calliper above for how the two systems commonly show up side by side on a single measuring instrument or drawing.
What Is an Indexable Insert?
An indexable insert is a small piece of tungsten carbide (or another hard cutting material), shaped to a specific geometry — diamond, triangle, square, round and others — and mechanically clamped, rather than brazed or welded, into a steel Toolholder. The practical payoff is real: each insert carries multiple usable cutting edges, so when one edge dulls, the operator rotates ("indexes") the insert to a fresh edge or swaps it for a new one entirely, without needing to re-set or recalibrate the machine's tool offset the way a re-ground solid tool would demand. Inserts are designated by a position-by-position code under ISO 1832 Insert Code (see below), and are commonly finished with a PVD Coating to extend their working life well beyond an uncoated equivalent.
Read AIMS's full Indexable Insert Guide → for the complete ISO 1832 code breakdown and a worked decoding example
Shop AIMS's range of indexable inserts →
What Is an Indirect-Fired Diesel Heater?
An indirect-fired diesel heater burns diesel in a sealed combustion chamber and ducts the exhaust outside the building, so only clean, heated air is blown into the workspace — never combustion by-products. That's the defining difference from a direct-fired heater, which burns fuel in the open airstream and vents the exhaust straight into the room along with the warm air.
The trade-off is efficiency for safety: a direct-fired heater runs at close to 99% efficiency (no heat is lost up a flue), while an indirect-fired unit sits closer to 80% because usable heat leaves with the ducted exhaust. That trade-off is non-negotiable in a sealed or enclosed workshop — direct-fired heating indoors has caused documented carbon monoxide fatalities, and WHS Regulation 49's atmospheric contaminant limits make indirect-fired the only safe choice for automotive bays, enclosed fabrication shops and anywhere else workers are present without cross-ventilation. Direct-fired units stay confined to outdoor or genuinely open-bay use, like construction sites. Like other combustion heaters, the fan and ignition electronics typically run off a standard Single-Phase Fan/Heater Supply, with larger commercial units stepping up to Three-Phase Fan/Heater Supply.
Read AIMS's full Industrial Heating Guide →
What Is an Induction Bearing Heater?
An induction bearing heater is a workshop tool that heats a bearing electromagnetically so it expands enough to slide onto a shaft without being pressed or hammered into place — the preferred fitting method for medium and large Interference Fit bearings, since it avoids the raceway damage (Brinelling) that force-fitting risks. AIMS's own guide is specific about the safe window: target 80–100°C, never exceeding 120°C, since going hotter permanently alters the bearing steel's heat treatment and changes its clearance and hardness. In practice, a bearing typically reaches temperature in 2–5 minutes, giving roughly 30–60 seconds to get it onto the shaft before it cools enough to grip prematurely.
AIMS doesn't currently stock induction bearing heaters as a dedicated product line — included here on relevance to the trade, per the coverage principle agreed for this glossary, not because it's part of the current range.
Read AIMS's full Bearing Maintenance: Inspection, Lubrication & Replacement Guide →
What Is an Induction Motor?
An induction motor is an AC electric motor in which the rotor is driven by electromagnetic induction from the stator's rotating magnetic field, rather than by physical electrical contact — meaning no brushes and no commutator to wear out. This brushless design is why the induction motor is the standard workhorse motor across Australian industrial, pump, fan and conveyor applications: it's simple, robust and largely maintenance-free by comparison with brushed motor types. Virtually all industrial electric motors sold in Australia for pump, fan, conveyor, compressor and general machinery applications are induction motors — DC motors exist for specialist variable-speed applications without a VFD (Variable Frequency Drive), but they're a minority in general industrial use.
An induction motor's Motor Poles count sets its base speed, its Motor Frame Size (IEC/AS/NZS 1359) and mounting determine physical fit, and its Motor Insulation Class and IE Efficiency Class rating are worth checking alongside those before a like-for-like replacement — matching the designation number alone isn't enough if the application runs hot or continuously.
Read AIMS's full Electric Motor Guide → or Motor Starting Methods Guide → (DOL vs star-delta vs soft starter vs VFD)
Shop AIMS's range of electric motors →
What Is Industrial Hose?
Industrial hose is flexible tubing built to carry a specific fluid or gas at a specific pressure and temperature — air, water or hydraulic oil each demand genuinely different construction, and treating them as interchangeable is a real and dangerous mistake, not just a technicality.
Air hose runs 12–30 bar depending on construction, with a minimum 4:1 safety factor over working pressure built in, in PVC (cheapest, but stiffens below 10°C and resists kinking poorly), rubber (three times heavier than polyurethane, excellent kink and abuse resistance), polyurethane (a third of rubber's weight, but kinks more readily), or a hybrid balancing both. Hydraulic hose is built from an inner tube compatible with the specific fluid, one or more braided or spiral-wound steel-wire reinforcement layers, and an outer cover, rated under the SAE J517 100R system from 100R1 (single wire braid, 85–215 bar, general medium-pressure and return lines) up to 100R9 (four-spiral wire, 350–480 bar, mining and earthmoving duty) — with a hard maximum service life of six years from the manufacture date regardless of visible condition, since abrasion alone causes more than 57% of early hydraulic hose failures. Water hose ranges from a modest 3–10 bar for general low-pressure use up to 100–3,000 bar for high-pressure jetting — an enormous range that makes checking the actual rated pressure non-negotiable before connecting a hose to a jetting unit. Never substitute a garden hose for compressed air: a garden hose carries only a 2:1 safety factor against air hose's 4:1, and a burst under air pressure causes an explosive, whipping failure rather than a simple leak; equally, hydraulic hose must never be used for compressed air, since it lacks compressed-gas safety certification even where the pressure rating looks adequate on paper. See BSP, NPT and BSPT / BSPP for how the fittings on the end of a hose actually seal, since a correctly-rated hose with the wrong fitting is just as much a failure point as the wrong hose.
Read AIMS's full Industrial Hose Guide and Hydraulic Fittings Guide →
Shop AIMS's range of hose, ducting & fittings →
What Is an Inertia Reel? (Self-Retracting Lanyard)
An inertia reel — also called a self-retracting lanyard (SRL) — is a fall-arrest device with a cable or webbing line on a spring-loaded reel that locks almost instantly under sudden load, the way a car seatbelt does, arresting a fall within centimetres rather than allowing metres of free fall.
That short arrest distance is exactly why an SRL is specified over a fixed-length shock-absorbing lanyard in low-clearance situations — roof work below 5–6 m, elevated work platforms, confined spaces — where a standard shock-absorbing lanyard's total fall distance of 3–4 m (including the energy absorber's own stretch) would mean hitting the ground or a lower level before the fall is actually arrested. One mistake worth knowing about specifically: attaching a lanyard or SRL to the same ladder or structure the worker is standing on defeats the whole system, since if the worker falls, the anchor falls with them — the anchor point must always be a separate, independently rated structure.
Read AIMS's full Safety Harness Guide →
Shop AIMS's range of height safety equipment →
What Is INOX Marking?
An INOX marking on a cutting or grinding disc certifies the disc is free of iron, sulphur and chlorine contaminants that would otherwise embed in a stainless steel surface and cause corrosion — visible as unsightly rust spots weeks or months after the work was done. Always confirm a disc carries the INOX marking before using it on stainless; a standard mild-steel-rated disc, even if physically identical, is not a safe substitute.
What Is an Interference Fit (Bearing)?
An interference fit is a controlled press-fit between a bearing ring and its mating shaft or housing — sized so the ring is gripped tightly enough to prevent it creeping under load, but not so tight that fitting it damages the bearing. AIMS's own guide states the governing principle plainly: fitting force must be applied only to the ring actually being fitted — the inner ring when mounting onto a shaft, the outer ring when pressing into a housing — and never transmitted through the rolling elements, which is what causes Brinelling.
See Clearance Fit elsewhere in this glossary for the opposite mounting condition — a fit loose enough to allow relative movement rather than gripping the mating part.
Read AIMS's full Bearing Maintenance: Inspection, Lubrication & Replacement Guide →
What Is Inventory?
Inventory is the stock of goods a business holds — raw materials, work-in-progress and finished goods — ready to be used in production or sold to customers.
For a trade or industrial business, inventory management is a constant balancing act: too much stock ties up cash and warehouse space, too little risks stockouts and downtime. It's closely tied to MRO (spares and consumables kept on hand specifically to support maintenance and repair work), SKU (the individual stock-keeping unit each inventory line is tracked by) and UOM (the unit each quantity is counted and ordered in).
What Is IP Rating (Ingress Protection)?
An IP Rating (Ingress Protection rating) is a two-digit code, defined in IEC 60529 (adopted in Australia as AS/NZS 60529), that specifies how well an electrical enclosure, motor or fitting resists solid objects and dust (first digit, 0–6) and water (second digit, 0–8, plus a separate 9K rating). The first digit runs from no protection (0) up through protection against fingers (2), tools and thick wire (3), thin wire and small tools (4), dust-protected (5) to fully dust-tight (6); the second runs from no protection (0) through dripping water (1–2), spraying (3), splashing (4), low-pressure jets (5), powerful jets (6), temporary immersion to 1 m (7) and continuous immersion (8), with 9K as a separate rating for high-pressure, high-temperature washdown (80°C water at 80–100 bar) common in food and dairy processing.
In everyday AU industrial use: IP55 (dust-protected, water jets) is the standard general-purpose outdoor motor rating; IP65 (dust-tight, water jets) suits outdoor luminaires and sensors; IP66 (dust-tight, powerful jets) is the washdown and food-processing standard; IP67 and IP68 step up to temporary and continuous immersion for submersible equipment; and IP69K is reserved for hot high-pressure CIP washdown areas. The higher each digit, the greater the protection — but a rating is only ever as good as its lowest-rated component in an assembled system, so an IP66 enclosure with an unrated Cable Gland fitted to it isn't actually an IP66 installation. See Motor Enclosure Type (TEFC/ODP/TEAO/TENV) for how this relates to — but isn't the same spec as — a motor's cooling and enclosure design.
Read AIMS's full IP Rating Guide → or Electric Motor IP Ratings → for the complete digit-by-digit chart
What Is ISO? (International Organization for Standardization)
ISO is the independent, non-governmental international body that develops and publishes voluntary consensus standards, headquartered in Geneva and made up of one national standards body per member country — Standards Australia is Australia's representative, and ANSI represents the United States.
ISO itself is the standards-setting organisation, not any single standard — it's published well over 20,000 of them, covering everything from screw thread tolerances to environmental management. ISO 9001 — Quality Management, covered as its own entry in this glossary, is one specific ISO standard among that much larger catalogue, and shouldn't be confused with the body that publishes it.
What Is ISO 1101? (GD&T Tolerancing)
ISO 1101 is the international standard for geometric tolerancing — it defines the symbols, rules and datum system used to specify how a feature's form, orientation, location and runout are permitted to vary, going beyond a simple plus-or-minus dimension. It's one of three standards Australian engineers commonly encounter on the same drawing type — ISO 1101 (international, European-aligned), ASME Y14.5 (US-origin, common in aerospace/automotive/defence) and AS/NZS 1100.201 (the local Australian/NZ standard, which adopts ISO conventions but permits either style) — and a drawing's title block, not assumption, is what actually specifies which one applies; mixing conventions without checking is a genuine, avoidable source of inspection disputes. See GD&T above for the complete 14-symbol set ISO 1101 governs.
Read AIMS's full GD&T Symbol Cheat Sheet → for how ISO 1101 and ASME Y14.5 compare symbol-by-symbol
What Is ISO 13997? (Cut Resistance Testing)
ISO 13997 is the test method that produces the letter-grade component (A–F) of a glove's EN 388 Rating Structure — a straight-blade cut test that's considered more reliable than the older Coupe (rotating blade) test alone, especially against sharp or textured cutting edges that can blunt a rotating blade unrealistically fast.
A glove's ISO 13997 letter and its Coupe-test digit can tell slightly different stories on the same product, which is exactly why the full rating carries both rather than either alone.
Read AIMS's full Work Glove Types guide →
What Is ISO 1832 Insert Code?
ISO 1832 is the international standard that defines the position-by-position designation code stamped on every Indexable Insert — a short alphanumeric string that fully specifies the insert's physical geometry without needing a drawing. Reading left to right: the first letter gives the insert's shape and included angle (e.g. C = 80° diamond); the second gives its clearance angle or rake type (e.g. N = 0° negative rake); the third gives its tolerance class; the fourth its hole and chipbreaker type; positions five and six its cutting-edge length in millimetres; seven and eight its thickness; and nine and ten its corner radius, with any brand-specific suffix identifying a manufacturer's own chipbreaker or grade designation on top of the ISO code. As a worked example, an insert marked CNMG 120408 decodes as an 80° diamond, negative-rake insert with a 12.7mm cutting edge, 4.76mm thickness and a 0.8mm corner radius — a toolholder buyer or machinist can read the insert's complete geometry straight off that code without ever seeing the part in hand.
Read AIMS's full Indexable Insert Guide → for the complete 10-position code table and worked decoding examples
What Is ISO 286? (Holes & Shafts Tolerance System)
ISO 286 is the international standard that defines tolerance classes for holes and shafts — a letter-and-number code such as H7 or h6 that specifies the permitted upper and lower size deviation from nominal, so a hole and shaft made to matching classes fit together predictably (clearance, transition or interference) without either party needing to state the actual tolerance figures on the drawing. It directly governs inspection gauge selection: the widely used "4-to-1 rule" (from ANSI/NCSL Z540-1) requires an inspection gauge to be at least four times more accurate than the workpiece's ISO 286 tolerance band — for a 25H7 hole (tolerance +0/+0.021mm), that requires a GO/NO-GO pin gauge pair accurate to better than ±5.25 microns, which in practice puts the gauge at Gauge Maker Class Z or finer. See GO / NO-GO Gauge above for how that pass/fail check is actually carried out on the shop floor.
Read AIMS's full Pin & Plug Gauge Guide → for ISO 286 tolerance classes and the gauge-selection worked example
What Is ISO 3506 (Stainless Steel Fastener Mechanical Properties)?
ISO 3506 is the international standard defining mechanical property classes for stainless steel (corrosion-resistant) fasteners, marked with a material designation plus a strength-class suffix — A2-70 (304 stainless, 700 MPa minimum tensile) and A4-80 (316 stainless, 800 MPa minimum tensile) are the two most common combinations in Australian industrial supply.
The material designation and the strength suffix answer two different questions: A2 vs A4 is about corrosion resistance (A4's added 2–3% molybdenum lifts its Pitting Resistance Equivalent Number from roughly 18–20 up to 23–28.5, meaningfully better against chloride-driven pitting and crevice corrosion), while -70 vs -80 is purely about strength. AIMS's guide is direct on when the upgrade to A4 is worth it: marine, coastal, pool and food-processing environments with chloride exposure justify A4; general engineering and non-chloride environments are well served by A2.
Read AIMS's full Stainless Fastener Grades Guide → for A2 vs A4 and -70 vs -80 in full
Shop AIMS's range of fasteners →
What Is ISO 4014 (Hex Head Bolts, Metric)?
ISO 4014 is the international metric standard for partial-thread hexagon head bolts — an unthreaded shank runs beneath the head with thread only at the working end — designed so the shear plane in a bolted joint falls across the stronger, unthreaded shank rather than across the weaker thread roots.
Australia adopts this standard as AS 1110, and it stands in direct contrast to DIN 933 — Hex Bolts (Full Thread) below, which threads the full length instead: partial-thread bolts to ISO 4014/AS 1110 are the correct choice for shear-loaded structural and machinery joints, while full-thread bolts suit tapped-hole applications needing maximum thread engagement rather than shear strength.
Read AIMS's full Hex Bolt Guide → for partial vs full thread selection and AF spanner sizing
Shop AIMS's range of hex bolts →
What Is ISO 4762 (Socket Head Cap Screws, Metric)?
ISO 4762 is the international metric standard for socket head cap screws, dimensionally identical to the German DIN 912 — Socket Head Cap Screws above — the two standard numbers describe the same fastener, and a screw certified to one meets the dimensional and thread requirements of the other.
In practice, Australian and international suppliers use "DIN 912" and "ISO 4762" somewhat interchangeably when describing the same physical product, though ISO 4762 is technically the internationally harmonised reference and DIN 912 the original German national standard it superseded in formal terms.
Read AIMS's full Socket Head Cap Screw Guide → for sizing, grades and torque
Shop AIMS's range of socket head cap screws →
What Is ISO 513 K-Grade Carbide Classification?
ISO 513 is the international standard that classifies tungsten carbide cutting-tool grades by the workpiece material family they're designed to cut, using a letter-and-number code — and it's worth being precise that this is a distinct kind of "grade" from a fastener grade, steel grade or abrasive grit grade elsewhere in AIMS's range, despite sharing the word. The six letter groups are P (steel and long-chipping materials), M (stainless steel and other work-hardening materials), K (cast iron and non-ferrous materials), N (aluminium and other non-ferrous alloys), S (superalloys — nickel-base, cobalt-base, titanium alloys) and H (hardened materials above roughly 45 HRC). A numeric suffix then places the specific grade on the hardness-versus-toughness spectrum within its letter group: low numbers (01, 10, 15) mark the hardest, least tough grades, reserved for finishing and precision work; mid numbers (20, 25) mark a general-purpose balance; and high numbers (30, 40) mark the toughest, softer grades, suited to interrupted cuts and roughing. A grade marked K20, for instance, decodes as a cast-iron/non-ferrous grade at a general-purpose hardness/toughness balance.
Read AIMS's full Cutting Tool Materials Guide → for the full ISO 513 letter-group and numeric-suffix system
What Is ISO 5211? (Actuator Mounting Flange Standard)
ISO 5211 is the international standard for the mechanical interface between a quarter-turn actuator and the valve it drives — a four-bolt flange pattern paired with a square drive socket on the valve stem, standardised by size code so actuator and valve from different manufacturers can bolt together directly. The common F-number sizes (F05, F07, F10 and others) each specify a fixed pitch circle diameter, bolt thread and drive-square dimension, with F07 the most common flange size on industrial ball valves up to DN 80 in Australian practice.
The standard applies regardless of whether the actuator is pneumatic, electric or manual — it's purely a mounting interface, not a statement about how the actuator is powered or fails (see Actuator Fail-Safe Mode for that). The practical benefit is eliminating guesswork at spec and replacement time: confirm both the actuator and the valve carry the same ISO 5211 F-number and they mount directly, with no custom bracket or adapter needed — mismatch the F-number and you're either machining an adapter plate or ordering the wrong part twice.
Read AIMS's full Valve Actuator Guide → for the full F03–F10 flange dimension table
Shop AIMS's range of pneumatic & linear actuators →
What Is ISO 5211? (Valve Actuator Mounting)
ISO 5211 is the international standard defining the mounting interface between a valve and its actuator — the bolt pattern, flange size and stem coupling dimensions that let a pneumatic or electric actuator from one manufacturer bolt straight onto a valve from a different manufacturer.
This standardisation is what makes vendor-independent actuator replacement possible: a valve built to an ISO 5211 mounting pad can be automated, or have its actuator swapped or upgraded, without needing a custom bracket or a matched valve-actuator pair from a single supplier. See Ball Valve for where this matters most in practice — AIMS's own 3-piece ball valve range includes an ISO 5211 actuator mounting pad specifically for this reason.
Read AIMS's full Ball Valve Guide →
What Is ISO 6789 (Torque Tools/Wrenches)?
ISO 6789 is the international standard governing torque wrench design, classification, accuracy and calibration, split into two parts: ISO 6789-1 (design conformance testing) and ISO 6789-2 (calibration and measurement uncertainty).
The standard classifies torque wrenches into Type I (setting) tools — click, split-beam click and adjustable-click wrenches that signal when the set torque is reached — and Type II (indicating) tools — beam, dial and digital/electronic wrenches that display the applied torque continuously for the operator to read. Both types must meet ±4% accuracy across their rated range under the standard (premium manufacturers commonly build tighter, to around ±2%), and ISO 6789 recommends recalibration no less often than every 12 months or 5,000 operations, whichever comes first — shorter intervals are common in safety-critical industries.
Read AIMS's full Torque Wrench Calibration Guide → and Torque Wrench Guide → for Type I/II classification and calibration intervals
Shop AIMS's range of torque wrenches & screwdrivers →
What Is ISO 898-1 (Mechanical Properties of Fasteners)?
ISO 898-1 is the international standard defining the mechanical property classes for steel fasteners under external (tensile) loading — it's the standard that actually defines the 4.6/5.8/8.8/10.9/12.9 property class system explained under Property Class above, including the tensile and yield strength each class number represents.
Australia adopts this standard directly as AS/NZS 4291.1, so a Property Class 8.8 bolt tested and marked to either standard means exactly the same thing — 800 MPa minimum tensile strength, 640 MPa minimum yield. ISO 898-2 is the companion standard covering nuts, referenced under AIMS's own types-of-nuts guide for matching a nut's proof-load rating to its paired bolt.
Read AIMS's full Bolt Grade Chart → for the ISO 898-1 property class table
What Is ISO 9001? (Quality Management)
ISO 9001 is the international standard specifying the requirements for a quality management system (QMS) — the world's most widely adopted ISO standard, setting out criteria built around customer focus, process management, risk-based thinking and continual improvement rather than dictating a specific product outcome.
It's worth keeping distinct from ISO itself, the standards-setting body — ISO 9001 is one specific, purchasable standard document among the many thousands ISO publishes, not the organisation. Certification to ISO 9001 is carried out by independent third-party certification bodies, not by ISO directly, and a supplier's ISO 9001 certification is a common procurement requirement across Australian industrial and government supply chains as evidence of a consistently managed quality process, distinct from a product-level standard like AS 1428.1 which sets requirements for a physical outcome rather than a management system.
What Is ISO/BS Roller Chain Numbering?
ISO/BS is the other of the two competing roller chain sizing systems used across Australian industrial supply, alongside ANSI Roller Chain Numbering — and despite both encoding pitch directly in the part number, they are not interchangeable: a chain's roller diameter and plate width differ between the two systems even at a matching nominal pitch.
Under ISO/BS, the leading number gives pitch in sixteenths of an inch — 10B has a 10/16" (5/8", 15.875 mm) pitch — with the letter B denoting British Standard (metric pitch) and the final digit showing strand count. Ordering by pitch alone, without checking which numbering system a supplier or an old sprocket is using, is a genuine and common mis-order risk.
Read AIMS's full Roller Chain Guide →
Shop AIMS's range of chain & sprockets →
What Is Isopropyl Alcohol (IPA)?
Isopropyl alcohol, or IPA, is a fast-evaporating solvent used for cleaning, degreasing and surface preparation before painting, bonding or electronics work — its main advantage over a Degreaser or Penetrating Oil being that it evaporates cleanly with no oily residue left behind, which matters where any residue would interfere with paint or adhesive adhesion.
Shop AIMS's range of lubrication products →
What Is IWRC (Independent Wire Rope Core)?
IWRC (Independent Wire Rope Core) describes a wire rope built around a steel-wire core rather than a fibre one, giving significantly more crush resistance under the drum pressure and clamping loads typical of heavy lifting and crane applications. AIMS's 6×19 IWRC and 6×36 IWRC constructions are the standard choice wherever a fibre-core rope's core could be crushed over repeated reeling — see Wire Rope Construction below for how the strand-and-wire-count notation works.
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What Is a Jack? (Bottle Jack / Trolley Jack)
A jack is a hydraulic or mechanical lifting tool used to raise a vehicle or heavy load for access underneath — a bottle jack is compact and lifts vertically directly under the load, while a trolley jack (floor jack) rolls into position under a vehicle and lifts via a long pump handle, giving more reach and a lower starting profile than a bottle jack of the same capacity.
Rated capacity is the essential safety figure on any jack, and it must never be treated as a substitute for proper axle stands once the load is raised — a jack holds a load up, it isn't rated to hold it safely for someone to then work underneath.
Read AIMS's full Bottle Jack & Hydraulic Ram Guide →
What Is a Jib Crane?
A jib crane is a crane with a horizontal arm (the jib) that pivots around a vertical mast or wall-mounted pillar, running a hoist trolley along its length to give lifting coverage over a fixed working area without the footprint of an overhead gantry crane. AIMS's range spans wall-mounted (fixed to an existing structural wall or column), free-standing (its own floor-mounted mast) and articulating (a jointed arm giving reach around obstructions) configurations, each suited to different workshop layouts.
What Is a Jobber Drill?
A jobber drill is the standard-length twist drill bit series — sitting between the shorter stub-length series (for rigid, close-to-the-chuck work) and the longer extra-length series (for reaching deep into a workpiece) — and is the default general-purpose drill length stocked and reached for in most Australian workshops. Unless a job specifically calls for the extra rigidity of a stub-length bit or the reach of an extra-length one, "jobber length" is the safe, standard assumption behind a plain drill bit order.
Shop AIMS's range of jobber drill bits →
What Is a Joint Sealant?
A joint sealant is a flexible compound applied into a gap or joint to block water, air, dust or gas from passing through, while still allowing the joint to move — expand, contract or flex — without the seal cracking or losing adhesion.
That flexibility requirement is what separates a sealant from a rigid adhesive or filler: Caulk and Putty are both common trade names for specific types of joint sealant, and RTV (Room Temperature Vulcanising) silicone is one of the most common sealant chemistries used where genuine ongoing flexibility is required.
K
What Is the K-Factor (Nut Factor)?
The K-factor (nut factor) is a dimensionless number used in the standard bolt-tightening formula T = K × F × d (torque = K-factor × preload force × nominal diameter) to convert a desired clamp force into the torque value that should, in theory, achieve it.
K-factor isn't a fixed material property — it captures all the friction in the joint (under-head friction, thread friction, and a small contribution from thread geometry), so it changes with plating, lubrication and surface condition rather than with the bolt's grade or diameter. AIMS's own torque chart gives worked K-factor values — roughly 0.20 for dry steel, 0.25 for hot-dip galvanised, 0.15 for lightly oiled and 0.13 for copper anti-seize — showing why the same bolt in different conditions needs meaningfully different torque to reach identical Clamp Force.
Read AIMS's full Metric Bolt Torque Chart → for the complete K-factor table and worked torque examples
What Is Kevlar®?
Kevlar® is DuPont's registered trademark for its para-aramid fibre, prized for a very high strength-to-weight ratio and good cut and heat resistance. In glove applications it typically earns an EN 388 cut-resistance rating in the C–E range depending on the weight and construction of the material.
Compared with HPPE (High-Performance Polyethylene) Fibre, Kevlar® gloves tend to be bulkier and can feel warmer in hot conditions, which is part of why HPPE-blend gloves have become popular as a lighter-weight alternative for cut protection where heat resistance isn't also required. Kevlar® remains a common choice for welding and foundry glove applications, where its heat resistance is the deciding factor.
Read AIMS's full Work Glove Types guide →
Shop AIMS's range of hand protection →
What Is a King Pin (Semi-Trailer)?
A king pin is the vertical, hardened steel pin fixed to the underside of a semi-trailer's bogie plate that locks into a Fifth Wheel Coupling on the prime mover (or into a Converter Dolly or Turntable further back in a combination), forming the pivot that lets the trailer articulate as the combination turns. Its condition and wear are a standard heavy-vehicle inspection point, since a worn king pin or coupling jaw can allow dangerous play between the trailer and the towing unit.
What Is Kingpin Weight?
Kingpin weight (also called king pin load) is the portion of a semi-trailer's total loaded weight that's transferred through its King Pin onto the Prime Mover's drive axles via the Fifth Wheel Coupling, rather than carried by the trailer's own axle group. It's a key figure in load distribution and axle-mass compliance calculations, since shifting freight further forward or back in the trailer changes how much weight ends up on the prime mover versus the trailer's own wheels.
What Do Kip, kN, MPa, PSI, Pascal & Newton Mean? (Force & Stress Units)
These are the force and stress/pressure units that turn up side by side on imperial-origin drawings and Australian metric ones, and mixing them up is an easy, costly mistake. The newton (N) is the SI unit of force; the kilonewton (kN) is 1,000 newtons. The kip ("kilopound," imperial) equals 1,000 pounds-force — approximately 4.448 kN. The pascal (Pa) is the SI unit of pressure and stress, defined as one newton per square metre; the megapascal (MPa) — one million pascals, equivalently one newton per square millimetre — is the everyday unit for material strength ratings in AU engineering, and equals approximately 145.04 psi (pounds per square inch), the imperial pressure and stress unit still common on US-origin drawings, datasheets and specifications. Reading an American datasheet's strength rating in psi as though it were already in MPa understates the actual strength by a factor of roughly 145 — always confirm which unit a spec sheet is actually using before converting or comparing figures across metric and imperial documentation. See SI below for how these units all derive from the same base system. *(General engineering fundamentals — no dedicated AIMS article for this term.)*
What Is a Knotted Wire Brush?
A knotted wire brush has its wires twisted together into tufts, giving a stiffer, more aggressive brush suited to heavy stock removal, weld cleaning and rust removal on a tough surface, in contrast to the gentler action of a Crimped Wire Brush. See Wire Brush Fill Material below for how the wire material itself is chosen alongside this construction choice.
What Is a Knurled Shank? (Ribbed / Splined)
Knurled, ribbed and splined all describe a textured or shaped fastener shank designed to resist rotation once installed — knurling is a fine crosshatch or straight-line pattern pressed into the surface; ribs are longitudinal raised lines running the length of the shank; splines are deeper, more pronounced longitudinal grooves, closer to gear teeth in profile.
On a rivet nut body specifically, a ribbed or knurled shank gives meaningfully better anti-rotation performance than a plain smooth (round) body without needing the exact hexagonal hole geometry a full hex nutsert requires — a practical middle option for installation into a plain drilled round hole in materials too soft for a smooth body to grip reliably. On a thumb screw or knurled knob, the same knurled texture instead serves purely to improve fingertip grip for hand-tightening.
Read AIMS's full Rivet Nut Guide → for body-type comparison by material
L
What Is a Lathe?
A lathe is a machine tool that rotates a workpiece against a stationary (or slowly-fed) cutting tool, the fundamental operation behind turning, facing, boring, knurling and thread-cutting on round or cylindrical parts. Correct spindle speed is what actually determines tool life and surface finish on a lathe — not a fixed RPM number, but the surface speed the workpiece's edge moves past the cutting tool at a given diameter, which is why the same cutting speed calls for a different RPM setting on a small-diameter part than a large one. See RPM below for the actual formula AIMS's own guide uses to convert a target cutting speed into the correct spindle-speed dial setting for a given workpiece diameter.
Read AIMS's full Lathe RPM Formula Guide → for the metric and imperial spindle-speed formulas
Shop AIMS's range of machining tooling →
What Is Leaf Chain?
Leaf chain is built from pin-connected plate links with no rollers at all, distinguishing it from a standard Roller Chain Drive chain — it's designed for lifting and counterbalance applications (forklift mast chains in particular) rather than for driving a sprocket as part of a power transmission system.
Because it has no rollers to engage sprocket teeth, leaf chain isn't a drop-in substitute for roller chain in a drive application — it runs over a sheave or through a lifting mechanism instead, and is specified by plate count and pitch rather than the ANSI/ISO pitch-and-roller system covered under ANSI Roller Chain Numbering and ISO/BS Roller Chain Numbering.
Shop AIMS's range of chain & sprockets →
What Is a Leaf Spring?
A leaf spring is a suspension component made of flat strips ("leaves") of spring steel stacked and clamped together, curved in the unloaded state so they flatten and flex under load — common on trucks, trailers and heavy 4WDs, where they carry the load, help locate the axle, and damp motion all at once. The three main types are semi-elliptical (multi-leaf), parabolic and mono-leaf. AIMS doesn't stock leaf springs itself — its own Types of Springs Guide covers them for completeness and points customers to suspension specialists or vehicle-parts wholesalers for sourcing — but the term is included here given how directly it comes up in trade conversation about truck and trailer suspension.
Read AIMS's full Types of Springs Guide → for how leaf springs compare with compression, extension and Belleville springs
What Is Length of Engagement (Thread)?
Length of engagement is the axial length over which an external and internal thread are actually meshed together — a bolt threaded fully into a nut or tapped hole versus one only just started has vastly different engagement, and therefore vastly different strength, even though it's nominally "the same fastener."
The standard rule of thumb for a tapped hole in steel is a minimum engagement equal to the nominal thread diameter (an M12 thread needs at least 12 mm of engagement) to develop the full strength of the bolt before the internal thread itself would strip; softer tapped materials (aluminium, brass) generally need proportionally more engagement to reach the same strength. AIMS's own threaded-rod guide uses exactly this rule when explaining coupling-nut length requirements. *(General engineering fundamentals, cross-referenced against AIMS's threaded rod guide — no single dedicated AIMS article on thread engagement itself.)*
What Is a Levelling Foot?
A levelling foot (leveling foot) is an adjustable-height fitting, typically threaded into a Tube Threaded Insert at the base of a machine frame, workbench or equipment stand, letting the unit be levelled on an uneven floor without shimming.
A tube insert is very often installed specifically to give a hollow-section frame leg somewhere to thread a levelling foot into, since the tube wall itself is almost always too thin to hold a useful thread directly on its own. *(General engineering/hardware terminology — no dedicated AIMS article for this term specifically.)*
What Is a Lever Block (Lever Hoist)?
A lever block (lever hoist) is a hand-operated lifting and tensioning device that uses a ratcheting lever, rather than an endless hand chain, to drive the same gear-and-load-brake mechanism found in a Chain Block. The lever action gives finer control over short, precise movements — tensioning a load, aligning machinery, or lifting in a confined space where there's no room to swing a hand chain — which is why lever blocks are the standard tool for rigging and positioning work rather than straight vertical lifting.
Read AIMS's full Lever Block Guide → for capacity, lift-height and lever-effort selection
Shop AIMS's range of chain blocks and lever hoists →
What Is a Linch Pin?
A linch pin is a fastener that passes through a drilled hole in the end of a shaft or axle — outside a wheel, hitch pin or implement — to stop the component sliding off, secured by a spring-loaded keeper or a bent retaining clip rather than by threads.
Linch pins are used specifically at shaft ends for retaining wheels and implements on agricultural and trailer equipment, and are functionally related to, but a heavier-duty item than, a general-purpose R-clip (hairpin pin) — both are tool-free, reusable retention pins, but a linch pin is sized and rated for genuine axle-end retention rather than light general-purpose use. *(General fastening-industry terminology, cross-referenced against AIMS's own split pin guide, which covers R-clips and linch pins as related items.)*
Shop AIMS's range of cotter pins & split pins →
What Is a Linisher?
A linisher is the Australian and New Zealand trade name for a belt sander/grinder machine — a continuous abrasive belt run over rollers or across a flat platen, used for stock removal, deburring, shaping and finishing metal or timber. Americans typically call the same machine a "belt grinder" — genuinely the same tool under a different regional name, much like G-Clamp / C-Clamp.
Because "linisher" is distinctly Australian and New Zealand vocabulary with comparatively little competing online content elsewhere, it's a high-value term for an AU/NZ-focused glossary specifically, not just a regional synonym worth a passing mention.
Read AIMS's full Belt Sander & Linisher Guide →
Shop AIMS's range of Linishall belt grinders & linishers →
What Is a Link Belt? (Segmented / Jointed Belt)
A link belt is built from individual links joined by a mechanical connector or lace, rather than as a single seamless loop like an Endless Belt — allowing the belt's length to be adjusted on site, or a single damaged link to be replaced without removing the pulleys from the drive.
This construction has been mostly superseded by endless belting in general industrial use, but it persists in some agricultural machinery and legacy drive applications where the ability to adjust length or repair in the field, without a full pulley strip-down, still outweighs the smoother running and stronger join of an endless belt.
Shop AIMS's range of Polyflex belts →
What Is Lithium Grease / Lithium Complex Grease?
Lithium soap grease is the standard multi-purpose industrial grease, rated to around 120°C, and lithium complex is a higher-performance version of the same soap chemistry rated to around 150°C with better shock-load and high-temperature capability. Both are AIMS's default recommendation for general industrial use — the baseline every other grease thickener in this category is compared against — but neither is compatible with Polyurea Grease, so mixing the two during relubrication risks breaking down the grease structure (see Grease Compatibility).
Read AIMS's full Grease Selection Guide: Types, NLGI & EP →
Shop AIMS's range of greases →
What Is Load Restraint?
Load restraint is the practice — and, in Australia, the legal obligation under the Heavy Vehicle National Law's Chain of Responsibility framework — of securing cargo on a vehicle or trailer so it can't shift or fall during transport. AS/NZS 4380 governs the tie-down equipment itself (ratchet straps, chains, webbing) and requires it to be rated in Lashing Capacity (LC), not the Working Load Limit (WLL) figure used for lifting gear — a strap marketed with a WLL rating instead of an LC rating is technically non-compliant labelling under the standard, even though WLL figures are common in the Australian market. Getting this wrong isn't just a paperwork issue: it's one of the more commonly enforced CoR failure points, since it implicates whoever loaded and secured the vehicle, not only the driver.
Read AIMS's full Ratchet Strap Guide → for AS/NZS 4380, LC vs WLL and duty-rating selection
Shop AIMS's range of load restraints →
What Is a Lock Bolt?
A lock bolt is a two-piece structural fastening system — a grooved pin and a matching swaged collar — that's installed by pulling the pin while a tool swages (radially compresses) the collar into the pin's grooves, creating a permanent, high-strength mechanical lock with no threads, no torque-dependent clamp force, and no risk of the joint backing off under vibration.
Lock bolts are the structural-fastening step up from a Structural Rivet: where a bulb-type structural blind rivet already exceeds a standard pop rivet's strength, a true lock bolt system exceeds even that again, and is specified in heavy structural steel, bridge and crane fabrication, and other genuinely safety-critical joints where a threaded bolt's risk of loosening isn't acceptable. *(General fastening-industry terminology — no dedicated AIMS article for lock bolts specifically as a distinct system from structural rivets.)*
What Are Locking Pliers?
Locking pliers are pliers with a toggle-lock jaw mechanism that clamps and holds a workpiece or fastener without needing continued hand pressure — squeeze the handles until the jaw locks, and a release lever or a second squeeze frees it again.
Five jaw geometries cover most trade uses: curved-jaw (general-purpose gripping on round or irregular stock), straight-jaw (flat, parallel-faced work), needle-nose (fine, delicate or awkward-access gripping), sheet-metal (wide, flat jaws that clamp panel edges without denting), and welding-clamp (long-reach jaws that hold two workpieces in alignment for tacking). See Vise-Grip® for how this tool type got its now-genericised trade name.
Read AIMS's full Locking Pliers Guide →
What Is Loctite?
Loctite is a genericised brand name — trademarked by Henkel — for anaerobic threadlocking adhesive, and by extension the whole family of anaerobic and related adhesive/sealant products (threadlockers, retaining compounds, thread sealants, cyanoacrylates) that carry the Loctite name. The company was founded by Vernon and Robert Krieble on the discovery of anaerobic cure chemistry, and Henkel fully acquired the brand in 1997.
In everyday trade conversation, "Loctite" is often used the way "Kevlar" or "WD-40®" is — as the brand name standing in for the whole category, even when a specific product from another manufacturer would technically be what's meant. See Anaerobic Adhesive for the underlying chemistry, and Threadlocker Colour Grades and Wicking Grade for the specific product families.
Shop AIMS's range of Loctite adhesives & thread sealants →
What Is LOTO? (Lockout/Tagout)
LOTO stands for lockout/tagout — the procedure for isolating a piece of plant or equipment from all its energy sources and physically locking that isolation in place before anyone works on it, preventing an unexpected start-up that could cause serious injury.
The standard six-step sequence is: identify all energy sources, shut down using normal controls, operate the isolating device, apply a personal padlock and a danger tag, dissipate any stored energy (bleeding pressure, discharging capacitors, blocking loads), then verify isolation by testing for absence of energy. The core rule that makes the whole system work is simple — your padlock, your key, no exceptions: a lock or tag is never removed by anyone except the person who applied it, and there's no master key.
Read AIMS's full Lockout Tagout (LOTO) Guide →
Shop AIMS's range of lockout tagout equipment →
What Is Low Carbon Steel?
Low carbon steel (up to about 0.25% carbon, equivalent to Mild Steel) is soft, ductile, easy to weld and machine, but can't be hardened significantly by heat treatment alone, unlike the stronger Medium Carbon Steel.
Higher carbon content increases strength and hardenability but reduces weldability and ductility — the trade-off runs consistently through the whole carbon-steel family.
Read AIMS's full Steel Grades Comparison Chart →
What Is LPG? (Liquefied Petroleum Gas)
LPG — Liquefied Petroleum Gas — is a fuel gas (mainly propane) stored under pressure as a liquid, used in oxy-fuel work as the cheaper, more widely available alternative to acetylene for cutting and heating. Burning with oxygen, LPG reaches around 2,800°C against acetylene's roughly 3,150°C, and its flame preheats a plate 30–60% slower — the main trade-off against acetylene's speed.
LPG's real limitation is that it can't gas-weld: its flame chemistry produces excess hydrogen that's unsuitable for fusion welding, so LPG is a cutting-and-heating fuel only, never a substitute for acetylene where actual gas welding or brazing is required. Where it wins is everywhere else — LPG cylinders are lighter and cheaper to run than acetylene's, it holds up to thick-plate cutting perfectly well with the right tip, and it needs no special low-pressure handling the way acetylene does (acetylene decomposes above 100 kPa; LPG has no such ceiling). An LPG setup needs its own gas-specific cutting tips and a dedicated Type 21 regulator inlet, distinct from the argon/CO₂ Type 10 fitting covered under AS 4267 — Gas Regulator Standard (Type 10 Inlet).
Read AIMS's full Oxy-Cutting & Oxy-Acetylene Guide →
Shop AIMS's Bossweld LPG regulators →
What Is a Lubricant?
A lubricant is any substance formulated to reduce friction and wear between surfaces in motion — the broad category that Grease, oils, Penetrating Oil, Silicone Spray and PTFE (Teflon) Dry Lubricant Spray all sit under, each suited to a different combination of load, speed, temperature and environment. A liquid lubricant flows continuously into and out of a contact area (and needs a seal or housing to stay put); a grease stays in place by design; a dry-film lubricant leaves a solid low-friction coating behind once its carrier solvent evaporates.
Shop AIMS's range of lubrication products →
M
What Is a Magnetic Drill (Mag Drill)?
A magnetic drill (mag drill, mag base drill) is a portable drilling machine with three integrated parts — an electromagnet base, a vertical drill slide with a travel handle, and a drilling motor and arbor that accepts an Annular Cutter — built to bring precision drilling to steel that can't be moved to a benchtop Drill Press: beams already set in a bridge, columns standing in a building, plate already welded into a vessel. The electromagnet's hold force depends directly on the steel's thickness, surface condition and contact area with the base, and there's a hard practical floor: a minimum of 6–8mm of ferrous steel is needed under the magnet for full holding force, with hold force dropping to roughly 40–50% of rated capacity at exactly 6mm, and the magnet releasing outright under cutting torque on thin 3–4mm sheet — a genuine safety limit, not just a performance one. Typical on-site use covers structural steel drilling, vertical column work (rigged with a safety chain as backup), overhead drilling, and large-diameter (25mm+) holes through thick plate that would be impractical to twist-drill in place.
Read AIMS's full Magnetic Drill Guide → for hold-force limits and on-site use cases
Shop AIMS's range of magnetic drills →
What Is the Major Diameter? (Thread)
Major diameter is the largest diameter of a screw thread, measured across the crests of an external thread (or the roots of an internal thread) — effectively the nominal size a bolt is named after (an M12 bolt has a 12 mm major diameter), as distinct from the thread's Minor Diameter.
The gap between major and minor diameter is a direct function of thread depth, which is why a fine-pitch thread (shallower thread depth for the same major diameter) has a *larger* minor diameter and, in most cases, marginally higher tensile strength than its coarse-pitch equivalent at the same nominal size. AIMS's own metric bolt sizing guide gives worked minor-diameter figures for both coarse and fine pitch at common sizes.
Read AIMS's full Metric Bolt Size Guide → for major/minor diameter and pitch tables by size
What Is Malleable?
Malleability is a material's ability to be hammered, pressed or rolled into a different shape — usually flat or thin — without cracking, under compressive rather than tensile force.
It's closely related to but distinct from Ductility: ductility is about stretching under tension (like drawing wire), while malleability is about deforming under compression (like hammering sheet). Most ductile metals are also reasonably malleable, but the two properties are tested and discussed separately in materials engineering.
What Is a Mallet?
A mallet is a soft-faced striking tool — rubber, nylon, rawhide or wood-headed — for driving or shaping a workpiece without marking the surface, the same underlying purpose as a Soft-Face Hammer, with "mallet" the more common everyday name for the woodworking- and general-assembly-oriented versions specifically.
A wooden mallet remains the standard tool for driving a wood chisel, where a metal hammer risks splitting the chisel handle, and a rubber or rawhide mallet is the standard choice for seating a bearing, bush or panel into place without denting it.
Shop AIMS's range of Thor mallets & hammers →
What Is a Mancooler?
A mancooler is a large, heavy-duty floor or trolley-mounted fan — typically 600–900 mm blade diameter — built to deliver a concentrated, high-velocity stream of air at one specific work area or person, rather than circulate air across a whole building the way an HVLS Fan does.
Australian-manufactured mancoolers are built around robust steel construction, with three-phase motor options on the larger units for continuous duty in foundries, fabrication shops and mining workshops — genuinely different from a domestic-style pedestal fan, which oscillates and spreads a gentler airflow rather than pushing a focused, high-velocity column at one spot. AIMS doesn't currently stock a dedicated mancooler product line — larger units on a Three-Phase Fan/Heater Supply are sourced through AIMS's specialist supplier network rather than held as standard stock, the same arrangement used for combustion heaters.
Read AIMS's full Industrial Cooling Guide →
What Is a Mandrel?
A mandrel is the central pin or rod that a blind rivet or rivet nut installation tool pulls through the fastener body to set it — as the mandrel is drawn back, it forces the body to expand, deform or bulge on the blind side of the material, clamping the joint, and (on a standard blind rivet) then snaps off once the set is complete.
On a rivet nut specifically, the mandrel threads into the nutsert's own internal thread rather than passing through it, so pulling the mandrel draws the body up against the Anvil above and collapses it into a clamping shoulder rather than breaking off — the mandrel is then unscrewed and reused for the next fastener, unlike a standard blind rivet's mandrel, which is single-use and ejected.
Read AIMS's full Rivet Nut Guide → for mandrel selection by thread size
What Is Martensite?
Martensite is the hard, brittle crystal structure that forms in steel when it's rapidly cooled (quenched) from the Austenite phase — it's the structure responsible for the high hardness of quenched, unhardened steel, before tempering softens it back to a usable toughness.
Steel straight out of the quench tank is martensitic, extremely hard, and too brittle to use as-is in most applications — that's why quenching is always followed by tempering, which trades away some hardness for the toughness needed to survive in service. This is background heat-treatment terminology rather than a buying spec, but it's the reason "quenched and tempered" always appears as a pair.
What Is a Master Link?
A master link is the single large ring at the top of a multi-leg Chain Sling, which connects all the individual sling legs to the crane hook or lifting point. It's the load-bearing hub the whole sling hangs from, so it's rated and inspected as carefully as the chain itself.
Shop AIMS's range of wire rope, chain & fittings →
What Is Max. Grip / Min. Grip? (Rivet & Nutsert Rating)
Max. grip and min. grip are the two boundary figures that define a fastener's Grip Range above — the maximum and minimum material stack thickness a specific rivet or rivet nut can reliably clamp. Sizing below min. grip leaves the fastener unable to develop a proper set (it spins or sits loose); sizing above max. grip means the installation tool can't pull the mandrel far enough to complete the set before it strips.
Manufacturers publish these two figures for every rivet and rivet nut size specifically so installers can measure the actual material stack first and select the correct fastener length and grip range for it, rather than guessing. *(General fastening-industry terminology, part of AIMS's own rivet nut grip-range guidance.)*
What Is a Mechanical Fastener? (Conveyor Belt)
A mechanical fastener is a metal (or heavy-duty plastic) splice joining two conveyor belt ends by clamping, stapling or bolting fastener plates across the join, rather than fusing them together — commonly sold as clipper-style lacing, installed with a purpose-made lacing/crimping tool.
It's the fast, low-cost way to join or repair a belt: no curing time, no specialist crew, and the belt can be back in service within minutes of the fasteners being fitted — the standard choice for workshop repairs, belts that get shortened or re-spliced regularly, and older or worn belting that's no longer a good candidate for vulcanising. The trade-off against an Endless Splice is joint strength and smoothness: a mechanical fastener typically holds a lower percentage of the belt's full rated strength than a vulcanised joint, the metal plates can snag on Skirting (Skirt Board, Conveyor) or a Belt Scraper (Conveyor Cleaner) blade if not set correctly, and the join point is a visible, monitorable wear item rather than a seamless one — genuinely useful when that visibility is exactly what's wanted on a belt under regular inspection. AIMS's own conveyor components guidance lists the clipper lacing kit as the standard tool for this style of workshop-level join.
Shop AIMS's range of conveyor components & steel rollers →
What Is Medium Carbon Steel?
Medium carbon steel (roughly 0.30–0.60% carbon) is stronger than Low Carbon Steel and can be hardened by heat treatment, but is harder to weld without preheating or post-weld treatment to avoid cracking.
Higher carbon content increases strength and hardenability but reduces weldability and ductility. AISI 1045 is a common medium-carbon grade used for shafts and machine parts where some hardenability is needed but full alloy-steel cost isn't justified.
Read AIMS's full Steel Grades Comparison Chart →
What Is MEPS (Minimum Energy Performance Standards)?
MEPS (Minimum Energy Performance Standards) is the Australian regulatory scheme that sets a mandatory minimum efficiency level for products including electric motors — for three-phase motors between 0.73 kW and 185 kW, that minimum is currently IE Efficiency Class IE3, meaning a motor sold below that threshold generally can't legally be supplied as a standard catalogue item in Australia. It's a compliance floor rather than a performance target — many applications are still better served by stepping up to IE4 where the duty cycle justifies it.
What Is Metric (Measurement System)?
Metric describes the internationally standardised decimal system of measurement — metres, kilograms, newtons, pascals — that Australia officially adopted in the 1970s and that now governs virtually all current AU engineering standards, fasteners and drawings. See Imperial above for how the older system persists in legacy and imported equipment, and SI below for the formal unit standard metric is built on. AIMS's product range and specifications default to metric throughout, with imperial stocked specifically where legacy or imported equipment demands it.
What Is a Micrometer (Outside Micrometer)?
An outside micrometer measures external dimensions — shaft diameters, part thickness, bar stock — via a precision screw mechanism: an anvil and spindle close around the workpiece, with one complete rotation of the thimble moving the spindle exactly 0.5mm. Standard micrometers read to 0.01mm resolution (each of the thimble's 50 graduations equalling 0.5mm ÷ 50), which suits most workshop applications; higher-spec models reach 0.001mm resolution via a vernier scale or digital display. In practice, a correctly zeroed, well-maintained 0.01mm micrometer in good hands is typically accurate to about ±0.005–0.010mm under normal workshop conditions. AIMS's guide covers five distinct types beyond the standard outside micrometer: inside (internal bore diameter, groove width), bore (3-point) (cylinder bore diameter with a roundness check built in), depth (hole, slot and shoulder depth) and thread (pitch diameter verification on external threads) — each addressing a distinct measurement geometry the plain outside type can't reach.
Read AIMS's full Micrometer Guide → for all five micrometer types and reading technique
Shop AIMS's range of micrometers →
What Is MIG? (Welding)
MIG — Metal Inert Gas — welding feeds a continuous solid wire electrode through a torch while a shielding gas blankets the weld pool, protecting it from atmospheric contamination as the arc melts the wire and fuses it into the joint. It's a semi-automatic process: the machine feeds the wire at a set speed, and the welder controls torch angle, travel speed and position. MIG is the everyday trade name for the process; its formal engineering designation is GMAW (Gas Metal Arc Welding) — the same process, two names.
MIG is the process most Australian workshops learn first and reach for most often, because the continuous wire feed makes it faster and more forgiving than SMAW / MMA (Stick Welding) and considerably easier to master than TIG. Gas MIG runs on DCEP / DCEN (Welding Polarity) — specifically DCEP — with a Shielding Gas matched to the base metal (typically a 75%/25% argon/CO₂ blend for mild steel), while gasless flux-cored wire runs the opposite polarity, DCEN. Getting that polarity wrong is one of the most common beginner mistakes and produces a cold, spattery, poorly fused weld.
Read AIMS's full MIG Welding Guide and MIG vs TIG vs Stick Welding Guide →
Shop AIMS's range of MIG welders, MIG wire and MIG consumables →
What Is a Mild Steel?
Mild steel is a low-carbon steel (up to about 0.25% carbon) that's easy to weld, machine and form, but not through-hardenable the way medium- or high-carbon steels are. It's the default, general-purpose steel used across construction, fabrication and general engineering wherever high strength or wear resistance isn't the priority.
In Australian trade use, "mild steel" and Low Carbon Steel overlap — mild steel sits at the low-carbon end of that range (AISI 1006–1025 equivalents), below Medium Carbon Steel. It's supplied as round bar, flat bar, plate and sheet, and takes weld, paint and zinc coatings well because it lacks the higher carbon content that makes weld zones brittle in harder grades.
Read AIMS's full Steel Grades Comparison Chart →
Shop AIMS's range of raw materials →
What Is the Minor Diameter? (Thread)
Minor diameter is the smallest diameter of a screw thread, measured across the roots of an external thread (or crests of an internal thread) — the diameter that actually determines the thread's tensile stress area and therefore its real strength, as distinct from the thread's Major Diameter.
A fine-pitch thread (shallower thread depth for the same major diameter) has a *larger* minor diameter and, in most cases, marginally higher tensile strength than its coarse-pitch equivalent at the same nominal size. AIMS's own metric bolt sizing guide gives worked minor-diameter figures for both coarse and fine pitch at common sizes.
Read AIMS's full Metric Bolt Size Guide → for major/minor diameter and pitch tables by size
What Is Moisture Cure?
Moisture cure is a cure mechanism that reacts with atmospheric moisture and needs air exposure to cure at all — used by RTV silicone and single-part PU (Polyurethane). It's the opposite trigger from Anaerobic Cure, which needs the absence of air.
Getting this backwards explains most cure failures in the field: a moisture-cure product sealed away from air won't cure properly.
Read AIMS's full Industrial Adhesive Types Guide →
What Is a Molly® (Molly Bolt / Hollow-Wall Anchor)?
A Molly® bolt is a hollow-wall anchor that expands behind a plasterboard or hollow panel as its screw is tightened, spreading legs or a sleeve out against the back of the board to grip it from behind — a permanent, relatively high-strength fixing option for a wall type too thin and hollow for a standard masonry wall plug.
"Molly" is a genericised trademark, in the same category as "Nyloc®" and "Rivnut" — used generically across the trade for this general style of expanding hollow-wall anchor rather than one specific manufacturer's product. AIMS's own wall-fixing guide places Molly bolts among the stronger plasterboard options, generally ahead of a self-drilling plasterboard plug but behind fixing directly into a wall stud where load allows it.
Read AIMS's full Wall Plug Guide → for hollow-wall anchor options and load capacities
Shop AIMS's range of masonry & concrete anchors →
What Is Moly Grease (Molybdenum Disulfide / MoS2)?
Moly grease is a conventional grease base with molybdenum disulfide (MoS2) — a naturally occurring mineral, milled to a very fine 1–5 micron particle size — suspended in it at around 1–5% concentration. MoS2 works through a lamellar barrier mechanism: its hexagonal layered crystal structure lets sheets slide over each other under pressure at an extremely low friction coefficient (around 0.025, against 0.6–0.8 for unlubricated steel-on-steel), which is why AIMS's own guide recommends it specifically for slow-speed, heavily loaded metal-on-metal joints — excavator bucket and boom pins, fifth-wheel truck couplings, kingpins, open gears and slew rings, splines under high torque.
AIMS's own guide is equally direct about where not to use it: never on sintered bronze or sintered iron bearings, since the MoS2 particles permanently block the pores those bearings rely on for self-lubrication; not on high-speed rolling bearings, where the particles abrade the raceway; and not in sustained wet or submerged conditions, where MoS2 slowly oxidises into an abrasive, corrosive byproduct — Calcium Sulfonate (Complex) Grease is the better choice for a wet, heavily loaded application. Continuous service temperature is set by the base grease at around 120°C, not by the MoS2 itself, which is stable to far higher temperatures on its own.
Read AIMS's full Moly Grease Guide: MoS2, Applications & When Not to Use It →
Shop AIMS's range of Molybond lubricants →
What Is a Motor Enclosure Type (TEFC/ODP/TEAO/TENV)?
Motor enclosure type describes how a motor's housing is sealed and cooled, and it's a separate spec from IP Rating (Ingress Protection) — closely related, but IP rating measures ingress protection while enclosure type describes the cooling method that rating is built around. TEFC (Totally Enclosed Fan Cooled) is the standard default for virtually all Australian industrial applications: a fully enclosed housing with an external fan on the non-drive end drawing air over the cooling fins, typically rated IP55–IP66. ODP (Open Drip-Proof) uses a ventilated housing that allows air to circulate directly through the motor — better cooling and lower cost, but only suitable for clean, dry indoor locations (typically IP23), and rarely specified outside purpose-built clean-room equipment.
Two less common types cover specific situations: TEAO (Totally Enclosed Air Over) relies on cooling airflow from the driven equipment itself — a direct-mounted fan or blower blade — rather than its own fan; TENV (Totally Enclosed Non-Ventilated) has no cooling fan at all, relying on surface radiation instead, and suits low-speed or VFD (Variable Frequency Drive)-controlled applications running sustained low speed, where a standard TEFC motor's own cooling fan becomes ineffective below roughly 25–30Hz. A fifth type, Explosion-Proof (Ex/EXD), is a heavy-duty sealed enclosure for hazardous areas (Zone 1/Zone 2) rather than a general-duty rating.
Read AIMS's full Electric Motor Guide → for the full enclosure type comparison table
Shop AIMS's range of electric motors →
What Is Motor Frame Size (IEC / AS/NZS 1359)?
Motor frame size, standardised under IEC and AS/NZS 1359, is a numbering system that defines an electric motor's shaft centreline height and mounting dimensions — frame sizes run from around 56mm up to 315mm and beyond, with common sizes like 90L, 112M, 160M and 315M each corresponding to a typical power range. The point of the standard is interchangeability: two motors of the same frame size and mounting type (see Motor Insulation Class and mounting configuration B3/B5/B14) are dimensionally interchangeable regardless of manufacturer, which is what makes a like-for-like motor replacement possible without re-engineering the mounting.
What Is Motor Insulation Class — F & H?
Motor insulation class specifies the maximum temperature an electric motor's winding insulation is rated to withstand continuously — Class F is rated to 155°C and is the standard for most industrial motors, while Class H is rated to 180°C for higher-temperature or more demanding duty applications. Many Class F-insulated motors are actually designed to run at the lower Class B temperature rise (130°C) in normal operation, which builds in a thermal safety margin that meaningfully extends motor life rather than running the insulation right up to its rated limit.
What Are Motor Poles and How Do They Set Motor Speed?
A motor's poles are magnetic pairs set up inside it by the placement and connection of the stator Winding — the pole count is fixed at manufacture and is the primary factor that sets a motor's base speed. In Australia, on the standard 50Hz supply, pole count and synchronous speed follow a fixed relationship: 2-pole = 3,000 RPM synchronous (≈2,850–2,900 RPM actual full-load speed); 4-pole = 1,500 RPM synchronous (≈1,400–1,450 RPM actual — by far the most common configuration in general industrial use); 6-pole = 1,000 RPM synchronous (≈940–960 RPM actual); 8-pole = 750 RPM synchronous (≈700–720 RPM actual).
This AU (50Hz) table is genuinely different from the 60Hz figures most online references and US-origin documentation quote by default — a 4-pole motor runs at 1,800 RPM synchronous in the US but 1,500 RPM synchronous in Australia, so a nameplate or spec sheet pulled from a US source needs the pole-to-speed relationship re-checked against local 50Hz figures, not assumed. The gap between the synchronous speed above and the actual full-load speed is Slip (Motor). Fitting a VFD (Variable Frequency Drive) gives infinitely variable speed control from a single motor, rather than needing to select a different pole count for a different fixed speed.
Read AIMS's full Electric Motor Guide → for the complete pole/speed/application reference table
Shop AIMS's range of electric motors →
What Is Mousing (Rigging)?
Mousing is the practice of tying, taping or wiring across the open throat of a hook — typically a crane hook without its own spring safety latch — to physically prevent the sling or chain from slipping out of the hook under slack-line conditions. It's a low-cost, low-tech safeguard, but it's not a substitute for a proper Safety Latch; where a hook has a functioning latch, mousing on top of it is usually unnecessary and can be a sign the latch itself needs inspecting.
What Is MRO? (Maintenance, Repair & Operations)
MRO stands for Maintenance, Repair and Operations — the category of products and activities involved in keeping equipment, facilities and plant running, as opposed to the raw materials and components that go directly into a manufactured product.
It's the category most of what AIMS supplies actually sits in: bearings, fasteners, cutting tools, abrasives, adhesives, safety & PPE, lifting equipment, pneumatics, welding consumables and lubricants are all classic MRO items — bought not because they become part of a finished product for sale, but to keep a business's own equipment and operations running. MRO spend is typically managed differently from production-material spend, often through a dedicated maintenance budget, stores/inventory system and preferred-supplier arrangement, because it tends to be high-frequency, lower-value and less predictable than production purchasing.
What Is MRP? (Material Requirements Planning)
MRP stands for Material Requirements Planning — a production-planning and inventory-control system that works backwards from a manufacturing schedule to calculate exactly what materials and components are needed, in what quantities, and by when, so production doesn't stall waiting on stock.
MRP systems (often part of a broader ERP platform) use a bill of materials, current inventory levels and lead times to generate purchase and production orders automatically, rather than relying on guesswork or simple reorder points. Worth a quick disambiguation: outside Australia — India in particular — "MRP" more commonly means Maximum Retail Price, a printed ceiling price on packaged goods. That usage doesn't really apply here; in Australian trade and manufacturing conversation, MRP almost always means the planning system, while the equivalent Australian pricing concept is usually called RRP (Recommended Retail Price) instead.
What Is MS Polymer? (Modified Silicone)
MS Polymer (modified silicone) is a hybrid adhesive-sealant that combines the flexibility and weatherability of silicone with the paintability of PU (Polyurethane) — unlike standard RTV silicone, it can be painted once cured, and unlike some polyurethanes, it contains no solvents or isocyanates.
It also holds up better to UV exposure than standard silicone or polyurethane on their own, which is why it's increasingly specified for exterior sealing jobs where both paintability and long-term weather resistance matter — a genuine "best of both" compromise rather than a downgrade of either parent chemistry.
Read AIMS's full Industrial Adhesive Types Guide →
Shop AIMS's range of adhesives, sealants & tapes →
What Is MVP? (Minimum Viable Product)
MVP stands for Minimum Viable Product — a version of a new product or offering built with just enough features to be genuinely usable, released early to real customers so a business can test demand and gather feedback before investing further.
The idea originated in software and startup circles, but it applies just as well to a physical product line, a new service offering or a private-label range: rather than spending months perfecting every detail before launch, an MVP gets a workable version to market fast, then improves it based on what customers actually do and say. It's a genuinely useful concept for any business considering White-Labelling or launching a new product range, though it sits more on the product-development and business-strategy side of things than the day-to-day trade vocabulary most of this glossary covers.
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What Is NATA?
NATA (National Association of Testing Authorities) is Australia's national accreditation body for testing and calibration laboratories. NATA accreditation — assessed against the international standard ISO/IEC 17025 — is the benchmark Australian industry looks for when it needs a Calibration certificate that will actually hold up under audit or against a customer's quality-system requirement, since it verifies both the lab's competence and the unbroken Traceability (Calibration) chain behind the certificate.
Read AIMS's full guide to calibration intervals → for what NATA accreditation actually covers
What Is NB? (Nominal Bore)
NB (nominal bore) is the standard size designation for pipe and pipe fittings in Australia — a rounded reference number that names a pipe's approximate internal diameter without being its exact measured diameter, the same way a "10mm" spanner isn't machined to precisely 10.000mm.
NB is the metric-era term for what older documentation and some imported equipment still calls "nominal pipe size" or references by schedule — the actual wall thickness and true internal diameter for a given NB size still depend on the pipe's schedule (its wall-thickness rating), so two pipes sharing the same NB figure can have genuinely different bores if their schedules differ.
What Is NBR? (Nitrile Rubber)
NBR (nitrile rubber, also called Buna-N) is a synthetic rubber with excellent resistance to oils, fuels and hydraulic fluids, workable from about -40°C to +100°C — making it the default seal and gasket material anywhere petroleum products are involved.
Its weak point is hot water and steam: NBR degrades (hydrolysis) above about 70°C, and it's destroyed by brake fluid (DOT 3/4). The simple rule that governs most seal and gasket selection: oil-side service favours NBR, water-side service favours EPDM (Ethylene Propylene Diene Monomer) — using the wrong one is one of the most common preventable seal failures in the trade.
Read AIMS's full O-Ring Guide →
Shop AIMS's range of oil seals & O-rings →
What Are Needle Nose Pliers?
Needle nose pliers have long, slender, tapered jaws built for fine, precise gripping in tight or awkward spaces — bending wire, retrieving a dropped small part from inside an enclosure, or holding a small component steady for soldering — where a Combination Pliers's wider jaw simply can't reach or can't grip precisely enough.
Most needle nose pliers also carry a cutting edge near the pivot, the same dual-function layout as combination pliers, so the choice between the two usually comes down to jaw geometry for the job at hand rather than one replacing the other outright.
Read AIMS's full Types of Pliers Guide →
Shop AIMS's range of mixed plier sets →
What Is a Needle Roller Bearing?
A needle roller bearing uses long, thin cylindrical rollers — a length-to-diameter ratio of at least 4:1, often 10:1 or higher — to pack high radial load capacity into a compact radial section, exactly where a standard roller or ball bearing wouldn't physically fit. AIMS's own guide splits them into caged types (needles separated by a steel, brass or polymer cage — smoother, and able to run at roughly double the limiting speed of a full-complement bearing) and full-complement types (no cage, maximum needle count and load capacity, lower speed limit from needle-on-needle contact).
Standard needle bearings carry radial load only; purpose-built thrust needle bearings (AXK series) and combined radial-plus-thrust types (NAX, NAXR series) add axial capacity for automotive transmissions and machine-tool spindles.
Read AIMS's full Needle Roller Bearing Guide: Types, Sizes & Applications →
Shop AIMS's range of needle roller bearings →
What Is a Needle Valve?
A needle valve uses a slender, tapered needle-shaped point threading down into a matching conical seat, giving extremely fine, precise control over flow — the long, gradual taper means a full turn of the handle changes flow only slightly, unlike a Ball Valve or Gate Valve, where the same turn swings between fully open and fully shut in a fraction of a rotation.
That fine-adjustment characteristic is exactly why needle valves dominate low-flow, high-precision duty rather than general isolation: instrumentation and gauge lines (bleeding a pressure gauge down slowly rather than snapping it open), calibration rigs, sampling points, and any pneumatic or hydraulic circuit where a technician needs to dial in an exact, repeatable flow rate rather than just turn something on or off. They're a poor choice for general shutoff duty on larger pipework, both because their long taper creates a comparatively high pressure drop even fully open, and because the fine thread pitch that gives such precise control also makes a needle valve slow and impractical to operate as a simple stop valve. See Throttling Valve for the broader category of valves purpose-built for metering flow rather than just isolating it.
What Is Neoprene? (Polychloroprene)
Neoprene (polychloroprene, CR) is a general-purpose synthetic rubber that sits between NBR (Nitrile Rubber) and EPDM (Ethylene Propylene Diene Monomer) in chemical resistance — better than NBR on weather and ozone exposure, better than EPDM on mild oil contact, without excelling at either extreme. It works across roughly -40°C to +100°C.
That balanced, middle-ground performance is exactly why it's used in HVAC duct gaskets, marine sealing, refrigerant service and electrical jacketing — applications with a mix of moderate oil and moderate weather exposure where a single-purpose material like NBR or EPDM would be the wrong trade-off.
Read AIMS's full Rubber Sheet Guide →
Shop AIMS's range of rubber sheets & rolls →
What Is a Nitto-Style Coupler? (Quick-Coupler Profile)
A Nitto-style coupler is the dominant quick-connect air fitting profile in Australian pneumatic trade: a smooth cylindrical socket body with a spring-loaded outer locking sleeve, mating with a flat-nosed cylindrical plug tip. Genuine Nitto — Japanese-made, in plated steel or stainless — is the quality benchmark; the geometry has been widely cloned by other brands, with quality varying considerably between them (cheap clones are the usual culprit behind a locking sleeve that jams or a socket that slowly starts to weep).
The distinction worth knowing before you buy: Ryco-style is the other coupler profile still seen and stocked in the AU trade, but genuine Ryco has exited the market, so what's sold today as "Ryco-style" or "Ryco-compatible" are clones built to the original Ryco geometry rather than a current OEM product. The two profiles are not interchangeable — a Ryco-style plug will often only half-engage in a Nitto-style socket and won't lock reliably, so plug and socket must be matched to the same profile throughout a workshop's airline, or a dedicated Nitto-to-Ryco adapter used at the changeover point. Jamec-branded couplers (sometimes marked PEM) aren't a third incompatible standard — they're manufactured to match one profile or the other, so check which before ordering. Genuine Nitto is the safer default to standardise a workshop on, since it's the most widely stocked profile in Australia. See QC for the general quick-connect concept and Push-to-Connect (One-Touch) Fitting for the different, permanent style of fitting used inside a pneumatic circuit rather than at a tool station.
Read AIMS's full Pneumatic Fittings & Air Line Components Guide → for coupler bore sizes and high-flow variants
Shop AIMS's range of pneumatic tools & air line fittings →
What Is NLGI Grade?
NLGI grade is the National Lubricating Grease Institute's consistency classification for grease, running from 000 (semi-fluid) through to 6 (hard, block-like), measured by the ASTM D217 cone penetration test at 25°C. AIMS's own guide positions NLGI 2 as the default for most rolling-element bearings — a "smooth" consistency comparable to peanut butter — with softer grades reserved for low-temperature or centralised-lubrication systems and harder grades for specific sealed or high-temperature applications.
This is a distinct sense of "grade" from VG (Viscosity Grade) — VG classifies an oil's flow resistance, NLGI classifies a grease's physical consistency — worth cross-referencing rather than merging, per the existing Grade disambiguation note in this glossary.
Read AIMS's full Grease Selection Guide: Types, NLGI & EP →
Shop AIMS's range of greases →
What Is Nomex?
Nomex is DuPont's registered trademark for its meta-aramid fibre, developed for inherent flame resistance — it doesn't melt or drip when exposed to flame and remains protective at temperatures up to roughly 370°C.
Where Kevlar® (para-aramid) is chosen primarily for cut and puncture resistance, Nomex is chosen primarily for heat and flame resistance, and the two are genuinely different aramid chemistries rather than the same fibre under two names. Nomex-family fabrics and knits turn up in flame-resistant workwear and heat-protective glove linings.
What Is a Non-Rising Stem Valve? (NRS)
A non-rising stem (NRS) valve's stem rotates internally without changing height, making it the compact, buried-service choice for water mains and low-headroom installations where a Rising Stem Valve simply wouldn't have clearance — the trade-off is that NRS valves require clean fluid, since debris around the internal stem-and-gate thread connection can jam the mechanism in a way a rising-stem design's external, accessible threads don't.
A specific, genuinely dangerous failure mode applies to both rising and non-rising stem designs: a broken stem can leave the gate dropped into the closed position while the handwheel still turns freely and appears to show "open" — meaning the position indication itself has failed. Testing actual flow after any over-torqued gate valve, rather than trusting the handwheel position, is the only reliable check.
Read AIMS's full Gate Valve Guide →
What Is Nonferrous Metal?
Nonferrous means everything that isn't iron-based — aluminium, brass, copper, bronze and stainless steel with very low iron content in relative terms are all typically grouped as nonferrous in trade conversation, though stainless steel is technically iron-based too, as distinct from Ferrous.
Most nonferrous metals are non-magnetic and naturally corrosion-resistant, unlike ferrous metals, which are generally magnetic and prone to rust without protection. Cutting discs and blades are usually specified separately for ferrous versus nonferrous material because the two behave very differently under a cutting edge.
What Is a Nose Assembly? (Nosepiece)
The nose assembly (nosepiece) is the interchangeable front section of a rivet gun or rivet nut tool that actually contacts the fastener during setting — on a blind rivet gun, a set of jaws that grip the mandrel stem; on a rivet nut tool, the Anvil and mandrel assembly matched to a specific thread size.
Nosepieces are swapped to match different rivet or rivet nut sizes, and their condition matters directly to install quality: AIMS's own rivet gun guide notes that "quality jaws bite the mandrel cleanly and pull straight, while cheap jaws slip and chew the stem" — a worn or poor-quality nosepiece is a common cause of inconsistent sets and jammed tools.
Read AIMS's full Rivet Gun Guide → for nosepiece types by rivet gun style
Shop AIMS's range of pop rivet guns & nut riveters →
What Is NPT? (National Pipe Thread)
NPT (National Pipe Thread) is the American tapered pipe thread standard, using a 60° included thread angle against BSP's 55° — a difference small enough that an NPT and a BSPT fitting will often physically thread together, but large enough that they will not seal correctly once pressurised.
This is a genuine, common and expensive mistake on imported American equipment fitted into an Australian pipe system: the mismatch isn't obvious on inspection, the fitting goes together under hand pressure, and the failure only shows up as a leak or a blown seal once the system is pressurised — checking the thread standard before assembly, not after a leak, is the only reliable safeguard.
Read AIMS's full Hydraulic Fittings Guide →
Shop AIMS's range of hydraulic fittings →
What Is a Nut Driver?
A nut driver is a fixed-shank hand tool — essentially a screwdriver with a hex socket instead of a blade — for manually driving a hex-head screw or bolt where a power tool isn't wanted or available.
It suits precise, low-torque manual work best. Against a magnetic Nutsetter, built for repetitive power-tool driving of one common size, and a Socket-on-Hex Adapter, which trades some speed for size flexibility from an existing socket set, a nut driver is the manual, single-purpose option of the three. *(General hand-tool terminology — no dedicated AIMS article for the nut driver specifically, since AIMS's own guide covers the magnetic nutsetter.)*
What Is a Nutsert?
A nutsert (rivet nut, Rivnut®) is a threaded insert installed from one side of a panel, creating a permanent internal thread in sheet material, tube or any base too thin to tap a thread into directly — see Rivnut / Rivet Nut (Threaded Insert) below for the full detail on types, grip range and installation.
Nutsert is essentially interchangeable with rivet nut in Australian trade usage, with "Rivnut" as the genericised trademark version of the same product (originally a Bollhoff brand name, now used generically much like "Nyloc®" or "Molly"). All three terms point to the same underlying fastener family.
Read AIMS's full Rivet Nut Guide → for the complete sizing, body-type and tool guide
Shop AIMS's range of rivet nuts & nutserts →
What Is a Nutsetter? (Magnetic)
A magnetic nutsetter is a power-tool bit — used in a drill or impact driver, with a built-in magnet that holds the fastener in place while driving a hex-head screw or bolt.
It's the fastest option of the three for repetitive power-tool driving of one common size, in contrast to a Nut Driver (a fixed-shank hand tool for manual, low-torque work) and a Socket-on-Hex Adapter (which trades some speed for size flexibility from an existing socket set).
Read AIMS's full Magnetic Nutsetter & Bit Holder Guide →
Shop AIMS's range of magnetic nutsetters →
What Is a Nyloc® (Nylon Insert Lock Nut)?
A Nyloc® nut is a hex nut with a nylon ring moulded into a recess at one end, sized slightly smaller than the bolt's thread — as the bolt threads in, it deforms the nylon insert, which grips the thread continuously and creates Prevailing Torque all the way to full seating, resisting vibration-loosening far better than a plain hex nut alone.
"Nyloc®" is a genericised trademark (originally a Simmonds brand name) now used generically across the industry the way "Nyloc-type" or "nylon insert lock nut" describes the same product regardless of maker — governed by DIN 985 (thin-body) or DIN 982 (regular height). The nylon insert has a practical temperature ceiling around 120°C, and AIMS's own guide notes that locking effectiveness diminishes with each reuse cycle — a Nyloc® is a limited-reuse fastener, not a permanent one, and should be replaced rather than reused in a critical joint.
Read AIMS's full Nyloc Nut Guide → for DIN 985 sizing and temperature limits
Shop AIMS's range of nylon lock nuts →
What Is Nylon Pneumatic Tubing? (PA Tube)
Nylon (PA11/PA12) tube is the step up from PU Pneumatic Tubing where temperature or chemical exposure rules polyurethane out — it's stiffer and less kink-friendly, but handles higher pressure (up to 10–15 bar in 6 mm PA12) and a wider working temperature range, with PA11 (often sold as Rilsan) rated as high as +100°C. Chemical resistance is excellent: fuels, oils and solvents that would soften or degrade PU tube don't touch nylon in the same way.
That makes nylon the right choice for hot compressed air lines, fuel-contact runs, and automotive or aerospace applications where PU's temperature ceiling is a genuine risk rather than a technicality. PA11 specifically also has superior hydrolysis resistance, which matters for a tube run left outdoors and exposed to Australian humidity and UV over years rather than months — a scenario where PU or Polyethylene Pneumatic Tubing would age out faster. Moderate UV resistance overall means nylon still isn't a lifetime outdoor product, but it outlasts the alternatives in that setting.
Read AIMS's full Pneumatic Fittings & Air Line Components Guide → for pressure and temperature ratings by tube grade
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What Do OD & ID Mean? (Outer/Inner Diameter)
OD (outer diameter) and ID (inner diameter) are the two dimensions that define a round or tubular part — OD is measured across the outside, ID across the inside (the bore or hole running through it) — and the two should never be assumed equal, since wall thickness is exactly what separates them. OD is usually checked with an outside Micrometer or a Calliper's external jaws; ID needs either a caliper's internal jaws, an inside micrometer, or — for higher accuracy or awkward access — a Bore Gauge. Confusing OD and ID when ordering a bush, bearing, seal, tube or hose fitting is one of the most common, and most avoidable, ordering errors in industrial supply.
What Is OE? (Original Equipment)
OE stands for Original Equipment — the parts and components a machine, vehicle or piece of equipment was originally fitted with by its manufacturer, as distinct from aftermarket or non-genuine replacement parts.
OE is the "original" half of OEM (Original Equipment Manufacturer) — the company that made the part in the first place. Specifying "OE" or "OE-equivalent" on a parts order signals that fit, quality and performance need to match what the equipment left the factory with, which matters most for safety-critical or warranty-sensitive components where a cheaper aftermarket substitute could compromise either.
What Is OEE? (Overall Equipment Effectiveness)
OEE — Overall Equipment Effectiveness — is a manufacturing KPI that measures how much of a piece of equipment's full production potential is actually being realised, combining three factors into one score: Availability (is it running when it should be), Performance (is it running at full speed) and Quality (is it producing good parts, not scrap or rework).
A perfect score of 100% OEE means a machine ran the entire scheduled time, at full speed, producing only good output — in practice, world-class manufacturers typically target 85% and most operations sit well below that. OEE is a maintenance and production-management tool rather than a product AIMS sells, but it's directly relevant to AIMS's own MRO and Equipment audience: unplanned downtime for maintenance or breakdowns is one of the biggest drags on the Availability component of the score, which is exactly what a well-stocked MRO supply chain helps protect.
What Is OEM? (Original Equipment Manufacturer)
OEM stands for Original Equipment Manufacturer — the company that designed and originally built a piece of equipment, machine or component, as distinct from a third party that later supplies replacement or compatible parts for it.
"OEM parts" means parts sourced from (or made to the exact spec of) that original manufacturer, which is the highest-confidence choice for fit and performance but not always the cheapest or fastest to source. This sits alongside OE (the original parts themselves) and Off-the-Shelf (a standard, non-custom product) as three closely related terms trade and procurement teams use constantly when deciding how to source a replacement part or component.
What Is Off-the-Shelf?
Off-the-shelf describes a standard product that's manufactured to a common specification and kept available for immediate purchase, as opposed to something custom-made or built to order.
It's the practical alternative to custom or bespoke manufacturing: an off-the-shelf bearing, fastener or fitting is faster to source and usually cheaper than a one-off custom part, provided a standard size and spec actually suits the application. Most of AIMS's own SKU-based catalogue range — bearings, fasteners, fittings and consumables in standard sizes — is exactly this kind of off-the-shelf product, which is what makes fast, reliable stock availability so valuable to trade and maintenance customers.
What Is a One-Way Screw (Clutch Head Screw)?
A one-way screw — also called a clutch head or tamper-resistant screw — has a head shaped so a screwdriver bit grips it firmly on the tightening (clockwise) turn but cams straight out on the loosening (anticlockwise) turn, making the fastener effectively irreversible with an ordinary driver.
They're specified anywhere a fastener needs to resist casual removal — public toilets, transport and playground equipment, security grilles, number plates and anti-theft fittings — and because there's no functioning drive recess left once installed, deliberate removal needs a purpose-built tool rather than a bigger screwdriver or more force. AIMS's own guide covers the four practical removal methods, ranked by success rate.
Read AIMS's full One-Way Screw Removal Guide → for step-by-step removal methods
Shop AIMS's range of one-way screws →
What Is the Optical Class for Safety Glasses? (1 / 2 / 3)
Optical class rates a safety lens's visual clarity under AS/NZS 1337.1: Class 1 is premium clarity, suited to precision work and driving; Class 2 is standard clarity, adequate for most industrial use; and Class 3 is reduced clarity, intended for short-duration use only rather than an all-day wear rating.
This is a genuinely different measurement from Impact Class — clarity and impact resistance are tested and rated separately, and a lens's Class 3 optical rating doesn't say anything about how much mechanical force it can absorb.
Read AIMS's full Safety Glasses Guide →
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What Is a Pad Eye?
A pad eye is a flat metal plate with a welded or forged eye, fixed permanently to a structure, vessel or piece of equipment to provide a dedicated lifting or lashing point. Unlike an Eye Bolt, which threads into a tapped hole and can be removed, a pad eye is a permanent structural fitting — its rated capacity depends as much on the quality of the weld and the parent structure as on the pad eye itself, which is why pad eye welds are a standard item on a rigging or lifting-plan inspection.
What Is PAPR? (Powered Air Purifying Respirator)
A PAPR is a powered respirator that uses a battery-driven blower to draw contaminated air through filters and deliver clean, positive-pressure air to a hood, helmet or facepiece — rather than relying on the wearer's own breathing effort to pull air through a filter the way a standard Respirator does.
Because a loose-fitting PAPR hood doesn't need a tight facial seal, it's the practical solution for workers with beards or facial hair who can't get a proper seal from a standard respirator mask. PAPRs are available with P2 or P3 filters depending on the hazard, and the same positive-pressure principle is used in some welding helmets for combined respiratory and eye/face protection.
Read AIMS's full Respirator & Dust Mask Guide and Welding Helmet Guide →
Shop AIMS's range of respiratory protection →
What Is Passivation?
Passivation is a chemical treatment (usually an acid bath) applied to stainless steel that removes free iron contamination from the surface and encourages the formation of a stable, protective chromium-oxide layer — the same layer that gives stainless steel its corrosion resistance in the first place.
It's a finishing step, not a way to upgrade a lower stainless grade into a higher one — passivating A2 (304) stainless doesn't give it A4 (316)-level chloride resistance. Passivation matters most where stainless parts have been machined, welded or handled with carbon-steel tools, since that contact can leave free iron on the surface that would otherwise cause surface rust spots on an otherwise corrosion-resistant part.
Read AIMS's full Stainless Steel Fastener Grades guide →
What Is PBS (Performance Based Standards)?
PBS is a national scheme that lets a heavy vehicle combination be approved against measured safety and infrastructure performance outcomes — braking distance, swept path on a corner, static rollover threshold and similar — rather than against fixed, prescriptive mass and dimension rules. It's how many of Australia's higher-productivity combinations (certain B-Double, B-Triple and road-train configurations) are approved to operate at all, since they'd fall outside the standard prescriptive limits but can demonstrably perform as safely as, or better than, a standard combination.
What Is PCBN (Polycrystalline Cubic Boron Nitride)?
PCBN (Polycrystalline Cubic Boron Nitride) is a synthetic cutting-tool material — boron nitride particles sintered with a binder — with a hardness around 3,500 HV, the second-hardest cutting tool material commercially available after PCD. Its dominant application is machining hardened steel above roughly 55 HRC — bearing races, automotive crankshafts, hardened dies — work that would rapidly destroy a Solid Carbide (VHM) tool. PCBN is genuinely expensive, running 15–30 times the cost of an equivalent carbide tool, but it can deliver 50–200 times the tool life on hardened steel, which only pays back its premium at real production volume (thousands of parts), not on a one-off job.
Read AIMS's full Cutting Tool Materials Guide → for the full hardness/cost/tool-life comparison across all cutting tool materials
What Is a PCBU? (Person Conducting a Business or Undertaking)
A PCBU is the primary duty-holder under Australia's WHS laws — a deliberately broad legal term covering employers, principal contractors, self-employed people and sole traders alike, not just traditional "employers," who must ensure, so far as reasonably practicable, the health and safety of workers and others affected by the business or undertaking.
The "so far as is reasonably practicable" qualifier is doing real legal work here: it doesn't demand the impossible, but it does require a PCBU to actively weigh up the likelihood and severity of harm against the cost and availability of ways to eliminate or minimise it — not simply avoid known hazards after the fact. Because the definition is about the business activity rather than the entity type, more than one PCBU can share duties over the same workplace at once (a site principal contractor and a subcontractor, for example), each independently responsible. Not to be confused with CBU (Completely Built-Up, an equipment-import term) — a similar-looking acronym with no other connection.
Read AIMS's full WHS Laws in Australia Guide →
What Is PCD (Polycrystalline Diamond)?
PCD (Polycrystalline Diamond) is the hardest cutting tool material commercially available — synthetic diamond particles sintered with a cobalt binder, reaching 8,000–10,000 HV — reserved for non-ferrous materials at extreme cutting speed: aluminium engine blocks, copper alloys, and composites such as CFRP, GFRP and graphite. PCD has one absolute, non-negotiable limitation: above roughly 600°C, the carbon in the diamond itself reacts chemically with iron and the tool tip dissolves — which is exactly why PCD must never be used on ferrous (iron-containing) metals, however tempting its extreme hardness might otherwise look on a spec sheet.
Worth keeping distinct from the unrelated PCD (Pitch Circle Diameter) entry in Belts & Drives — same three letters, a completely different meaning (a pulley/sprocket sizing dimension, not a cutting tool material).
Read AIMS's full Cutting Tool Materials Guide → for material selection by workpiece type
What Is PCD? (Pitch Circle Diameter)
In a pulley or sprocket drive, PCD stands for pitch circle diameter — the effective diameter a belt or chain actually rides on, measured through the component's working centreline, not the diameter of its outer edge (OD, outside diameter).
This distinction genuinely matters for calculating drive speed ratios correctly: driven shaft speed equals driver shaft speed multiplied by driver PCD divided by driven PCD. For example, a 1,450 RPM motor with a 100 mm driver PCD driving a 200 mm driven PCD sheave gives 1,450 × (100/200) = 725 RPM — using outside diameter instead of PCD in that calculation (a common and genuine sizing error) throws the result off, since PCD on an SPB sheave runs roughly 8 mm smaller than OD. These same three letters cover two other, completely unrelated meanings worth disambiguating: in cutting tools, PCD (Polycrystalline Diamond) is a cutting-tool material, not a dimension at all; and in an automotive context, PCD almost always means wheel bolt pattern circle diameter (the circle traced through a wheel's stud or bolt holes, e.g. "5x114.3 PCD") — a genuinely different measurement on a genuinely different component, and the highest-volume everyday use of the term. All three are legitimate, and which one applies depends entirely on context — a drive sheave/sprocket, a cutting tool spec sheet, or a road wheel.
Read AIMS's full Pulley Types Guide →
Shop AIMS's range of pulleys & sheaves →
What Is Penetrating Oil?
Penetrating oil is a low-viscosity fluid designed to wick into the tight gaps between corroded, seized or rusted threaded fasteners and joints, freeing them rather than providing ongoing lubrication. AIMS's own guide breaks down how it actually works: a solvent component dissolves rust and mineral deposits, a surfactant component lowers surface tension so the fluid can capillary-action its way into micro-gaps, and a carrier oil suspends the solvent and provides temporary lubrication once the joint frees up.
The most common mistake, per AIMS's own guide, isn't product choice but technique: trying to turn a seized fastener within 30 seconds of applying penetrant instead of giving it the 15–20 minutes (or 2–4 hours for heavy rust) capillary action actually needs to work. It's also worth knowing WD-40® is "primarily a water-displacement fluid and light penetrating oil" rather than a true dedicated penetrant — for genuinely seized fasteners, a purpose-built penetrant outperforms it.
Read AIMS's full Penetrating Oil Guide: Types, Uses & Australian Brands →
Shop AIMS's range of penetrating and other lubricants →
What Is Phenolic Resin Bond (Cutting Disc)?
Phenolic resin is the resin binder most cutting and grinding discs use to hold their abrasive grain and Fibreglass Reinforcement Mesh together, chosen for its heat resistance and mechanical toughness under the high-speed, high-friction loads of cutting and grinding. It's one of the two resinoid options covered under Bond Type above, specific to the thin, reinforced discs used on angle grinders and cut-off saws rather than bench-grinder wheels.
What Is a Phillips Head (Cross-Head Screw Drive)?
A Phillips head is a cross-shaped ("+") internal screw drive recess, distinct from the flat-bladed slotted drive it was designed to replace — engineered with a deliberately self-centring, slightly rounded recess that helps a power screwdriver find its position quickly during assembly.
Phillips and its close relative Pozidriv are both intentionally designed to cam out (the driver bit slips out of the recess) once a set torque threshold is reached, which limits maximum achievable torque but also protects against over-tightening — the trade-off against Torx and square (Robertson) drives, which resist cam-out and allow much higher torque but give the operator less built-in protection against over-driving a smaller fastener. AIMS's own guide covers Phillips alongside the other common drive types used across Australian industrial supply.
Read AIMS's full Screw Head Types Guide → for the complete drive-type comparison
Shop AIMS's range of screwdrivers & nut drivers →
What Are Pig Trailer / Dog Trailer?
A pig trailer (also called a dog trailer) is a full trailer with its own front steering axle group, connected to the towing vehicle or lead trailer by a rigid Drawbar rather than resting its front weight on a Fifth Wheel Coupling the way a semi-trailer does. Because it steers and tracks independently rather than being carried, it behaves differently in reversing, tight yards and tight turns — a distinction worth knowing before assuming "trailer" always means semi-trailer.
What Is a Pillow Block (Plummer Block)?
A pillow block is a pre-assembled bearing unit: an insert bearing — typically a spherical-outer-ring Deep Groove Ball Bearing or Spherical Roller Bearing — mounted in a one-piece cast iron or pressed steel housing with a flat base and two bolt holes, designed to sit on a horizontal surface. It's tolerant of a genuine amount of shaft and mounting misalignment by design, which is exactly why it's the default choice for shafting bolted to a structure that isn't machined to bearing-fit tolerances.
A plummer block is the closely related split-housing version — a base and a separate cap joined by bolts, rather than one solid casting — used with larger shafts (commonly above 60–80 mm) and adapter-sleeve-mounted spherical roller bearings. "Pillow block" is the standard Australian and US term for the solid one-piece housing; "plummer block" is the UK and European term, sometimes used generically in Australian trade for either, though the engineering designations (solid UCP-series versus split SN/SNH/SD-series) distinguish them clearly.
Read AIMS's full Pillow Block Bearing Guide: UCP, UCF, UCFL & Plummer →
Shop AIMS's range of bearing housings →
What Is a Pilot Bore? (Pulley Mounting)
A pilot bore pulley is supplied with a small standard bore that gets machined out on-site to the exact final shaft diameter, rather than being fitted with a Taper Lock Bush off the shelf.
It's the right choice for non-standard shaft sizes, prototype or one-off work, or any site that has a lathe and needs a bore size outside the standard taper-lock range — the trade-off against taper lock or a bored-and-keyed pulley is the extra machining step, but it removes any constraint on the final bore diameter.
Read AIMS's full Pulley Types Guide →
Shop AIMS's range of pulleys & sheaves →
What Is Pipe Dope?
Pipe dope (traditional jointing compound) is a paste-form pipe-thread sealant, applied to male threads before assembly. It doesn't cure to a hard bond, so under pressure or vibration it can squeeze or wash out of the joint and into the system — a serious contamination risk in hydraulic fluid, and a real concern in any application with filters, valves or precision equipment downstream.
See Thread Sealant and PTFE (Thread Sealing) for how it compares with anaerobic liquid thread sealant and PTFE tape, the other two common ways to seal a threaded pipe joint.
What Is a Piston Compressor? (Reciprocating Air Compressor)
A piston compressor uses a crankshaft-driven piston moving inside a cylinder to draw in and compress air, exactly like a car engine running in reverse — single-stage units compress in one pass, while two-stage units compress, cool, then compress again for higher pressure and better efficiency. Most fixed workshop units are belt-driven rather than direct-drive: a lower pump speed means less heat, less wear, a quieter compressor and a longer service life, which is why belt drive is the near-universal recommendation for a permanent installation.
Piston compressors suit intermittent workshop use rather than sustained demand — typical Duty Cycle (Air Compressor) ratings run 25–75%, they're noisier than the alternative (75–95 dB(A)), and they cycle on and off against a pressure switch (see Cut-In / Cut-Out Pressure). Above roughly 15 L/s of continuous air demand — spray painting, sandblasting, multiple simultaneous tools — a Rotary Screw Compressor becomes the more cost-effective and reliable choice, since it's built for 100% continuous running rather than cycling.
Read AIMS's full Air Compressor Guide → for belt vs direct drive and single- vs two-stage detail
Shop AIMS's range of air compressors & pneumatic equipment →
What Is Pitch Diameter?
Pitch diameter is the imaginary diameter that passes through a thread at the point where the thread groove width and the thread width are equal — a theoretical reference diameter, midway between major and minor diameter, that's actually used to define and gauge thread fit rather than either extreme dimension.
Pitch diameter is the dimension thread gauges (Go/No-Go gauges) actually check, because it's the single figure most directly linked to how a fastener will fit and function once assembled — two threads with identical major and minor diameters can still fit completely differently if their pitch diameters differ. This is one of several thread-related terms worth cross-referencing together with Major Diameter, Minor Diameter and Thread Fit. *(General engineering fundamentals — no dedicated AIMS article specifically on pitch diameter, though it underlies AIMS's Thread Gauge Guide.)*
Shop AIMS's range of thread gauges →
What Is PIW Rating? (Pounds per Inch of Width)
PIW — pounds per inch of width — is the imperial belt-strength rating still seen on US-manufactured conveyor and drive belting: the full-width breaking (tensile) strength of the belt's Carcass (Conveyor Belt), expressed in pounds-force per inch of belt width. A "600 PIW" belt, for example, is rated to withstand roughly 600 lb of pulling force for every inch of its width before the carcass fails.
Australian and other metric markets rate belting the same way but in kN/m or N/mm instead — most commonly seen as the EP rating printed on fabric-ply belting (e.g. "EP400/3": 400 N/mm rated strength across 3 plies of polyester-nylon fabric). The two scales convert directly, since both are simply force per unit width: 1 PIW ≈ 0.175 kN/m (0.175 N/mm), so a 600 PIW belt equates to roughly 105 kN/m. It's a straightforward unit conversion of the same underlying measurement rather than a different rating basis, but it's still worth checking which scale a supplier's datasheet is actually quoting before comparing two belts on strength — an imported or legacy PIW spec sitting next to a metric one is an easy way to misjudge a belt's real capacity.
What Is a Plain Bushing (Plain Bearing)?
A plain bushing — or plain bearing — is a sliding-contact bearing: a simple cylindrical sleeve with no Rolling Elements at all, relying on a low-friction bearing material (bronze, or a polymer such as PTFE-lined composite) running directly against the shaft. It's a cost-effective choice for moderate loads at low speeds, or wherever a rolling-element bearing's cost, size or contamination sensitivity isn't justified.
Read AIMS's full Rolling Bearings: Types, Selection, Fitting & Failure Guide →
Shop AIMS's range of bushings →
What Is a Plate Clamp?
A plate clamp is a below-the-hook lifting device that grips the edge of a steel plate and converts the load's own weight into clamping force via an internal cam — the harder the plate tries to slip, the tighter the jaw bites. Each clamp is rated to a specific Working Load Limit and designed to lift one plate at a time. Vertical clamps grip a single top edge on a plate hanging vertically, suiting sheet-stack handling and vertical transport; horizontal clamps lift plates that stay flat throughout the lift and must always be used in matched pairs to stop the load tipping, suiting concrete sleepers and fabricated panels that need to land level; universal clamps handle both orientations in one unit, trading some top-end capacity for workshop flexibility. AIMS stocks plate clamps from 500 kg (Challenger Universal) up to 5 tonnes (Beaver range), governed by AS 4991 for the below-hook lifting device itself alongside AS 1418.1 & AS 1418.2 for the lifting machine — see both entries above.
Read AIMS's full Plate Clamp Guide → for vertical, horizontal and universal selection
Shop AIMS's range of plate clamps →
What Is Plating (General)?
Plating is the general term covering any process that deposits a thin metallic coating onto a part's surface — Electroplating (electrical deposition), Hot Dip Galvanizing (molten metal immersion) and Sherardizing (diffusion coating) are the three specific plating processes covered as their own entries in this glossary, each producing a different coating thickness, corrosion life and thread-fit outcome from the same basic goal of protecting the base metal underneath.
Read AIMS's full Zinc Plated vs Galvanised vs Stainless: Bolt Coatings Guide →
What Is PM-HSS / HSSE (Powdered-Metallurgy High-Speed Steel)?
PM-HSS (Powdered-Metallurgy High-Speed Steel) is produced by sintering HSS from powder rather than casting it conventionally, which produces a finer, more uniform grain structure than cast HSS — and a finer grain means both a sharper cutting edge and better toughness at the same time, rather than trading one for the other the way most material choices do. AIMS's range covers a V3 grade (optimised for the sharpest edge and the smoothest surface finish, suited to finishing applications) and a Co (cobalt) variant (adding thermal stability specifically for tapping alloy and superalloy materials), with a further premium SPM (Special Powder Metallurgy, 11% cobalt) grade — around 1,050 HV — sitting as a genuine bridge between the HSS family and Solid Carbide (VHM), the hardest material in the HSS lineage while still retaining real toughness. HSSE is the trade name commonly used for a premium, vanadium-alloyed conventional (non-powdered) HSS grade that sits just below PM-HSS in the same premium tier.
Read AIMS's full Cutting Tool Materials Guide → for the complete material hierarchy from HSS through to PCD
What Is a Polychain Belt? (Poly Chain GT Synchronous Belt)
A Polychain belt (Gates Poly Chain GT) is a high-power Synchronous (Timing) Belt built with a carbon-fibre tensile cord and a polyurethane tooth body, designed specifically to replace roller chain on heavy industrial drives rather than to serve as an upgrade to a standard rubber timing belt. The carbon-fibre cord is significantly stiffer per unit cross-section than a standard timing belt's fibreglass or aramid cord, letting it carry chain-level loads at a fraction of the weight, with no lubrication, no stretch and none of chain's noise or maintenance.
Because it's a toothed, synchronous design, a Polychain drive engages positively rather than relying on friction, so it doesn't slip or lose position the way a V-Belt (Drive Belt) can under shock load. Critically, Polychain GT pulleys are not interchangeable with standard HTD or curvilinear timing pulleys, even at the same tooth pitch — a Polychain belt needs a matching Polychain GT sprocket, not a general-purpose timing pulley. AIMS stocks the Gates Poly Chain GT Carbon range in 5MGT, 8MGT and 14MGT pitches, specced for conveyors, crushers, pumps, fans and mining equipment wherever a Roller Chain Drive's noise, lubrication needs or maintenance load is the problem being solved.
Read AIMS's full Synchronous Timing Belt Guide →
Shop AIMS's range of Polychain GT Carbon belts →
What Is Polyethylene Pneumatic Tubing? (PE Tube)
Polyethylene (PE) tube is the lowest-cost pneumatic tubing option — moderately flexible but noticeably stiffer than PU Pneumatic Tubing, and rated to a lower working pressure of around 6–8 bar with a –20°C to +60°C temperature range. Chemical resistance is reasonable for water and mild fluids, and HDPE variants hold up to UV reasonably well, but it doesn't match nylon or PU's all-round performance.
Its place is low-cost instrumentation and signal or pilot lines rather than a main pneumatic circuit or continuous tool supply — where PU Pneumatic Tubing or Nylon Pneumatic Tubing is the correct call. It's a genuine option to reach for when the run is non-critical and price is the deciding factor, not a substitute where working pressure or continuous flow is actually demanding.
Read AIMS's full Pneumatic Fittings & Air Line Components Guide → for full material specifications
What Is Polyurea Grease?
Polyurea grease is a high-temperature thickener chemistry, rated to around 180°C, commonly specified for electric motor bearings, ovens and conveyor bearings running hot. The critical practical warning, repeated throughout AIMS's own material: polyurea must never be mixed with lithium-based greases during relubrication — the two thickener chemistries are largely incompatible, and mixing them breaks down the grease's structure rather than simply diluting it (see Grease Compatibility), which is exactly the kind of mistake that turns a routine regrease into a bearing failure.
Shop AIMS's range of greases →
What Is PPE? (Personal Protective Equipment)
PPE stands for personal protective equipment — any equipment worn or used by a worker to minimise exposure to a workplace hazard, from safety glasses and gloves through to respirators, hearing protection and fall-arrest harnesses.
Under Australian WHS law, PPE sits at the bottom of the Hierarchy of Controls — it's the last line of defence, used to protect the individual once the hazard itself couldn't be eliminated, substituted or engineered out. That doesn't make it optional; it means PPE selection should always follow a genuine risk assessment, not replace one.
Shop AIMS's range of safety equipment & PPE →
What Is a Pre-Bulbed Rivet?
A pre-bulbed rivet is a structural blind rivet that begins forming its locking bulge earlier in the pulling stroke than a standard bulb-type rivet, giving a shorter, more controlled set and — in confined-access joints — a more predictable, repeatable clamp result.
This is a refinement within the same Bulb rivet family (branded examples again include Gesipa® BULB-TITE® variants), aimed at applications where grip range or access is tight enough that a standard bulb rivet's setting behaviour becomes less predictable. *(General fastening-industry terminology, within the structural blind rivet family AIMS's own rivets guide covers.)*
What Is a Predator Belt? (Aramid-Cord V-Belt)
A Predator belt is Gates's heavy-duty V-Belt (Drive Belt), built around an Aramid (Kevlar®) tensile cord in place of the polyester cord used in a standard V-belt, giving it significantly higher tensile strength and fatigue resistance under shock loading and overload — the aramid cord handles sudden starts, stops and torque spikes that would crack a conventional belt's cord, while the bareback cover resists slippage and puncture in dirty, oily or abrasive conditions.
The practical payoff is power capacity: a Predator belt can carry up to roughly 2.2 times more power than a standard belt of the same section, so a drive can often run on fewer belts (or a smaller section) for the same load, without any change to the pulleys — it runs on the same standard SPZ/SPA/SPB/SPC and 3VX/5VX/8VX sheaves as any other narrow or classical V-belt. AIMS stocks it in single-belt and banded configurations, and it's specced wherever routine V-belts fail prematurely: mining and quarrying, wood processing, agricultural machinery and heavy industrial drives with regular shock loading or overload. For a drive running comfortably within its rated load, a standard V-belt remains the more cost-effective choice — the Predator's premium is earned in genuinely harsh-duty applications, not routine service.
Shop AIMS's range of single Predator belts and banded Predator belts →
What Is Preload?
Preload is the initial tension deliberately built into a bolt when it's tightened, before any external service load is ever applied — it's the "F" in the T = K × F × d torque formula, and it's what actually keeps a joint clamped together in service.
A correctly preloaded joint behaves quite differently from an under-tightened one: as long as external service load stays below the preload the bolt already carries, the clamped joint doesn't separate and the bolt sees very little additional stress cycling — which is a major reason correctly preloaded bolted joints resist fatigue far better than people intuitively expect. Preload is limited from above by Proof Load (tightening past it risks permanent bolt stretch) and is what a torque wrench, angle-controlled method or DTI washer are all, in different ways, trying to achieve and verify.
Read AIMS's full Metric Bolt Torque Chart → for how torque, K-factor and preload relate
What Is a Pressure Relief Valve?
A pressure relief valve automatically opens once system pressure exceeds a pre-set threshold, venting fluid or gas to protect equipment, pipework or a pressure vessel from a dangerous overpressure event, then re-seats once pressure drops back to a safe level.
In Australia, relief valve set-pressure requirements typically sit alongside AS 4041 (pressure piping) for pipework and AS 1210 (pressure vessels) for tanks and vessels, with AS 1271 covering safety valve certification specifically — getting the set pressure and the valve's own certification right isn't optional paperwork, since an incorrectly-set or uncertified relief valve is a genuine safety failure point rather than just a compliance technicality. Relief valves are distinct from a Check Valve in function even though both can be thought of as "automatic" valves: a check valve prevents reverse flow, while a relief valve protects against overpressure in the forward direction, and a system can genuinely need both for different reasons on the same line.
Shop AIMS's range of relief valves (AS 1271 & AS 1210) →
Read AIMS's full Pressure Relief Valve Guide: Types, AU Standard & Testing →
What Is Prevailing Torque?
Prevailing torque is the torque required to keep turning a fastener *after* it's already fully seated — the resistance created by a locking feature (a nylon insert, a deformed thread, a serrated flange face) rather than by the joint clamping down further.
It's the mechanism behind how a Nyloc® (Nylon Insert Lock Nut) or similar prevailing-torque lock nut resists vibration loosening: the nylon insert grips the bolt threads with continuous resistance all the way to full seating and beyond, rather than relying on friction generated only by clamp force. AIMS's own nut guide notes that this locking effectiveness diminishes with each reuse cycle as the nylon insert wears — a prevailing-torque lock nut is generally a limited-reuse item, not a permanent one. *(General engineering fundamentals, cross-referenced against AIMS's types-of-nuts guide — no single dedicated AIMS article on the prevailing-torque concept itself.)*
What Is a Prime Mover?
A prime mover is the towing unit — a heavy truck tractor — that supplies the engine power and the Fifth Wheel Coupling for a semi-trailer combination, but doesn't itself carry freight; everything it hauls sits on the trailer(s) behind it. Its own mass rating (GVM) and the combination's total rating (GCM) are two separate figures, since the prime mover has to be rated both on its own and as part of whatever it's coupled to.
What Is Proof Load?
Proof load is the maximum tensile load a fastener is specified to withstand without any measurable permanent (plastic) deformation — the practical strength limit a bolt should never be tightened past, sitting just below its actual yield strength as a safety margin.
Proof load is why bolt grade matters so directly for tightening: a Grade 8.8 bolt yields at roughly 80% of its ultimate tensile strength, while a Grade 10.9 bolt yields at around 90% — meaning the higher-grade bolt has proportionally less margin between "correctly tightened" and "permanently stretched," and less visible warning before failure. This is also the underlying reason a Nut must always be rated to at least the same proof load as the bolt it's paired with, as AIMS's own nut guide notes.
Read AIMS's full Bolt Grade Chart → for the full yield-to-tensile ratio table by grade
What Is Property Class?
Property class is the metric fastener grading system (4.6, 5.8, 8.8, 10.9, 12.9) stamped on a bolt head or screw, where the first number × 100 gives the minimum tensile strength in MPa and the second number ÷ 10, multiplied by the first, gives the minimum yield strength — so an 8.8 bolt is 800 MPa tensile, 640 MPa yield.
This is the metric equivalent of the imperial SAE grading system (Grade 2, 5, 8) marked instead with radial lines on the bolt head — the number of lines equals the SAE grade minus two, so three lines mark a Grade 5 bolt. Property class is governed by ISO 898-1 — Mechanical Properties of Fasteners internationally and AS/NZS 4291.1 in Australia, and AS 4100 sets Grade 8.8 as the minimum for structural steel connections.
Read AIMS's full Bolt Grade Chart → for the complete metric-to-imperial property class comparison table
Shop AIMS's range of fasteners →
What Is a Pry Bar?
A pry bar is a flat or shaped steel bar used purely for leverage — separating two mated parts, lifting a component slightly to get a fitting started, or aligning two holes before a bolt goes through — distinct from a wrecking bar (crow bar), which is built and rated for heavier demolition work.
A pry bar's flattened, often angled or forked tip is designed to slide into a narrow gap and lever apart or lift with precision, where a wrecking bar's bulkier profile and greater leverage suit tearing something apart rather than gently separating it.
Shop AIMS's range of prying tools, pry bars & pullers →
What Is PTFE (Teflon) Dry Lubricant Spray?
PTFE spray is an aerosol containing micron-sized polytetrafluoroethylene particles suspended in a solvent carrier; the solvent evaporates after application, leaving a thin, non-tacky, non-staining PTFE film with an extremely low friction coefficient — around 0.04 against steel, among the lowest of any known solid. AIMS's own guide gives its practical temperature range as roughly −40°C to +260°C, and its ideal use case as light, dust-sensitive mechanisms — sliding door tracks, machine tool fences and tables, lock mechanisms, garage door rollers — rather than heavy-loaded gears, conveyor chains or bearings, where the film is too thin to hold up and a proper Grease or Chain Lube is the right choice instead.
"Teflon" is simply the Chemours trademark for PTFE — the chemistry is identical whichever brand name is on the can, and this dry lubricant spray is a genuinely different product from PTFE as a raw material (covered in Measurement & Materials) and PTFE thread-sealing tape (covered in Adhesives & Sealants), even though all three share the same base polymer.
Read AIMS's full Teflon (PTFE) Spray Guide: Uses, Apps & Mistakes →
What Is PTFE? (Thread Sealing)
In an adhesives and sealants context, PTFE most commonly refers to PTFE thread seal tape — a thin film of polytetrafluoroethylene wound around male pipe threads before assembly to fill the thread gap and help prevent leaks.
PTFE tape isn't a single, generic product, either — white tape is for water and low-pressure applications only and is explicitly not permitted on gas connections, while yellow gas tape is denser (roughly 0.1 mm versus white's 0.075 mm), hydrocarbon-resistant and compliant with AS/NZS 5601.1 for natural gas and LPG connections. Correct application is 3–5 turns, wound clockwise, starting one thread back from the tip and wrapped taut. Either colour doesn't bond to the metal and can shred into the system under vibration or repeated assembly — a real concern in any application with filters, valves or precision equipment downstream. See Thread Sealant and Pipe Dope for how it compares with the other two ways to seal a threaded pipe joint, and Teflon (DuPont Brand for PTFE) (Measurement & Materials) for PTFE as a material in its own right.
Read AIMS's full Thread Lock & Seal Guide →
Shop AIMS's range of adhesives, sealants & tapes →
What Is PTO (Power Take-Off)?
A PTO is a mechanism, usually mounted on or driven through the gearbox, that diverts engine power to run auxiliary equipment instead of (or as well as) turning the wheels — a hydraulic pump for a tipper body or crane, a concrete agitator drum, or a compressor, for example. Engaging the PTO is typically only possible with the vehicle stationary and in neutral, since it draws directly off the driveline rather than through a separate power source.
What Is PU? (Polyurethane)
PU stands for polyurethane — an adhesive and sealant chemistry that cures (single-part formulations react with atmospheric moisture, similar in principle to RTV) to a flexible, rubber-like bond that tolerates larger joint gaps than contact adhesive and, unlike standard silicone, can be painted once fully cured.
Fixture time typically runs 1–4 hours with full cure at 24–72 hours. Polyurethane sits alongside MS Polymer (Modified Silicone) as one of two paintable, flexible sealant chemistries used where standard silicone's non-paintable finish is a problem.
Read AIMS's full Industrial Adhesive Types Guide →
What Is PU Pneumatic Tubing? (Polyurethane)
Polyurethane (PU) tube is the default general-purpose tubing for Australian pneumatic circuits — flexible, genuinely kink-resistant, and excellent under abrasion, with 6 mm tube typically rated to 10–12 bar and a working temperature range of –20°C to +60°C. It handles oils and fuels well, and is colour-coded (blue as the standard for compressed air, with black, red and yellow also common) so different circuits can be told apart at a glance across a machine or panel.
Its limits are what push a job toward the alternatives: PU has poor UV resistance, so a run left outdoors in direct sun degrades faster than Nylon Pneumatic Tubing would, and standard PU isn't rated above 60°C — hot compressed air, steam-cleaning environments or fuel-contact lines call for nylon instead. Where cost matters more than performance and the application is a non-critical instrument line rather than a main air circuit, Polyethylene Pneumatic Tubing is the cheaper option. All three connect into a circuit via a Push-to-Connect (One-Touch) Fitting.
Read AIMS's full Pneumatic Fittings & Air Line Components Guide → for the full tubing material comparison table
What Is Pull-Out / Push-Out? (Nutsert Rating)
Pull-out and push-out are the two load ratings published for an installed rivet nut: pull-out is the axial force needed to pull the set nutsert straight back out of its hole; push-out is the axial force needed to push it straight through in the opposite direction. Together they describe how securely the fastener is actually anchored in the panel, independent of the strength of whatever bolt is later threaded into it.
These are distinct from the pull force needed to *set* the nutsert during installation (the force the installation tool itself must generate) — a common point of confusion is treating the installation pull force as if it were the same figure as the installed pull-out rating, when they measure two completely different things at two completely different stages. Where a joint needs guaranteed structural pull-out strength, AIMS's own guide notes that a welded nut generally offers higher pull-out strength than an equivalent rivet nut. *(General fastening-industry terminology, cross-referenced against AIMS's own rivet nut guide.)*
Read AIMS's full Rivet Nut Guide → for installation pull-force figures by thread size
What Is a Pulley?
A pulley is a wheel that a belt runs on to transmit rotational power — used more loosely in everyday trade language for any belt-driven wheel, including flat-faced wheels used with flat belts and Idler Pulley rollers, as distinct from the more precisely V-grooved Sheave.
Every pulley is sized and specified by its PCD (Pitch Circle Diameter), not its outside diameter — see that entry for why the difference matters. See also Taper Lock Bush, Pilot Bore (Pulley Mounting) and Variable Pitch Pulley for how a pulley is actually specified, fitted and adjusted.
Read AIMS's full Pulley Types Guide →
Shop AIMS's range of pulleys & sheaves →
What Is a Purlin Bolt?
A purlin bolt is a bolt-and-nut assembly specifically sized and profiled for fastening steel purlins (the horizontal structural members that support roof and wall cladding) to rafters and girts in Australian steel-frame construction — typically supplied as a matched kit with a flanged or hex bolt and nut, to AS 4600 cold-formed steel structures.
Purlin bolts are a genuine specialty item rather than a generic hex bolt substitute: purlin connections in cold-formed steel framing have their own design rules under AS 4600, and using the correctly rated purlin bolt kit (rather than a generic bolt of similar size) matters for meeting the structural design the connection was engineered to.
Shop AIMS's range of purlin bolts & nuts →
What Is a Push-to-Connect Fitting? (One-Touch Fitting)
A push-to-connect (or one-touch) fitting joins flexible plastic tube into a pneumatic circuit — valves, cylinders, manifolds, FRL units — without threading or gluing. The tube is simply pushed into the fitting body, where an internal stainless steel collet grips the tube's outside diameter and an O-ring forms the seal; pressing the release collar retracts the collet teeth to free the tube again. Unlike a QC or Nitto-Style Coupler, which are built for fast, repeated tool-end disconnection, a push-to-connect fitting is meant to be a semi-permanent joint inside a built circuit.
They come in the usual configurations — straight union, 90° elbow, tee, bulkhead union for panel penetrations, male/female stud for a BSP port, reducer, plug/cap — sized to match standard tube ODs from 4 mm up to 12 mm. The most common installation error is cutting the tube at an angle with a knife or scissors rather than a dedicated pneumatic tube cutter: the tube end has to seat flat against the internal O-ring to seal, and an angled cut leaves a weeping or hissing leak that looks like a fitting fault but isn't. John Guest is a widely used brand built on this collet-and-O-ring mechanism, common in food, brewery and laboratory settings as well as general automation. See PU Pneumatic Tubing for the tube itself.
Read AIMS's full Pneumatic Fittings & Air Line Components Guide → for the full tube-size-to-bore reference table
Shop AIMS's range of hose, ducting & pneumatic fittings →
What Is Putty?
Putty is a soft, workable filler compound pressed into a gap, hole or surface defect by hand and then left to set or cure — used for filling, sealing and minor surface repair rather than for structural bonding between two load-bearing parts.
Unlike a flowable sealant or liquid adhesive, putty holds its shape as soon as it's placed, which makes it useful for irregular or vertical repairs where a runnier product would sag before it cured.
What Are PVD Coatings (TiN / TiAlN / AlCrN / TiCN)?
PVD (Physical Vapour Deposition) coatings are thin, hard ceramic layers applied to a cutting tool's surface, extending tool life 3–10 times over an uncoated equivalent by reducing edge friction, raising surface hardness and improving thermal stability at the cutting edge. AIMS's guide covers four coatings in everyday industrial use, each suited to a distinct job: TiN (Titanium Nitride, gold-yellow, ~2,300 HV, effective to about 600°C) is the entry-level, general-purpose coating for drilling and tapping, but should be avoided on hardened steel above 45 HRC or at very high cutting speeds; TiAlN (Titanium Aluminium Nitride, violet-grey, ~3,300 HV, effective to about 900°C) is the modern standard for solid carbide tooling on stainless, alloy steel and titanium, but reacts chemically with aluminium and wears rapidly on it; AlCrN (Aluminium Chromium Nitride, blue-grey, ~3,200 HV, effective to about 1,100°C) suits hardened steel up to 54 HRC and — unlike TiAlN — is genuinely safe on aluminium and dry machining, since it doesn't share TiAlN's chemical reaction with it; and TiCN (Titanium Carbonitride, blue-grey, ~3,000 HV, effective to about 400°C) is aimed at abrasive materials — grey cast iron, heat-treated and hardened tool steel up to about 50 HRC — but has the lowest thermal ceiling of the four. Picking the wrong coating for the job isn't a minor inefficiency: AIMS's guide puts the cost of a mismatched coating choice at losing 30–80% of the tool's potential working life.
Read AIMS's full Cutting Tool Coatings Guide → for the complete coating comparison and selection guidance
Q
What Is QC? (Quick-Connect / Quick-Coupler)
In pneumatics, QC is trade shorthand for a quick-connect (or quick-coupler) air fitting — a plug-and-socket pair that lets a tool or hose be disconnected from the airline in seconds, without tools and without fully depressurising the line. The socket half carries a spring-loaded locking sleeve and a check valve; pushing the plug in engages a ring of locking balls, and retracting the sleeve releases it. Genuine AIMS stock is built to the Nitto-Style Coupler profile that dominates Australian workshops, though the term "QC" is used loosely across any quick-disconnect air fitting.
Worth flagging so it doesn't cause confusion: QC is a genuine acronym collision. In a manufacturing or procurement context, "QC" almost always means Quality Control — the inspection and process-conformance discipline — a completely unrelated meaning that comes up just as often in everyday trade conversation. On AIMS's site and in trade conversation about airlines and fittings, the quick-connect sense above is what's meant; anyone landing here from a QC-as-Quality-Control search has come to the wrong glossary entry. QC couplers are distinct from a Push-to-Connect (One-Touch) Fitting, which is a permanent join for building a pneumatic circuit rather than a tool-end disconnect point.
Read AIMS's full Pneumatic Fittings & Air Line Components Guide → for coupler compatibility and thread sizing
Shop AIMS's range of pneumatic tools & air line fittings →
What Is a Quarter-Turn Valve?
Quarter-turn valve is the general category name for any valve actuated by a single 90° stem rotation between fully open and fully closed — covering both the Ball Valve and the Butterfly Valve, the two dominant quarter-turn designs in industrial supply.
The defining practical advantage over a multi-turn valve like a Gate Valve or Globe Valve is speed of operation: a quarter-turn valve opens or shuts in one quick motion rather than dozens of handwheel turns, which matters for emergency isolation but is also exactly why quarter-turn valves need deliberate care when used for throttling — see Throttling Valve for why running either type part-open for extended periods isn't necessarily safe without checking its specific throttling rating first.
What Is Quenching? (Tempering & Normalizing)
Quenching is rapid cooling of steel from the Austenite phase (in water, oil or air) to lock in a hard Martensite structure. Tempering is a controlled reheating of that quenched steel to a lower temperature afterward, trading away some hardness for the toughness needed to make the part usable rather than brittle. Normalizing is a similar heat-and-air-cool process aimed at producing a uniform, moderate-strength grain structure rather than maximum hardness.
"Quenched and tempered" is the standard description for most high-tensile bolts and structural fasteners — grade 8.8, 10.9 and 12.9 bolts are all quenched and tempered to reach their rated strength, with the tempering step controlling exactly how hard versus how tough the finished bolt is.
Read AIMS's full Bolt Grade Chart →
What Is a Quick Release Clamp?
A quick release clamp uses a spring-loaded sliding bar and a squeeze-trigger action to clamp or release almost instantly with one hand — trading some of a screw-driven F-Clamp's maximum clamping force for dramatically faster setup and release on repetitive clamping work.
That one-handed speed is exactly why quick release clamps are the standard choice on a job needing many clamps applied and removed quickly — a glue-up with multiple joints, or holding several parts in a jig for a batch of identical operations — where winding a screw-driven clamp open and shut each time would cost real time across a whole job.
Shop AIMS's range of quick release clamps →
R
What Is a Race (Raceway)?
A race, or raceway, is the hardened, precision-ground surface inside a bearing that the Rolling Elements run on. Every rolling-element bearing has two: an inner race fitted to the shaft, and an outer race fitted to the housing, with the rolling elements and Cage running in the gap between them.
In AIMS's catalogue this is the only common use of "race" — worth noting only because the word has an unrelated everyday meaning (motorsport) that a search engine might otherwise assume.
Read AIMS's full Rolling Bearings: Types, Selection, Fitting & Failure Guide →
What Is Radial Load (Bearing)?
Radial load is force applied perpendicular to a bearing's axis — the everyday case of a shaft's own weight, or a belt or gear pushing sideways on it. It's the load direction a Deep Groove Ball Bearing, Cylindrical Roller Bearing or Needle Roller Bearing is primarily built to carry.
"Load" covers several genuinely different meanings across AIMS's catalogue — rigging's Working Load Limit, a bearing's radial or axial load rating, and electrical current draw — so this entry deals only with the bearing sense; see Axial Load / Thrust Load for the load direction perpendicular to this one.
Read AIMS's full Rolling Bearings: Types, Selection, Fitting & Failure Guide →
What Is a Radiant Heater? (Industrial)
An industrial radiant heater emits infrared radiation that heats objects and people directly, rather than heating the air in between — the opposite mechanism to a Forced-Air Convection Heater, which warms the air itself and relies on that warm air staying put.
Because it isn't heating the air, a radiant heater doesn't lose efficiency every time a roller door opens or a forklift drives through — it's the most energy-efficient option for high-ceiling workshops, loading docks and outdoor or semi-outdoor work bays with frequent door traffic. It's a poor match for a sealed, insulated workshop that needs the whole space brought up to temperature evenly, where a convection or forced-air unit does a better job. Industrial radiant heaters are available in both gas/diesel-fired and electric formats, with electric units generally running off a Single-Phase Fan/Heater Supply at lower outputs and Three-Phase Fan/Heater Supply for larger fixed installations.
Read AIMS's full Industrial Heating Guide →
What Is a Radius Gauge (Fillet Gauge)?
A radius gauge (fillet gauge) is a set of thin, stepped steel leaves with concave and convex profiles machined onto their edges, used to check the radius of a fillet, corner or curved edge against a specific measurement without needing a dial instrument or optical comparator. Correct use is a light-blocking check: the correct leaf sits flush against the curve with no visible gap and no rocking, while an incorrect leaf shows daylight at the edges or rocks under light finger pressure. Available in metric and imperial leaf sets, it belongs to the same "go/no-go by feel" family as the Feeler Gauge above, just checking a curved profile rather than a flat gap.
Shop AIMS's range of radius gauges →
What Is a Raw-Edge / Cogged V-Belt?
A raw-edge V-belt has no fabric cover over its rubber body, and is usually also cogged (moulded notches on the underside) — the combination gives better heat dissipation and flexibility around small-diameter pulleys than a Wrapped V-Belt, at the cost of the fabric layer's environmental protection.
Narrow-wedge (SP-profile) belts built this way carry up to three times the power capacity of an equivalent classical wrapped belt, due to the combination of the deeper wedge angle and the more efficient heat dissipation — which is why raw-edge cogged construction dominates modern high-power industrial drives rather than being a niche option.
Read AIMS's full V-Belt Sizing & Identification Guide →
Shop AIMS's range of industrial drive & conveyor belts →
What Is an RCD (Residual Current Device)?
An RCD (Residual Current Device) is an Australian safety switch that monitors the current flowing out through the active conductor against the current returning through the neutral, and trips the circuit the instant it detects a leakage — the situation created by a person or object providing an unintended path to earth. Where a standard Circuit Breaker protects wiring and equipment from overload, an RCD's job is specifically to protect people from electric shock, and AU wiring rules (AS/NZS 3000) require them on most household and workplace circuits.
What Is a Reamer?
A reamer is the tool that turns a drilled hole into a genuinely precision hole — finishing a pre-drilled hole to a tight tolerance (H7 is the default, around ±0.015mm at 10mm diameter) and a smooth surface finish (1.6 µm Ra standard), well beyond what drilling alone can achieve. A reamer is always run after drilling deliberately undersize, never used to remove significant stock on its own — the standard allowance is only 2–3% of the reamer's diameter, working out to roughly 0.1–0.2mm per side under 5mm diameter, up to 0.3–0.4mm per side at 10–20mm. See Chucking Reamer and Bridge Reamer above for the machine-driven and structural-steel variants respectively, and governed in Australia and internationally by DIN 206 (hand reamers), DIN 212 (chucking reamers) and ISO 521.
Read AIMS's full Reamer Guide → for the complete stock-allowance table and standards
Shop AIMS's range of reamers →
What Is Rebar?
Rebar — short for reinforcing bar, and also called reinforcement steel or, in Australian trade slang, "reo" — is a steel bar with a ribbed, deformed surface pattern embedded in concrete to carry the tensile loads plain concrete is weak against, since concrete on its own resists compression well but cracks and fails under tension or bending.
Australian rebar is sized and graded under AS/NZS 4671, with bar designations like N12, N16, N20 and N24 giving the nominal diameter in millimetres (N12 = 12 mm) and the "N" denoting normal-ductility deformed bar at 500 MPa minimum yield strength (grade 500N), the standard grade for most structural work. Rebar is placed and tied into its final position before Formwork is closed up and structural Grout or concrete is poured around it — concrete cover thickness over the rebar (not the bar itself) is what actually protects it from corrosion over the life of the structure.
What Is a Receiver Tank?
A receiver tank is the storage vessel that sits between the compressor and the distribution line, buffering compressed air so the motor doesn't have to start and stop every time a tool draws air. It smooths out pressure fluctuation, reduces how often the compressor cycles under intermittent demand, and lets a system absorb a brief high-flow burst — an impact wrench firing, a nailer cycling — beyond what the compressor's steady output alone could supply in that instant.
The common misconception is that a bigger tank means more air: it doesn't. Tank size has no effect on FAD — for any tool with genuinely continuous, sustained demand (an HVLP Spray Gun, a sandblaster) it's the compressor's rated FAD that matters, and the tank only smooths short peaks around it. Most fixed workshop receiver tanks sit under 100 litres at 800–1,000 kPa, which in Australia falls below the state pressure-vessel registration thresholds set under AS 3788 — though periodic visual inspection remains good practice regardless.
Read AIMS's full Air Compressor Guide → for tank sizing guidance
What Is Regulator Droop?
Regulator droop — sometimes called creep — is the tendency of a single-stage gas regulator's delivery (outlet) pressure to drift upward as the cylinder empties, even though the regulator's set point hasn't been touched. A welder might dial in 20 CFH at the start of a full cylinder and find it's crept up to 28 CFH by the time the bottle's running low, wasting gas and, in a gas-critical process, potentially disturbing arc and weld quality along the way.
Droop happens because a single-stage regulator drops cylinder pressure to delivery pressure in one mechanical step, and that step's accuracy depends partly on how much pressure it's being asked to drop from — as the cylinder empties and that gap narrows, the regulator's control gets less precise. A Dual-Stage Regulator avoids the problem almost entirely by splitting the pressure drop into two steps, which is exactly why it's specified for long production runs and precision TIG (Welding) work. For general MIG use or shorter jobs, droop is a manageable, well-understood trade-off rather than a fault — but it's worth knowing about before it shows up as unexplained gas flow drift mid-job.
Read AIMS's full Welding Gas Regulator Guide →
What Is a Respirator?
A respirator is any device worn over the nose and mouth (or the whole face) that filters contaminated air before it's breathed in, protecting against dust, fumes, mists and other airborne hazards that a simple Dust Mask alone may not adequately filter.
There are four main types: disposable filtering facepieces (single-use, maximum Respirator Filter Class P2, suited to occasional or one-shift exposure); half-face reusable respirators with replaceable filter cartridges (also maxing out at P2); full-face reusable respirators, which add eye protection and can reach P3; and PAPR, the powered option for workers who can't get a reliable facial seal. Which type and filter class is correct depends on the specific hazard — see AS/NZS 1715 — Respiratory Protection Selection for how that decision is actually made.
Read AIMS's full Respirator & Dust Mask Guide →
Shop AIMS's range of respiratory protection →
What Are the Respirator Filter Classes? (P1/P2/P3)
Respirator filter classes under AS/NZS 1716 rate how effectively a filter removes particles from the air, from P1 (lowest) to P3 (highest) — they're not interchangeable, and the class needed depends entirely on the hazard, not personal preference.
P1 filters at least 80% of mechanically-generated particles and suits nuisance dust and low-hazard cutting. P2 filters at least 94% of both mechanically and thermally generated particles down to fine sizes, and is the workhorse class for silica dust, welding fume and wood dust. P3 filters at least 99.95% of particles and is required for licensed asbestos removal and highly toxic metal dust — critically, P3 can only be achieved with a full facepiece respirator; a half-face mask or disposable respirator cannot be rated P3 no matter what filter is fitted.
Read AIMS's full Respirator & Dust Mask Guide →
Shop AIMS's range of respiratory protection →
What Is a Retaining Compound?
A retaining compound is an Anaerobic Adhesive engineered specifically for cylindrical assemblies — it cures when confined between close-fitting metal surfaces in the absence of air, filling the microscopic voids in the interface to lock a bearing, bushing or hub onto its shaft or into its housing bore, and to prevent fretting corrosion and bearing spin.
Grades vary by strength, cure speed and the size of clearance they can take up: Loctite 641 is the industry default for routine bearing installation (20-minute working window, disassembly still possible), 638 is a permanent high-strength option (about 4,500 psi shear, 4-minute fixture), 648 is a rapid-cure high-strength variant that's NSF/ANSI 61 certified for food-grade use, and 660 is formulated specifically for salvaging a worn bore, taking up clearances as large as 0.50 mm. Measuring the actual fit and confirming the diametral clearance sits within the chosen grade's limit is the critical step before specifying any of them.
Read AIMS's full Loctite Retaining Compound Guide →
Shop AIMS's range of Loctite retaining compounds →
What Is a Retaining Ring?
A retaining ring (also called a circlip or snap ring) is a semi-flexible metal ring that seats into a machined groove on a shaft or inside a bore to stop a bearing, gear or other component from sliding axially along it.
External retaining rings fit around a shaft — expanded open with circlip pliers to pass over the shaft, then released to spring closed into the groove. Internal retaining rings fit inside a bore — compressed with pliers to fit inside, then released to spring open into the groove; these are common in bearing housings, preventing the bearing race from creeping. DIN 471 — Retaining Rings (external) below and DIN 472 (internal) are the metric standards that size both types against the shaft or bore diameter itself, not the groove.
Read AIMS's full Circlip Guide → for internal/external sizing and E-clips
Shop AIMS's range of circlips, snap rings & retaining rings →
What Is a Ring Test?
A ring test is the mandatory pre-use safety check for a bonded abrasive wheel — the wheel is lightly suspended or supported through its bore and tapped with a non-metallic implement. A clear, sustained metallic ring means the wheel is structurally sound; a dull thud means a crack, and the wheel must be discarded immediately rather than fitted. It's a required step before mounting any new Grinding Wheel, not an optional precaution.
What Is a Rising Stem Valve?
A rising stem valve's stem physically lifts up above the bonnet as the valve opens, giving a clear visual indication of open or closed position from a distance — the required configuration for fire protection isolation valves (OS&Y) and most above-ground industrial process installations, as opposed to a Non-Rising Stem Valve, which suits buried or low-headroom service instead.
A specific, genuinely dangerous failure mode applies to both rising and non-rising stem designs: a broken stem can leave the gate dropped into the closed position while the handwheel still turns freely and appears to show "open" — meaning the position indication itself has failed. Testing actual flow after any over-torqued gate valve, rather than trusting the handwheel position, is the only reliable check.
Read AIMS's full Gate Valve Guide →
What Is a Rivet Gun? (Pneumatic Riveter)
A pneumatic rivet gun — a riveter — pulls a mandrel through the body of a blind (pop) rivet to set it, typically handling 3.2–6.4 mm structural rivets in one to two seconds per rivet. It's an intermittent-duty tool, drawing around 3–4 CFM at 90 psi, and heavy-duty models extend to pulling rivnuts (threaded inserts) as well as standard blind rivets, covering sheet-metal fabrication, trailer and canopy work and general production riveting.
The main ongoing maintenance item is the jaws — the internal gripping mechanism that actually pulls the mandrel — which wear out and need routine replacement, typically every 5,000 to 15,000 rivets depending on rivet size and material. Genuine OEM jaws are worth specifying over cheap aftermarket replacements, which wear noticeably faster and start to slip on the mandrel well before that interval is up; keeping a spare set on the shelf avoids downtime mid-job. Like most pneumatic hand tools, it connects to the airline through a QC quick-connect fitting for fast swap-in at a tool station.
Read AIMS's full Rivet Gun Guide → for hand, lever, pneumatic and rivnut tool types
Shop AIMS's range of pop rivet guns & nut riveters →
What Is a Rivnut / Rivet Nut (Threaded Insert)?
A rivnut (rivet nut, nutsert) is a threaded insert installed from one side of a panel, creating a permanent internal thread in sheet metal or tube too thin to tap directly — see Nutsert above for the terminology overlap, and Anvil, Mandrel, Grip Range and Full Hex above for the installation mechanism and body-style options.
AIMS's own guide splits rivet nut installation tools into hand tools (interchangeable mandrels, typically covering M3–M12), pneumatic tools (requiring 6–7 bar and 3–5 CFM shop air, faster and more consistent), and a not-recommended DIY bolt-and-jam-nut method — plus a critical warning that the depth stop on any of these tools must be calibrated against scrap material first, since an incorrectly set stop is the single most common cause of a rivet nut that spins uselessly once a screw is threaded into it.
Read AIMS's full Rivet Nut Guide → for complete sizing, tools and installation steps
Shop AIMS's range of rivet nuts & nutserts →
What Is a Road Train?
A road train is a Prime Mover towing two or more full trailers in a single combination, most commonly seen on approved routes across regional and outback Australia where traffic density and road geometry allow the extra length safely. Longer combinations link additional trailers using a Converter Dolly or a Turntable, and operating one requires specific route approval, permits and, often, additional driver accreditation beyond a standard heavy combination licence.
What Is Rockwell Hardness (HRB / HRC)?
Rockwell hardness measures the *depth* of indentation remaining after the test load is released and the indenter rebounds slightly — a faster method than Brinell or Vickers, and the standard shop-floor scale for finished steel parts and fasteners. HRC uses a 120° diamond cone indenter under 150 kgf total load, and suits hardened steels — tool steel, hardened structural components, bolts Grade 8.8 and up, bearings. HRB uses a 1/16" steel ball under 100 kgf total load, and suits softer materials — mild steel, copper alloys, brass, aluminium alloys, malleable iron. Both are tested in Australia under AS 1815 (aligned to ISO 6508-3 and ASTM E18), and fastener hardness ranges are additionally governed by AS 4291.1 (aligned to ISO 898-1) — a genuinely practical check on the shop floor: a Grade 8.8 bolt should read 22–32 HRC, and a reading outside that band is a real warning sign of the wrong grade or a counterfeit fastener, not just an academic curiosity.
Read AIMS's full Hardness Testing Guide → for the complete indenter, load and standards table, and Portable Hardness Testers guide → for field-testing options
What Is RoHS? (Restriction of Hazardous Substances)
RoHS is the EU directive restricting the use of specific hazardous substances — lead, mercury, cadmium, hexavalent chromium, and several brominated flame retardants and phthalates — in electrical and electronic equipment sold into the European market, aimed at reducing the environmental and health impact of e-waste.
Australia has no equivalent domestic legislation, but RoHS compliance shows up constantly in AU industrial supply anyway, because so much electrical and electronic componentry — connectors, cable glands, terminals, sensors — is manufactured to a single global specification built around the EU's requirements rather than a separate Australian-only formulation. A "RoHS compliant" callout on an electrical component's datasheet is a materials-restriction claim, not a safety-in-use standard, so it sits alongside rather than replacing AU-specific electrical compliance requirements.
What Is a Roll Groove Fitting?
A roll groove fitting is a pipe-joining method — commonly associated with Victaulic-style couplings — where a groove is mechanically rolled into the pipe end and a two-piece coupling clamps over it, sealing with an internal gasket rather than a weld, thread or flange.
The genuine practical advantage is installation speed and permit status: roll groove joining doesn't require welding or flanging, and critically doesn't require a hot-work permit, which matters on sites where hot work triggers a fire-watch and additional sign-off. It's also disassembled just as fast as it's installed, making it a common choice for systems that need to be reconfigured or serviced repeatedly, such as Butterfly Valve installations in fire protection piping.
Shop AIMS's range of pipe fittings →
What Is a Rolled Thread?
A rolled thread is formed by pressing hardened dies against a rod or bolt blank under high pressure, displacing (not removing) material to form the thread profile without cutting any away — as opposed to a Cut Thread, which removes material with a cutting tool.
Rolling is the dominant commercial-manufacturing method for standard bolts and screws because it's faster, produces less waste, and — critically — leaves the material's grain flow following the thread contour rather than being cut across it, which measurably improves fatigue strength and, to a degree, tensile strength compared with an equivalent cut thread. *(General manufacturing-process fundamentals — no dedicated AIMS article, since AIMS's own Tap & Die Guide covers the cutting method rather than rolling, which is a mill-floor forming process rather than a hand-tool operation.)*
What Is Roller Chain Anatomy? (Pin, Bushing, Roller, Link Plate)
Every roller chain link is built from the same four core components: inner and outer link plates carrying the tensile load, a pin passing through the outer plates as the pivot point where elongation occurs during wear, a bush providing the bearing surface between pin and roller, and the roller itself, which engages the sprocket teeth.
Despite looking superficially similar to a bicycle chain, industrial roller chain is a materially different, heavier-duty product built to the ANSI or ISO/BS pitch and load standards covered under ANSI Roller Chain Numbering and ISO/BS Roller Chain Numbering — the pitch (centre-to-centre distance between adjacent pins) is the single most important dimension for chain-to-sprocket compatibility, more important than any other single measurement on the chain.
Read AIMS's full Roller Chain Guide →
Shop AIMS's range of chain & sprockets →
What Is a Roller Chain Drive?
A roller chain drive is a positive-engagement power transmission system using a chain of pinned links and rollers running over toothed sprockets, giving it the highest torque capacity and shock tolerance of the three main drive types, at the cost of needing ongoing lubrication.
Roller chain runs at up to roughly 15 m/s before lubrication breakdown becomes the limiting factor — well below a V-belt's ~30 m/s or a synchronous belt's ~60 m/s — and its efficiency ranges from 96–98% when properly lubricated down to around 90% when poorly maintained, since lubrication failure is the leading cause of premature chain wear. It's the right choice over a belt for heavy-duty, shock-loaded or harsh-environment drives (crushers, mills, conveyors) where a belt's slip-under-shock behaviour would actually be a liability rather than a protection. See Roller Chain Anatomy, Simplex Roller Chain (and its Duplex Roller Chain / Triplex Roller Chain multi-strand variants) and ANSI Roller Chain Numbering / ISO/BS Roller Chain Numbering for how a specific chain is then specified.
Read AIMS's full Roller Chain Guide and Belt vs Chain Drives Guide →
Shop AIMS's range of chain & sprockets →
What Is a Rolling Element (Ball / Roller)?
The rolling element is the ball or roller inside a bearing that carries the load between the inner and outer Race, replacing the sliding friction of a Plain Bushing with rolling friction, which is lower and generates less heat at a given load and speed.
The rolling element's shape drives the bearing's load character: a ball bearing's point contact handles moderate combined loads efficiently at higher speeds, while a roller bearing's line contact — cylindrical, tapered, spherical or needle — spreads load over a larger contact area and so handles heavier loads, generally at the cost of some top-end speed.
Read AIMS's full Rolling Bearings: Types, Selection, Fitting & Failure Guide →
What Is a Rotary Screw Compressor?
A rotary screw compressor uses two meshing helical rotors that trap and progressively compress air as they turn, producing a smooth, continuous flow rather than the pulsed output of a Piston Compressor (Reciprocating). Most industrial units are oil-injected (the oil seals the rotor clearances and carries away heat) though oil-free designs exist for air-quality-sensitive applications; they're driven directly or through a gearbox rather than by belt.
The defining advantage is duty cycle: a rotary screw compressor is rated for 100% continuous running, against the 25–75% intermittent rating typical of piston units, and it's considerably quieter (62–78 dB(A) versus 75–95 dB(A)). That makes it the right call for production environments, multi-tool workshops with genuinely overlapping simultaneous demand, or any continuous-duty application like spray finishing or sandblasting — generally justified once sustained air demand passes around 15 L/s, below which the piston compressor's lower upfront cost usually wins out. See FAD for how to work out which category your actual demand falls into.
Read AIMS's full Air Compressor Guide → for the full piston vs rotary screw decision framework
Shop AIMS's range of air compressors & pneumatic equipment →
What Are Rotor and Stator?
The stator is the stationary outer part of an electric motor, containing the windings that generate a rotating magnetic field; the rotor is the part that actually turns, driven by that field. In an Induction Motor, the rotor has no direct electrical connection to the stator at all — it's driven purely by electromagnetic induction, which is exactly what allows the brushless, low-maintenance design induction motors are valued for.
What Is a Round Belt?
A round belt is a circular-section drive belt, typically urethane or rubber, used on light-duty drives — packaging machinery, light conveying and similar low-torque applications — rather than the trapezoidal-section V-Belt (Drive Belt) used on standard industrial power transmission drives.
Its round profile lets it run in a V-groove, a round groove, or twisted 90° between non-parallel shafts, giving it more layout flexibility than a V-belt on light-duty equipment — at the cost of a much lower power-transmission capacity, which is why it isn't a substitute for a V-belt or timing belt on any drive carrying meaningful industrial load.
Shop AIMS's range of round belts →
What Is RPM? (Revolutions Per Minute)
RPM (revolutions per minute) is the spindle speed a lathe, drill or mill is actually set to run at — but the figure that determines tool life and surface finish isn't RPM directly, it's surface (cutting) speed: how fast the workpiece's edge is actually moving past the cutting tool, which for a given cutting speed changes with the workpiece's diameter. AIMS's own guide gives the metric formula as N ≈ (Vc × 318) ÷ D (N = spindle RPM, Vc = cutting speed in metres per minute, D = workpiece diameter in millimetres) — as a worked example, turning a 50mm mild steel workpiece in HSS at a 30 m/min cutting speed calls for roughly 191 RPM. The same underlying formula applies to drilling, but with the drill bit's own diameter substituted for the workpiece's outer diameter, since it's the drill's cutting edge — not the workpiece — that's doing the moving in that operation.
Read AIMS's full Lathe RPM Formula Guide → for the complete metric and imperial formulas and worked examples
What Is RTV? (Room Temperature Vulcanising)
RTV stands for Room Temperature Vulcanising — a silicone sealant that cures by reacting with atmospheric moisture at ordinary room temperature, without needing heat, air exclusion or a mixed-in catalyst (see Moisture Cure).
RTV cures to a flexible rubber, letting it absorb vibration and the thermal expansion of dissimilar metals — which is why it's the standard choice for cast engine surfaces, flexible joints and general maintenance sealing, with colour-coded formulations rated from about -54°C up to +371°C depending on grade. It's genuinely different from Anaerobic Gasket Maker in both cure mechanism and finished flexibility — see that entry for the practical comparison, and from Anaerobic Adhesive more broadly for the underlying chemistry family.
Read AIMS's full RTV Silicone & Gasket Maker Guide →
Shop AIMS's range of gasket sealants →
What Is Runout?
Runout is a combined form-and-position error measured relative to a datum axis as a part rotates — distinct from circularity (2D roundness of a single cross-section, no datum required) and cylindricity (circularity plus straightness along the axis, also no datum required), both of which runout folds together with position error in one reading. The common vee-block method mounts a dial indicator on a lathe or between centres; as the part rotates, the maximum reading minus the minimum reading is the TIR (Total Indicated Runout). It's adequate for go/no-go workshop screening, but genuinely conflates several separate sources of error — form error, axial misalignment, vee-block imperfection and centre wear all show up in the same number. Common causes of excessive runout include bearing race defects (a race just 5 microns out of round can produce vibration, premature wear and audible noise), journal wear or grinding error on a crankshaft, and spindle or fixture issues in the setup itself.
Read AIMS's full Roundness Tester Guide → for the full circularity/cylindricity/runout distinction
What Is a Rust Converter?
A rust converter is a chemical treatment — typically tannic-acid or phosphoric-acid based — that reacts with existing iron oxide (rust) to convert it into a stable, paintable compound, rather than removing the rust mechanically first the way a wire wheel or Penetrating Oil and elbow grease would. It's the practical option for rust that's already established on a surface that can't easily be stripped back to bare metal — structural steel, machinery frames, tanks — letting a coating go straight over the converted surface rather than needing full mechanical or chemical rust removal first.
Read AIMS's full Rust Converter Guide → for the full chemistry, honest limits and step-by-step application
Shop AIMS's range of rust treatments and undercoats →
S
What Is S-Cam (Air Brake System)?
The S-cam is the S-shaped camshaft inside a drum-type Air Brake System that converts the Slack Adjuster's rotating motion into an outward push on the brake shoes — as the cam rotates, its S-shaped profile forces the shoes apart against the inside of the brake drum. It's the last mechanical link in the chain from the brake pedal through the Brake Chamber and slack adjuster to the actual friction surface, and a worn S-cam or its bushings is a common cause of uneven brake wear across an axle.
What Is SAE?
SAE stands for the Society of Automotive Engineers — now trading internationally as SAE International — a global engineering standards-development body founded in 1905, publishing close to 10,000 active standards across aerospace (AS and AMS series), automotive and commercial-vehicle (J-series), agricultural, marine and rail equipment. It is not a single standard or a single product spec; it's the organisation behind a very large family of them, so "SAE" alone never fully identifies which standard is meant without more context.
Within AIMS's own product range, two SAE-designated specifications come up most often, and they describe two completely unrelated properties: SAE bolt grades (Grade 2, 5, 8) are the American imperial equivalent of metric property class, covered under Property Class above; SAE viscosity grades (SAE 30, SAE 10W-40) describe oil flow resistance at temperature and have nothing to do with fastener strength. A reader searching "SAE grade" on AIMS's site could plausibly mean either, depending on whether they're looking at fasteners or lubricants — genuinely easy to mix up, and distinct from the wider point that SAE itself covers vastly more ground than just these two.
Read AIMS's full Bolt Grade Chart → for SAE bolt grades specifically
What Is Safety Footwear?
Safety footwear is footwear with a protective toecap and often a puncture-resistant sole, certified in Australia under AS/NZS 2210.3 — the standard requires the toecap to withstand a 200-joule impact and a 15 kN static compressive load, and both steel and composite toecaps must meet that same threshold to be compliant.
The two dominant toecap materials are Steel Cap Boots and Composite Toe Boots, each with a genuinely different trade-off rather than one simply being a lighter version of the other — see those entries for the practical comparison. EH (Electrical Hazard) certification is a separate rating again, confirming a boot provides secondary protection against accidental contact with live circuits up to 600 V AC in dry conditions.
Read AIMS's full Steel Cap Boots Guide →
Shop AIMS's range of safety footwear →
What Are Safety Glasses?
Safety glasses are protective eyewear certified to AS/NZS 1337.1, combining an Impact Class rating for mechanical protection with an Optical Class rating for lens clarity — genuine compliance means both ratings are marked directly on the lens or frame itself, not just the packaging.
Frame style is chosen by hazard: spectacle-style suits light industrial and lab work, wraparound frames add side protection for grinding and woodworking, foam-gasketed frames prevent fine dust bypassing the frame entirely, and OTG (over-the-glasses) styles are a workable but less comfortable option for occasional wear over prescription glasses. Lens tint is a separate choice again — clear for indoor and low-light work, smoke/grey for bright outdoor glare, amber/yellow for contrast in low light (popular for grinding), and mirror tints for extreme glare like roofing or water work. One compliance trap worth knowing: ANSI Z87.1 is the US standard and is not equivalent to AS/NZS 1337.1 — imported glasses marked only with the US standard don't meet Australian workplace requirements.
Read AIMS's full Safety Glasses Guide →
Shop AIMS's range of safety glasses & eye protection →
What Is a Safety Latch (Lifting Hook)?
A safety latch is the spring-loaded (or self-locking) closure across a lifting hook's throat that stops a sling or chain from slipping out under slack or shock-loading conditions. It's considered standard equipment on a rigging hook in Australian practice, and a missing, bent or non-functioning latch is an automatic rejection point on inspection — see Mousing for the manual workaround used where a hook doesn't have a working latch of its own.
What Is a Sanding Belt?
A sanding belt is a continuous loop of coated abrasive, run on a belt sander or linisher for fast stock removal or finishing over a flat or gently contoured surface — the same coated-abrasive principle as Sandpaper, formed into a loop rather than a sheet so the tool can run it continuously rather than lifting and repositioning between passes.
Shop AIMS's range of sanding belts — linishing & portable →
What Is a Sanding Disc?
A sanding disc is a coated abrasive disc — most commonly aluminium oxide (the general-purpose workhorse for wood and mild steel), zirconia alumina (self-sharpening, several times the working life of aluminium oxide on structural steel), ceramic alumina (a premium grain for stainless and hardened tool steel) or silicon carbide (non-ferrous metals, paint and automotive paint feathering) — attached to a random orbital sander, angle grinder (via a Backing Pad), bench disc sander or die grinder depending on its size and backing. Hook-and-loop backing dominates general workshop use for fast grit changes; PSA (adhesive) backing suits single-grit production runs where cost per disc matters more than swap speed.
Read AIMS's full Sanding Disc Guide → for grain selection, backing types and tool compatibility
Shop AIMS's range of self-adhesive discs →
What Is Sandpaper (Base Term)?
Sandpaper is the base term for a coated abrasive — abrasive grain glued to a flexible paper or cloth backing — graded by grit number from very coarse (removing material fast, leaving a rough surface) to very fine (polishing, leaving almost no visible scratch pattern). It's the foundational product underlying the whole coated-abrasive range covered in this category, from loose sheets through to Sanding Belt and Sanding Disc formats built around the same coated-abrasive principle.
Read AIMS's full Sandpaper Grit Guide → for choosing the right grade
Shop AIMS's range of sandpaper sheets — grit 40-2000, wet & dry →
What Is a Scaffold Tag?
A scaffold tag is the coloured tag system attached at a scaffold's access point, under AS/NZS 1576.1, that tells anyone approaching whether it's currently safe to climb — green means it's been inspected by a competent person and found compliant, yellow flags restricted or caution-only use (typically requiring specific PPE or supervisor sign-off), and red means do not access at all, most often because the scaffold is being erected, altered or dismantled.
A green tag is only valid for a maximum of 30 days while the scaffold stays erected, and it has to be re-inspected and re-tagged sooner than that after first use, any structural modification, an incident, or severe weather — many sites layer a daily pre-use visual check on top of that formal inspection cycle rather than relying on the tag date alone. AIMS doesn't stock scaffold tags as a standard line itself, but covers the full tag system — including the equivalent LOTO (lockout/tagout) and test-and-tag colour codes used elsewhere on an industrial site — in its safety tags guide.
Read AIMS's full Safety Tags Guide → for scaffold, LOTO and test-and-tag colour coding under AS/NZS 1576.1
What Is Scotch-Brite® (Non-Woven Abrasive Pad)?
Scotch-Brite® is 3M's trademarked non-woven abrasive pad — synthetic fibres impregnated with abrasive mineral rather than a solid backing or a coated surface — used for light cleaning, blending and finishing without leaving the directional scratch pattern a coated abrasive or Sanding Disc would. It's genuinely become the everyday name for this whole product type, the same way Nyloc® or Dynabolt® has for theirs, even on packs made by other manufacturers.
Read AIMS's full Non-Woven Abrasive Pad & Disc Guide → for grade selection, format choice and stainless-steel handling.
What Is a Scriber?
A scriber is a hardened-point hand tool for marking precise layout lines on metal — a far finer, more accurate line than a pencil or marker can leave, and one that survives handling and machining fluid without wiping off.
Scribing a line before cutting or drilling is standard workshop practice for anything needing accuracy: the line gives a visible reference to cut or drill to, and a Centre Punch mark at the scribed intersection gives the drill a starting point that won't wander off that line.
Read AIMS's full Centre Punch & Scriber Guide →
What Is SDS? (Safety Data Sheet)
An SDS (safety data sheet) is a standardised document a chemical manufacturer or supplier must provide, setting out a substance's hazards, safe handling and storage requirements, first-aid measures and what to do in a spill or fire.
SDS is the current term — it replaced the older name MSDS (material safety data sheet) when Safe Work Australia's model WHS laws harmonised the format nationally, dropping "material" from the title without changing what the document actually covers. The two terms describe the same document, and "MSDS" still turns up often enough in older paperwork and casual trade conversation that it's worth recognising as the same thing rather than something superseded. Every hazardous chemical used, handled or stored at an Australian workplace must have a current SDS readily accessible to workers — it's a legal WHS requirement, not just good practice, and it's the primary reference for filling in the practical detail an SDS alone doesn't cover, like a Spill Kit's contents for a specific chemical class.
What Is a Self-Aligning Ball Bearing?
A self-aligning ball bearing uses a double row of balls running on a spherical outer race, which lets the bearing tolerate genuine shaft-to-housing misalignment — up to around 3°, per AIMS's own guide — without binding or generating extra internal load. That flexibility comes at a cost: for a given bore, it carries less load than an equivalent Deep Groove Ball Bearing, so it's specified where misalignment is the real risk (long shafts, plummer-block mountings, imperfect foundations) rather than as a default choice.
Read AIMS's full Rolling Bearings: Types, Selection, Fitting & Failure Guide →
Shop AIMS's range of self-aligning bearings →
What Is Service Factor? (Belt Drive Selection)
Service factor is a multiplier applied to a belt drive's input power to account for shock loading, duty cycle and starting conditions before a belt profile is selected — producing the corrected Design Power (Belt Drive Selection) figure the actual drive is designed against.
1.5 is a commonly used default service factor when the specific application's factor isn't otherwise specified, though the correct figure varies by load type and duty cycle — a continuously running, lightly loaded fan needs a much lower service factor than a drive with frequent heavy starts or shock loading.
What Is a Shackle?
A shackle is a U-shaped or curved metal connector, closed with a removable pin, used to join a sling, chain or rope to a lifting point or load. AIMS stocks two main body shapes, and the distinction isn't cosmetic — it determines what the shackle is actually rated for: Bow Shackle (Anchor Shackle) — rounded, wider body, rated for multi-leg lifts and side-loaded slinging — and D-Shackle (Chain Shackle) — straight-sided body, rated for in-line pulls only. Never side-load a D-shackle; it isn't rated for it.
Shackles are also graded, and the grade dictates what chain or sling system they're built to pair with: Grade S (standard commercial, blue pin) suits general overhead lifting; Grade T (yellow pin) is built for Grade 80 chain systems; Grade M/Grade 100 (purple pin) is built for Grade 100 chain systems. In Australia, shackles for lifting are manufactured and tested to AS 3776, which sets a 6:1 safety factor, proof-testing at 2× WLL, and mandatory marking of WLL, grade, maker's mark and batch number — so a shackle without that stamped marking shouldn't be trusted for overhead lifting regardless of how it looks.
Every shackle also has a pin type — screw pin (hand-tightened, for temporary or infrequent rigging — and it must be moused with soft seizing wire if the application vibrates or rotates, since a screw pin can back itself out under those conditions) or safety pin (bolt-and-cotter or bolt-and-nut, for permanent or vibration-prone rigging where a screw pin could work loose). Always match the shackle's Working Load Limit (WLL) to the job, stamped in tonnes on the body, and never exceed it — and never side-load a shackle rated for in-line pulls only, which can cut its effective rating by 50% or more.
Read AIMS's full Bow Shackle & D-Shackle Guide → for WLL tables by pin size and grade
Shop AIMS's range of shackles →
What Is a Shaft Collar?
A shaft collar is a ring fitted around a shaft — by set screw, clamp, or as a split two-piece clamp collar — to locate a bearing, gear, pulley or other component axially, or to set the end float of an assembly. A one-piece set-screw collar is the simplest and cheapest option but indents the shaft surface and can loosen under shock load; a split clamp collar grips the full shaft circumference without marking it and holds better under vibration, at a higher cost.
Shop AIMS's range of shaft collars →
What Is a Shaft Seal? (Oil Seal)
A shaft seal — also called an oil seal — is a rotary seal, typically a spring-loaded rubber lip, fitted around a rotating shaft to retain lubricant on one side and exclude dirt, dust and moisture on the other.
Found wherever a shaft passes through a housing wall — pumps, gearboxes, bearing housings and electric motors — a shaft seal is a wear item with a genuinely finite service life, distinct from a static O-ring or a Dowty Washer / Bonded Seal, which seal a fixed joint rather than a moving one. Getting the lip orientation right during fitting matters as much as getting the size right: a seal fitted backwards will pump lubricant out rather than keeping it in.
Shop AIMS's range of oil seals & O-rings →
What Is a Shank?
A shank is the plain, unthreaded (or differently-threaded) body of a fastener between the head and the working end — on a bolt, the section of shaft below the head and above the thread; on a drill bit or rivet, the section gripped by the tool holding it.
In a bolted joint context, shank is effectively synonymous with Grip Length — the unthreaded portion is what should sit across the shear plane in a bearing-type joint. On a self-tapping screw or a specialty fastener, "shank" can also describe a shaped or textured section (see Knurled Shank below) designed to resist rotation once installed rather than to carry shear load. *(General engineering fundamentals — no dedicated AIMS article for this general term.)*
What Is Shear Strength (Single/Double Shear)?
Shear strength is the maximum load a fastener can withstand when the load acts perpendicular to its axis, trying to cut the fastener across its cross-section, rather than pulling it apart along its length (tensile loading).
Single shear describes a joint where the load-carrying planes cross the fastener once (two plates lapped over each other, joined by one bolt or rivet) — the fastener is cut through at one cross-section. Double shear describes a joint where the fastener passes through three plates (or a clevis-and-tang arrangement) so the load-carrying planes cross it twice — a double-shear joint of the same fastener carries roughly twice the load of a single-shear one, since there are two shear planes sharing the load rather than one. Shear strength for a given fastener grade is typically taken as a fraction (commonly around 60%) of its tensile strength, though this varies by standard and material. *(General engineering fundamentals — no dedicated AIMS article for this term, though it underlies AIMS's structural rivet shear ratings.)*
What Is a Sheave?
A sheave is the more precise Australian/UK engineering-drawing term for a V-grooved Pulley specifically — the same physical component, just the term a supplier's technical drawing or specification sheet will use rather than the looser everyday "pulley."
The distinction rarely matters in casual conversation, but it matters when reading a technical drawing or ordering a specific part: engineering documentation will typically say "sheave" for a V-belt or timing-belt groove. Every sheave is sized and specified by its PCD (Pitch Circle Diameter), not its outside diameter — see that entry for why the difference matters. See also V-Belt Profiles (SPZ/SPA/SPB/SPC, Classical A/B/C/D), Taper Lock Bush and Pilot Bore (Pulley Mounting) for how a sheave is actually specified and fitted. This is the power-transmission sense of the word — for the same term used in lifting and rigging (the grooved wheel a wire rope runs around inside a snatch block), see Sheave (Pulley Wheel) in the Lifting & Rigging category.
Read AIMS's full Pulley Types Guide →
Shop AIMS's range of pulleys & sheaves →
What Is a Sheave (Pulley Wheel)?
A sheave is the grooved wheel inside a snatch block or lifting block that a wire rope or cable runs around — "sheave" and "pulley" describe the same component, but sheave is the term you'll see on an AU/UK engineering drawing and on AIMS's own block specifications. It's the same word as the Belts & Drives category's Sheave entry, just a different application: there it's the V-grooved wheel a belt runs on for power transmission; here it's the wheel a wire rope runs around for lifting and load redirection.
Sizing a sheave correctly means matching its diameter and WLL to the wire rope diameter and load, not just to the winch pulling it — AS/NZS 2089 and AS 3569 set a minimum sheave-to-rope diameter (D:d) ratio of 14:1 for infrequent use, 18:1 for general industrial use and 20:1 or more for frequent, production-style service; a smaller sheave than that accelerates wire rope fatigue every time it bends around it.
Read AIMS's full Snatch Block Guide → for the full D:d ratio and block-load tables
Shop AIMS's range of blocks and sheaves →
What Is Sherardizing?
Sherardizing (also called zinc diffusion coating) coats small, intricate parts by tumbling them with zinc powder inside a heated, sealed drum, so the zinc diffuses into the part's surface rather than being electroplated or hot-dip immersed. AIMS's own guide gives a typical coating thickness of 15–40 microns — between standard Electroplating and Hot Dip Galvanizing — and its main practical advantage is even coverage on small, complex-shaped fasteners and fittings that would plate unevenly by other methods.
Read AIMS's full Zinc Plated vs Galvanised vs Stainless: Bolt Coatings Guide →
What Is Shielding Gas?
Shielding gas is the inert or semi-inert gas blanket that protects a weld pool from atmospheric oxygen and nitrogen during MIG (Welding) and TIG (Welding), preventing the porosity, weak welds and oxidation that contaminated welds suffer from. It plays the same protective role that a burning Flux Coating (Stick Electrode) plays in SMAW / MMA — just delivered from a cylinder rather than generated by the electrode itself.
Gas choice is matched to both process and base metal. For MIG on mild steel, a 75%/25% argon/CO₂ blend (commonly called C25) is the de facto Australian workshop standard, with pure CO₂ a cheaper but spatter-prone budget option and a 98%/2% argon/CO₂ mix required for stainless to avoid weld-surface "sugaring." TIG, by contrast, runs almost exclusively on pure argon (99.995% purity) — CO₂ or argon/CO₂ blends will rapidly destroy a Tungsten Electrode Colour Code (AWS A5.12)-rated tungsten and have no place in a TIG cup. Flow rate matters as much as gas type: too low invites contamination, but running noticeably above the recommended 10–15 L/min for MIG (8–12 L/min for standard TIG cups) can actually draw turbulent outside air into the shielding envelope and cause the exact porosity the gas is there to prevent.
Read AIMS's full MIG Welding Guide, TIG Welding Guide and Welding Gas Regulator Guide →
What Are Shims?
A shim is a thin, precisely-thicknessed piece of material — steel, brass, stainless or plastic — inserted between two mating surfaces to take up a gap, correct alignment, or fine-tune a clearance that a standard-sized part can't achieve on its own. AIMS stocks both pre-cut shim stock (sheet or roll, cut to size on site) and pre-formed shim sets or washers in standard thicknesses. Common uses include levelling machinery bases and bearing housings, correcting shaft or coupling alignment, and setting precise valve or gear backlash clearances — see Feeler Gauge above for the tool typically used to measure the gap a shim needs to fill before selecting one.
Shop AIMS's range of shims & shim stocks →
What Is Shoring?
Shoring is a temporary structural support system — most commonly adjustable steel props (often called "Acrow props" after the well-known brand) or purpose-built falsework frames — used to hold Formwork, an excavation wall or an existing structure in place until it can support itself or until permanent support is installed.
It's worth keeping shoring distinct from formwork itself: formwork holds wet concrete in its intended shape, while shoring is the propping and bracing that carries the load formwork and freshly poured concrete impose before the concrete has cured enough to be self-supporting. The same basic principle extends to trench shoring on excavation sites, where the "structure" being supported is the excavation wall itself rather than concrete formwork — a critical WHS control against collapse in deep or unstable trenches.
What Is a Shortening Clutch?
A shortening clutch is a fitting on a multi-leg chain sling that gathers and locks a loop of slack chain within a smooth housing, letting a rigger shorten one leg's effective length on site without swapping the whole sling for a shorter one. It does the same job as a Grab Hook but more smoothly and with a cleaner load path, since the chain isn't bent sharply around a hook's saddle — for that reason a shortening clutch is generally the preferred fitting where fine, repeatable leg-length adjustment matters.
What Is SI (International System of Units)?
SI (Système International d'Unités) is the modern, internationally agreed system of measurement units — the formal standard underlying what's commonly just called "metric." It's built from seven base units (metre, kilogram, second, ampere, kelvin, mole, candela), from which every other unit used in engineering — the newton, pascal, watt, volt and so on — is derived. See Metric above and the Kip / kN / MPa / PSI cluster above for how the everyday force and stress units engineers actually work with all trace back to this base system. *(General engineering fundamentals — no dedicated AIMS article for this term.)*
What Are Side Cutters? (Diagonal Cutters)
Side cutters — also called diagonal cutters or "dikes" in trade slang — are pliers built purely for cutting wire and light-gauge material cleanly and flush, with cutting edges angled diagonally to the jaw rather than the straight-on cutting edge built into general Combination Pliers.
That diagonal edge geometry is what gives a genuinely flush cut close to a surface — trimming a cable tie or a component lead right at the base — which a combination pliers' straight cutting edge can't match. They carry no gripping jaw at all, so a job needing both cutting and holding still calls for a combination or needle nose pliers alongside them.
Read AIMS's full Types of Pliers Guide →
Shop AIMS's range of mixed plier sets →
What Is Silicone Spray?
Silicone spray is a water-resistant, non-staining lubricant and release agent, used anywhere Penetrating Oil would leave an oily residue or attract dust — rubber and plastic seals, door tracks, hinges, and release applications where a part needs to not stick to a mould or fixture rather than needing heavy-duty lubrication. Food-grade (NSF H1) versions exist for food and beverage processing environments, the same certification standard covered under Food Grade Grease.
Read AIMS's full Silicone Spray Guide: Uses, Food-Grade & Where Not to Use It →
Shop AIMS's range of silicone spray →
What Is Simplex Roller Chain?
Simplex roller chain is standard single-strand roller chain — one strand of pinned links and rollers running on a given pitch and sprocket, as opposed to the multi-strand Duplex Roller Chain and Triplex Roller Chain used to multiply load capacity without changing pitch size.
It's the base configuration nearly all roller chain drives start from, and the right choice whenever the drive's load rating doesn't call for the extra capacity — and extra cost and width — of a multi-strand chain. See Roller Chain Anatomy for what it's actually built from.
Read AIMS's full Roller Chain Guide →
Shop AIMS's range of chain & sprockets →
What Is a Single-Phase Fan/Heater Supply?
A single-phase fan/heater supply is standard 240V power — the same supply as a household wall socket — delivered on a single alternating current phase. It's what most portable and light-to-mid industrial fans, evaporative coolers and heaters are designed to run on, typically up to somewhere around 9 kW depending on the circuit's rated amperage.
In practice the ceiling steps up in stages: a small electric heater or fan under about 2.4 kW runs fine off a standard 10A wall socket; 2.4–3.6 kW needs a 15A circuit; and heavier industrial gear in the 5–9 kW range needs a dedicated 20A or 32A single-phase circuit before a Three-Phase Fan/Heater Supply becomes the only option. This is about the electrical supply feeding a fan or heater's own motor and controls, not the internal winding or starting configuration of an electric motor — a related but different subject that AIMS's glossary also covers, in its Electrical category, single-phase and three-phase electric motor terminology (motor winding configuration and starting methods), for anyone who actually landed here looking for that instead.
Read AIMS's full Industrial Heating Guide and Industrial Cooling Guide →
Shop AIMS's range of HVAC & refrigeration equipment →
What Is a Single-Phase Motor?
A single-phase motor runs on Australia's standard 230–240V single-phase supply, available at a standard GPO — the everyday power point — rather than needing a dedicated three-phase connection. It's practical for loads up to roughly 2.2 kW, covering most bench grinders, small pumps, fans and light conveyors, and it's the only option where three-phase power simply isn't available on site.
A single-phase motor can't self-start on its own — the single-phase stator field pulsates rather than rotates, producing no net starting torque — so it needs an auxiliary starting method; see Capacitor Start / Capacitor Run for the four ways this is solved. Where load and site permit a choice, a Three-Phase Motor is generally the better option above the smallest loads: better starting torque, higher efficiency, cooler running and no capacitors to periodically check and replace.
Read AIMS's full Electric Motor Guide → for the full single-phase vs three-phase comparison table
Shop AIMS's range of electric motors →
What Is a Single-Stage Regulator?
A single-stage gas regulator drops cylinder pressure down to working delivery pressure in one mechanical step — simpler and cheaper than a Dual-Stage Regulator, but prone to Regulator Droop, where delivery pressure gradually creeps upward as the cylinder empties.
It's perfectly adequate for shorter jobs, intermittent MIG welding or general workshop use, where a bit of pressure creep over a cylinder's life isn't going to be noticed — a genuine cost-versus-precision trade-off against the dual-stage option rather than one type simply being "better." Like the dual-stage type, it's still built to the AS 4267 — Gas Regulator Standard (Type 10 Inlet) requirements for inlet fitting, safety relief and pressure rating.
Read AIMS's full Welding Gas Regulator Guide →
What Is SKD? (Semi-Knocked-Down)
SKD stands for Semi-Knocked-Down — equipment or vehicles shipped partially assembled, sitting between CBU (fully built) and CKD (fully disassembled) on the same spectrum of import and assembly strategies.
An SKD shipment typically arrives as a small number of major sub-assemblies rather than either a finished unit or every individual component, requiring a simpler final assembly step than a full CKD build while still gaining some of the freight and duty advantages of shipping equipment partly broken down. The right choice between CBU, SKD and CKD for a given piece of imported equipment usually comes down to a mix of freight cost, import duty structure and how much local assembly capability and labour is actually available.
What Is Skirting? (Skirt Board, Conveyor)
Conveyor skirting is a rubber sealing strip clamped along a steel skirt board frame that runs above the belt edges at a loading or transfer zone, containing the material stream to the centre of the belt while it settles after impact. "Skirting" is the rubber sealing element itself; "skirt board" is the steel frame it clamps to — in everyday trade conversation the two terms are often used interchangeably for the whole assembly.
Correctly set skirting is one of the most cost-effective fixes for spillage and dust generation on a belt conveyor — set too tight and it accelerates Cover Compound (Conveyor Belt) wear and can damage the belt edge; set too loose and material escapes underneath it. It's specified alongside a Transfer Point (Conveyor)'s chute and impact bed design, since all three work together to control material and dust at the point of highest turbulence on the conveyor.
What Is SKU? (Stock Keeping Unit)
SKU stands for Stock Keeping Unit — a unique code assigned to a specific product variant (a particular size, grade, pack quantity or finish) so it can be individually tracked through ordering, inventory, warehousing and sales.
Every distinct product line a supplier stocks — down to each size and variant — gets its own SKU, which is what makes it possible to know exactly what's in stock, reorder the right thing and quote accurately, rather than dealing in vague product descriptions. With AIMS carrying well over 100,000 product lines, SKU-level tracking (tied to Inventory counts and UOM) is exactly what makes a catalogue that size searchable and orderable in practice.
What Is a Slack Adjuster?
A slack adjuster is the lever arm connecting a Brake Chamber's push-rod to the S-Cam in a drum-type Air Brake System, converting the chamber's linear push into the rotating motion that applies the brake shoes. As the brake linings wear over time, the effective "slack" in this linkage increases; an automatic slack adjuster (ASA) — now standard on most Australian heavy vehicles — continuously takes up that wear on its own, where older manual slack adjusters needed periodic mechanical adjustment to keep the S-cam rotation, and therefore braking performance, within spec.
What Is Slag? (Welding)
Slag is the layer of solidified flux by-product that forms over a stick (SMAW / MMA) weld bead as the electrode's Flux Coating (Stick Electrode) burns and cools, protecting the still-hot weld metal from oxidation while it solidifies. It's not part of the finished weld — it's a temporary shield, chipped or wire-brushed away once the bead has cooled enough to handle.
Removing slag properly between passes isn't optional on a multi-pass weld: any slag trapped between layers becomes a slag inclusion — a genuine weld defect that weakens the joint and can fail inspection or non-destructive testing on structural work. How readily slag lifts off depends on the electrode's flux type: cellulosic electrodes (like E6010) produce a thin, fast-freezing slag that's easy to remove, while basic/low-hydrogen electrodes (like E7018) leave a denser slag layer that needs a firmer chip. Note that MIG and TIG welding, which use a Shielding Gas rather than a flux coating, don't produce slag at all — it's a stick-welding-specific by-product.
Read AIMS's full Stick Welding Guide →
What Is a Sledge Hammer?
A sledge hammer is a large, heavy, double-faced hammer swung with both hands, built for high-impact work a single-handed hammer can't deliver — demolition, driving stakes and posts, breaking up masonry, and heavy fabrication or assembly work.
Head weight is the main selection variable, commonly running from around 1.8 kg (4 lb) short-handled versions for confined or lighter work up to 5.5–9 kg (12–20 lb) long-handled versions for genuine demolition and heavy driving work — the heavier and longer the sledge, the more force it delivers per swing, at the cost of control and fatigue over a long job.
Read AIMS's full Hammer Types Guide →
What Is Sling Angle Deration?
Sling angle deration is the reduction in a sling's usable Working Load Limit as the angle between the sling leg and the horizontal decreases from vertical — the shallower the angle, the more of the sling's tension goes into pulling the legs apart rather than lifting the load, and the lower its effective capacity. As a rule of thumb, a sling at 60° from horizontal still carries about 87% of its vertical WLL, at 45° that drops to about 71%, and at 30° — generally treated as the practical minimum angle for rigging — it's down to 50%. This applies on top of, not instead of, the Hitch Type deration, so a choked sling rigged at a shallow angle can end up rated far below its tag figure.
What Is Sling Ply (Webbing Sling)?
Sling ply describes how many layers of webbing are stitched together through a synthetic webbing sling's cross-section — 1-ply is the lightest and most flexible for a given WLL and suits general workshop use, while 4-ply is heavier, stiffer and considerably more abrasion-resistant, suiting heavy industrial or high-cycle environments where the sling will be dragged over rough surfaces repeatedly. Both AS 1353 (flat webbing) and AS 4497 (round slings) mandate an 8:1 safety factor regardless of ply — a 1-tonne sling always has a minimum breaking load of at least 8 tonnes. See WLL Colour Code below for how to read a sling's rating at a glance.
Read AIMS's full Webbing & Round Slings Guide → for ply, colour code and inspection criteria
What Is Slip (Motor)?
Slip is the difference between an induction motor's synchronous speed (the theoretical speed set purely by supply frequency and Poles count) and its actual full-load rotor speed — typically 3–5% in a standard induction motor. It's exactly why a 4-pole motor's nameplate reads roughly 1,450 RPM rather than the theoretical 1,500 RPM synchronous speed calculated from pole count alone: the rotor always lags slightly behind the rotating magnetic field, and it's that lag — not a manufacturing tolerance or a fault — that actually produces the torque driving the rotor around. Slip generally increases as load (and therefore torque demand) increases, which is why a heavily loaded motor's actual speed sits further below synchronous speed than a lightly loaded one.
Read AIMS's full Electric Motor Guide → for the pole count/synchronous speed/slip reference table
What Is a Slot Drill?
A slot drill is a two-fluted end mill capable of plunging straight down into solid material to start a cut, unlike a standard end mill, which generally needs to enter from the side or a pre-drilled hole. That plunge capability is what makes a slot drill the standard choice for milling a slot or starting a pocket from solid stock in one operation, rather than needing a separate drilled entry hole before milling can begin.
Read AIMS's full End Mill Guide → for flute counts, coatings and end mill selection
Shop AIMS's range of end mills & milling cutters →
What Is a Slotted Shank?
A slotted shank describes the single longitudinal slot cut along a slotted spring pin (roll pin) — a rolled sheet of spring steel formed into a cylinder with one continuous split down its length, compressed slightly to fit a drilled hole and relying on its own spring-back pressure against the hole wall to stay in place.
The slot's orientation matters on installation: for load-bearing use, the slot should be oriented perpendicular to the primary load direction, since the slot itself is a stress-concentration point and incorrect orientation can meaningfully reduce service life under repeated loading. A Coiled Spring Pin (DIN 1482/ISO 8750) is the alternative, slot-free design — multiple wraps of spring steel rather than one slotted tube — offering better fatigue resistance and no orientation requirement, at a cost premium.
Read AIMS's full Roll Pin Guide → for slotted vs coiled spring pin comparison and installation technique
Shop AIMS's range of spring pins →
What Is SMAW / MMA? (Stick Welding)
SMAW (Shielded Metal Arc Welding) and MMA (Manual Metal Arc) are two names for the same process that's universally known on an Australian tools as "stick welding": a flux-coated consumable electrode is struck against the workpiece to form an arc, and as it melts, the flux coating burns to form a shielding gas and a protective slag layer over the cooling weld. SMAW is the American (AWS) name; MMA is the name used in Australian and European standards (including AS 2812, the Australian welding glossary) and on most Australian welder nameplates and trade training material — the two are used almost interchangeably here, unlike the genuinely search-split MIG/GMAW and TIG/GTAW pairs, so this entry covers both names together rather than splitting them.
Stick welding needs no shielding gas bottle and tolerates wind, rust, mill scale and outdoor conditions far better than MIG or TIG, which is exactly why it's the go-to for site repairs, pipeline work and maintenance welding away from a clean workshop. Which electrode to load depends entirely on the job — see SMAW Electrode Classification (E6013/E7018/E6010/E7024) — and getting the DCEP / DCEN (Welding Polarity) setting right for that electrode is non-negotiable for arc quality.
Read AIMS's full Stick Welding Guide and MIG vs TIG vs Stick Welding Guide →
Shop AIMS's range of Gemini stick welding electrodes →
What Is SMAW Electrode Classification? (E6013 / E7018 / E6010 / E7024)
The AWS A5.1 electrode classification code stamped on every stick electrode packet — E6013, E7018, E6010, E7024 and similar — tells a welder exactly what the rod is made of and how to run it, without needing to open a datasheet. The "E" means electrode; the first two digits give minimum tensile strength in ksi (60 or 70, i.e. roughly 414 MPa or 483 MPa); the third digit sets which welding positions the rod can run in; and the fourth digit specifies the flux coating type and recommended DCEP / DCEN (Welding Polarity).
The four most common Australian workshop grades cover very different jobs: E6013 (rutile flux, AC/DCEN/DCEP) is the beginner-friendly, general-purpose all-rounder with a soft, forgiving arc; E7018 (basic/low-hydrogen flux, DCEP) is the structural and pressure-pipe standard, prized for toughness but demanding dry rod-oven storage once opened; E6010 (cellulosic flux, DCEP only) delivers an aggressive, deep-penetrating arc suited to pipeline root passes and rusty or dirty steel; and E7024 (iron-powder flux, AC/DCEN/DCEP) is the fast-fill choice for flat and horizontal fillet welds. Each classification's Flux Coating (Stick Electrode) is what determines its arc character, penetration and required polarity — running an electrode outside its designed polarity range produces a poor arc and porous welds.
Read AIMS's full Stick Welding Guide and Welding Consumables Guide →
Shop AIMS's range of Gemini stick welding electrodes →
What Is a Snap Ring (Retaining Ring)?
A snap ring — also called a circlip in Australian trade usage — is an internal or external retaining ring seated in a machined groove to axially locate a bearing, gear or other component inside a bore or on a shaft. In a Bearing application specifically, an external snap ring in the housing bore, or an internal one on the shaft, does the same job a Shaft Collar does on plain shafting: it stops the bearing sliding axially without needing a full shoulder.
See the existing Retaining Ring entry in this glossary for the fuller circlip family (internal, external, E-clip, spiral) and how they're selected and installed.
Shop AIMS's range of retaining rings →
What Is a Snatch Block?
A snatch block is a pulley block with a hinged side plate, which opens to let a wire rope or cable be loaded onto the Sheave mid-line rather than having to thread it through end-to-end. This is what makes a snatch block practical for winching and load-redirection work in the field, where re-threading a standard pulley block isn't an option — the same fixed-vs-travelling distinction that separates it from a Deflection Pulley.
The block's own WLL isn't simply the winch's pulling capacity, either — a snatch block used to redirect a line carries the *sum* of the tension in both rope legs either side of it, which can be up to double the line tension where the two legs run roughly parallel. Where the actual angle between the legs isn't known in advance, the safe rule AIMS's own rigging guidance uses is to rate the block at twice the maximum expected line load — a 4,500 kg winch line, for instance, calls for a block rated to at least 9,000 kg WLL, not 4,500 kg. See Sheave (Pulley Wheel) for the sheave-to-rope diameter (D:d) sizing ratio that also governs a snatch block's selection.
Read AIMS's full Snatch Block Guide → for the full D:d ratio and block-load tables
Shop AIMS's range of blocks and sheaves →
What Is a Socket-on-Hex Adapter?
A socket-on-hex adapter mounts a standard socket onto a hex-shank adapter, giving mixed-size flexibility from an existing socket set rather than needing a dedicated Nutsetter for every size.
It's the flexible option when a job needs several different sizes and a full nutsetter set isn't on hand — trading some of the speed of a dedicated Nutsetter or Nut Driver for that flexibility. *(General hand-tool terminology — no dedicated AIMS article or collection for the adapter itself.)*
What Is a Soft Starter?
A soft starter is an electronic (thyristor/SCR-based) unit that ramps a motor's voltage up gradually over a set time — typically 2 to 30 seconds — rather than switching it on in one step like DOL (Direct-On-Line) Starting or in two steps like Star-Delta (Y-Δ) Starting. There's no mechanical transition to time or maintain, and no special six-lead winding requirement — starting current typically runs 2.0–4.0 times FLA depending on how the ramp is configured, and most soft starters bypass into a direct connection once the motor is up to speed.
A soft starter controls only the start, not the running speed — once up to speed, the motor runs at fixed supply frequency, which is the key difference from a VFD (Variable Frequency Drive). It's often the safest default starting method when you're not certain which of the four methods a site needs: smoother and more reliable than star-delta (no switching-transition current spike, no contactor-welding risk), and cheaper than a VFD wherever variable speed genuinely isn't needed. A soft starter must be rated for the load's real starting duty, not just the motor's running current — a load needing genuine breakaway torque (an agitator restarting under a settled load, for instance) needs a soft starter sized for that, not just for the nameplate amps.
Read AIMS's full Motor Starting Methods Guide → for the full starting-current and cost comparison
What Is a Soft-Face Hammer?
A soft-face hammer has a replaceable striking face — nylon, rubber, copper or rawhide — built to drive or shape a finished workpiece without marking, denting or bruising its surface the way a steel-faced hammer would.
Because the face is replaceable, a worn or damaged striking face can be swapped out rather than replacing the whole hammer, and different face materials suit different jobs: nylon and rubber for general assembly work on painted or plated surfaces, copper and rawhide for heavier, more direct striking where a softer nylon face would deform too quickly. See Mallet for the broader family of soft-headed striking tools this hammer type belongs to.
Read AIMS's full Hammer Types Guide →
Shop AIMS's range of Thor mallets & hammers →
What Is a Solenoid Valve?
A solenoid valve is an electrically-operated valve that opens or closes using a solenoid coil — energising the coil creates a magnetic field that pulls a plunger to shift the valve between its two states, giving fast, remote on/off control from an electrical signal rather than a manual handle or lever.
Two base configurations cover most industrial and pneumatic use: normally closed (the default, no-power state is shut, and energising the coil opens it — the safer default for most fluid and gas control, since a power failure leaves the line closed) and normally open (the default state is open, and energising the coil shuts it — used where a system needs to keep flowing if power is lost). Direct-acting solenoid valves use the coil's force alone to shift a small orifice directly, suiting low-flow, low-pressure duty; pilot-operated (servo-assisted) solenoid valves use a small solenoid-controlled pilot flow to shift a larger main valve using the line's own pressure, which is how a small, low-power coil can control a comparatively large industrial flow. A solenoid valve has no built-in throttling capability — it's a fast on/off device, not a metering one — so it's typically paired with a separate flow control or Needle Valve immediately downstream wherever the application also needs to set a precise flow rate, not just switch it on and off.
What Is Spalling (Flaking)?
Spalling — also called flaking — is fatigue-driven surface damage to a bearing's Race: pitting and cratering that progressively breaks away material from the running surface. Reaching this point is actually the expected end of a correctly loaded bearing's calculated service life, not necessarily a sign anything went wrong — but spalling that shows up well ahead of that expected life is a strong signal of overloading, contamination, or an incorrect Interference Fit at installation.
AIMS's own maintenance guide notes that a rhythmic knocking noise matching the ball-pass frequency of the bearing is a typical symptom of a spalled raceway or a damaged rolling element, and calls for replacement rather than further monitoring once that's confirmed.
Read AIMS's full Bearing Maintenance: Inspection, Lubrication & Replacement Guide →
What Is a Spanner? (Wrench)
A spanner — wrench in American usage — is a fixed-size hand tool for gripping and turning a nut or bolt head, sized to fit one specific fastener rather than adjusting to fit a range like a Crescent Wrench.
Three head styles cover most trade work: open-end (a two-sided open jaw, fast to apply from the side but grips only two of a hex head's six faces), ring/box (a fully enclosed hex or 12-point opening that grips all faces and won't slip off, but must be dropped over the fastener end-on), and combination (open-end on one end, ring on the other, on a single handle — the default general-purpose spanner in most kits). Getting the correct size matters as much as the head style: a spanner even slightly oversized for its fastener rounds the corners under load, which is exactly the failure a correctly-fitted ring spanner over an adjustable wrench is meant to avoid.
Read AIMS's full Spanner & Shifter Guide and Spanner Size Chart →
Shop AIMS's range of spanners & wrenches and open end wrenches →
What Is SPC (Statistical Process Control)?
SPC (Statistical Process Control) is a quality-management method that uses statistical sampling and control charts to monitor a manufacturing process in real time, distinguishing normal process variation from a genuine, correctable shift — so a process can be adjusted before it actually starts producing out-of-Tolerance parts, rather than relying purely on inspecting finished parts after the fact. It sits alongside GD&T and gauge-based inspection (GO / NO-GO Gauge) as one of the three main levers a quality system uses to keep a production process in control, and the calibration Traceability of the measuring equipment feeding an SPC chart is what makes the chart's data trustworthy in the first place. *(General engineering fundamentals — no dedicated AIMS article for this term.)*
What Is a Speed Nut?
A speed nut (spring steel push nut) is a stamped, spring-steel clip designed to be pushed directly onto a bolt, stud or shaft and grip via spring tension against the thread or a plain shaft, giving a fast, tool-minimal fastening for light-duty trim, panel and automotive applications where a conventional nut and washer would be slower to fit.
Speed nuts trade holding strength for installation speed — they're the right choice for interior trim panels, light brackets and non-structural automotive fastening, but are not a substitute for a proper hex or lock nut anywhere genuine clamp force or vibration resistance matters.
Shop AIMS's range of speed nuts →
What Is a Spherical Roller Bearing?
A spherical roller bearing uses a double row of barrel-shaped rollers running on a curved (spherical) outer race, which combines heavy radial and moderate axial load capacity with self-alignment — tolerating around 1.5° of misalignment, on top of what a Self-Aligning Ball Bearing manages, but at much higher load. AIMS's own guide flags it as the most robust bearing type for heavy, contaminated industrial environments — conveyors, crushers, vibrating screens and similar plant where shock load and dirt ingress are routine.
Read AIMS's full Rolling Bearings: Types, Selection, Fitting & Failure Guide →
Shop AIMS's range of spherical roller bearings →
What Is a Spill Kit?
A spill kit is a pre-packaged set of absorbent socks, pads and containment materials kept on-site to quickly contain and clean up a chemical, oil or fuel spill before it spreads, reaches drains or waterways, or creates a slip hazard.
Kit selection follows the hazard class of what's being stored or handled — the same AS 1940 liquid-storage classification that governs tank and bunding requirements also informs which absorbent chemistry and kit size are appropriate for a given site, since an oil-only absorbent won't necessarily be the right choice for a general chemical spill.
Read AIMS's full Spill Kit Guide →
What Is a Spin-Pull Tool? (vs Spin-Spin)
Spin-pull and spin-spin describe two different rivet nut tool mechanisms: a spin-pull tool spins the mandrel to thread it into the nutsert, then pulls it to set the fastener in one motion; a spin-spin tool spins the mandrel both to thread it in *and* to unthread it back out after setting, without needing a separate pull stroke or manual unscrewing step.
Spin-spin tools are generally the faster, more consistent option for production-volume rivet nut installation, since the operator doesn't need to manually unscrew the mandrel between fasteners — the tool's own reverse-spin does it. Lighter plier-style and lever tools are typically spin-pull by design; higher-tier pneumatic and cordless rivet nut tools are more commonly spin-spin. *(General fastening-industry terminology, within the tool-tier range AIMS's own rivet nut guide covers.)*
Shop AIMS's range of pop rivet guns & nut riveters →
What Is Spinning Out?
Spinning out describes the failure of an anti-rotation fastener — most often a nutsert or a wall anchor — to grip its hole, so that instead of tightening a mating screw or bolt, the whole fastener simply rotates freely inside the hole with the fixture.
For a rivet nut, this typically means the body wasn't set correctly against a hard enough material or with enough anti-rotation feature (a smooth round body in soft aluminium being the classic failure case — see Full Hex and Knurled Shank above for the anti-rotation body styles that address this directly). For a wall plug in plasterboard, it means the plug has widened the hole rather than gripping it, which is why AIMS's own wall plug guide flags standard plugs as unsuitable for plasterboard outright. *(General fastening-industry terminology, cross-referenced against AIMS's rivet nut and wall plug guides.)*
What Is a Spring (Fastener Context)?
In a fastening context, spring most often refers to a spring washer or spring pin — a component that uses stored elastic force to maintain tension or grip in a joint, rather than the coil compression/extension/torsion springs used in machinery.
A spring washer (split lock washer, DIN 127, or the more effective conical Schnorr-type to DIN 6796) sits under the nut or bolt head and is compressed slightly on tightening, aiming to maintain some residual clamp force if the joint loses a small amount of tension. A spring pin (roll pin) is a rolled or coiled length of spring steel that's compressed slightly to fit a drilled hole and relies on its own spring-back pressure to stay in place — see Slotted Shank below for the specific slotted-tube version. AIMS also stocks conventional compression, extension and torsion springs as a separate mechanical-component range.
Shop AIMS's range of springs →
What Is a Sprocket?
A sprocket — also called a sprocket-wheel or chain wheel — is a toothed wheel that engages a roller chain to transmit rotational power between shafts, the chain-drive equivalent of a pulley and belt (see Pulley in the Belts & Drives category).
Pitch is the non-negotiable match point between a sprocket and its chain: the tooth spacing has to align exactly, and ANSI and ISO/BS chain aren't interchangeable even where the nominal pitch looks similar, since roller diameter and inner width differ between the two standards. Tooth count matters too — AIMS's own roller chain guide recommends an odd tooth count (17T, 19T, 21T…) on the driver sprocket paired with an even link count, so every link engages a different tooth each revolution and wear spreads evenly across the sprocket rather than concentrating on the same teeth, with a minimum 120° wrap angle on the smaller sprocket to stop the chain jumping.
Read AIMS's full Roller Chain: Sizes, Types & Sprockets Guide →
Shop AIMS's range of chain and sprockets →
What Is a Square Washer?
A square washer is a flat washer with a square outer profile rather than the standard round shape, used mainly with square-shank fasteners (coach bolts, some U-bolts) or on timber, where the larger flat bearing area and square shape resist rotation and spread load without indenting soft or fibrous material the way a smaller round washer might.
Square washers are a specialty rather than general-purpose item — most bolted-joint work uses standard round flat washers to DIN 125/ISO 7089 — and are reached for specifically where the square profile itself solves a rotation or bearing-area problem a round washer wouldn't. *(General fastening-industry terminology — no dedicated AIMS article specifically on square washers, though they sit within AIMS's broader washer range.)*
Shop AIMS's range of washers →
What Is Stainless Steel? Austenitic, Duplex, Ferritic, Martensitic and PH Explained
Stainless steel is steel alloyed with a minimum of around 10.5% chromium, which forms a thin, self-healing chromium-oxide layer on the surface that gives it corrosion resistance ordinary carbon steel doesn't have. Which of the five main stainless families it belongs to — austenitic, ferritic, martensitic, duplex or precipitation-hardening (PH) — depends on its internal crystal structure and alloy content, and determines its strength, corrosion resistance and whether it's magnetic.
Austenitic stainless (grades 304/A2 and 316/A4) is the common non-magnetic, weldable, general-corrosion-resistant family used for most fasteners and fittings — see 304 Stainless Steel and 316 Stainless Steel for the difference between them. Ferritic and martensitic stainless are magnetic, generally cheaper, and used where hardness (martensitic, like cutlery-grade steel) or moderate corrosion resistance at lower cost (ferritic) matters more than maximum corrosion resistance. Duplex Stainless Steel combines roughly equal austenitic and ferritic structure for higher strength and corrosion resistance than standard austenitic grades. PH (precipitation-hardening) stainless is a specialised, heat-treatable high-strength family used in aerospace and highly demanding engineering applications, rarely stocked in general industrial supply.
Read AIMS's full Stainless Steel Fastener Grades guide →
Shop AIMS's range of Inox World stainless fasteners →
What Is STAMP(S)? (Valve & Fitting Selection)
STAMP is the industry-standard checklist for selecting a fitting, hose or valve: Size (the port or tube size and wall thickness a component needs to handle), Temperature (both the fluid's operating temperature and the surrounding ambient conditions), Application (what the component actually needs to do in the system), Media (the specific fluid or gas being handled, which drives material compatibility), and Pressure (the system's working and surge pressure).
Working through STAMP in order before specifying a part catches the two most common selection mistakes: picking a component rated for the wrong media (a seal or body material that looks fine on paper but fails against the actual chemical in the line) and picking one rated for the wrong pressure once temperature de-rating is accounted for, since almost every pressure rating quoted on a spec sheet assumes room temperature. See STAMPED for the fuller six-letter version used specifically for valve selection.
What Is STAMPED? (Valve Selection)
STAMPED extends STAMP(S) with two more selection criteria specific to valves: End connections (whether the valve needs integral tube fittings, pipe threads, flanges, welded ends or a grooved coupling to match the rest of the system) and Delivery (whether the manufacturer can actually supply and support the part reliably, which matters as much as the technical spec on a job with a deadline).
The full checklist — Size, Temperature, Application, Media, Pressure, End connections, Delivery — is the standard method engineers and maintenance teams use to move from "I need a valve" to a specific, correctly-rated part number, rather than guessing from habit or picking whatever's on the shelf.
What Is Star-Delta (Y-Δ) Starting?
Star-delta (also written Y-Δ) is a reduced-voltage starting method for three-phase Induction Motors. The motor must be specifically wound for star-delta operation (six leads brought out, not three) — during start, the three windings are connected in star configuration, so each winding sees only phase voltage (240V from a 415V supply), cutting starting current to roughly 2.0–2.7 times FLA. Once the motor is near full speed, a second contactor switches the windings to delta for full-voltage running.
The saving on starting current comes with a real trade-off most guides skip over: the star-to-delta transition isn't seamless. That switching moment causes a brief current and torque spike — rarely an issue on smaller motors, but on larger motors it's a documented mechanical risk serious enough in some cases to shear a motor shaft outright. The transition timer and mechanical interlock between the star and delta contactors also need to be correctly set and maintained — a mistimed or drifted transition timer is a recurring, documented cause of the two contactors welding shut during changeover, tripping the whole board. For frequently-cycling loads or larger motors, a Soft Starter avoids both risks since it has no equivalent mechanical transition to get wrong.
Read AIMS's full Motor Starting Methods Guide → for the full four-method comparison and the star-delta transition risk in detail
What Are Steel Cap Boots?
Steel cap boots are Safety Footwear fitted with a steel toecap, certified in Australia under AS/NZS 2210.3 to withstand a 200-joule impact and 15 kN static compressive load — the traditional, most widely recognised form of protective footwear.
Steel toecaps are cheaper, thinner and don't fatigue or crack under normal wear, but they conduct electricity (unsuitable for electrical work without an EH-rated sole), add 150–300 g of weight per boot, and set off metal detectors — trade-offs worth weighing against Composite Toe Boots for a specific job.
Read AIMS's full Steel Cap Boots Guide →
Shop AIMS's range of safety footwear →
What Is a Steel Rule?
An engineer's steel rule is a thin, flexible, hardened stainless-steel ruler with precision-etched graduations on both edges, designed for marking out and everyday measurement to about ±0.1mm or better — used for dimensioning workpieces, setting a Calliper to a reference dimension, and checking edge straightness. It's the lowest-cost, highest-volume measuring tool in most trades, and belongs alongside the Engineer's Square and Combination Square as the everyday workshop measuring trio, each suited to a different everyday job rather than one replacing the others.
Read AIMS's full Engineers Square, Combination Square & Steel Rule Guide → for the full comparison
Shop AIMS's range of measuring tools →
What Is Steel Wool?
Steel wool is a bundle of extremely fine steel fibres, graded from coarse (heavy rust and paint removal) through to superfine (final surface prep before finishing, and light metal polishing). It sits between Emery Cloth and a Scotch-Brite® pad in how it's used by hand — more aggressive than a fine non-woven pad, but without the sharp, directional scratch pattern of a coated abrasive — which is why it's still reached for on jobs like de-scaling, key and lock lubrication prep, and fine timber finishing between coats.
Read AIMS's full Non-Woven Abrasive Pad & Disc Guide → for how Scotch-Brite®-style pads compare and where each one fits.
What Is Strain Relief?
Strain relief is any fitting or design feature that stops mechanical force on a cable — from being pulled, flexed, knocked or vibrated — from transferring through to the electrical termination itself. A Cable Gland is the most common source of strain relief at an enclosure entry point, clamping the cable's outer sheath so that ordinary handling and vibration can't work the connection loose or fatigue the conductor at the join.
What Is Stress / Strain?
Stress is the internal force a material experiences per unit of cross-sectional area, measured in pascals or psi (see the Kip / kN / MPa / PSI cluster above); strain is the resulting deformation, expressed as the ratio of the change in length to the original length — dimensionless, or given as a percentage. Plotting stress against strain for a test sample produces the stress-strain curve that defines a material's Elastic Range, yield point, ultimate tensile strength and Fracture Point — each of those terms above describes a specific point or region on that same curve, rather than being separate, unrelated concepts. *(General engineering fundamentals — no dedicated AIMS article for this term.)*
What Is Stress Relieving?
Stress relieving is a heat-treatment step that removes internal stresses left in a metal part by welding, machining, Cold Working or uneven cooling, without significantly changing its hardness or strength.
Unrelieved internal stress can cause a part to warp, crack or distort — sometimes not immediately, but weeks or months after fabrication, once the stress finds a way to release itself. Stress relieving is common practice on welded steel fabrications and precision-machined components before final machining passes, so the part doesn't move once the last cut is made.
What Is the Stroke (Rivet Gun)?
Stroke is the distance a rivet gun's jaws or mandrel-pulling mechanism travel in a single squeeze, trigger pull or cycle — it determines how much mandrel length the tool can pull through in one action, which directly limits the largest rivet diameter and grip range the tool can set.
A short-arm hand riveter typically needs three to four squeezes to fully set a standard rivet because its stroke is short; a lever (long-arm) riveter's extended handles deliver a longer stroke and higher force per squeeze, letting it set the largest blind rivets (5/16", 6.4 mm) in far fewer strokes; a pneumatic riveter completes the full stroke automatically in about two seconds per rivet. *(General fastening-industry terminology, cross-referenced against AIMS's own rivet gun guide.)*
Read AIMS's full Rivet Gun Guide → for stroke, force and cycle time by tool type
What Is a Structural Acrylic?
Structural acrylic is a high-strength, two-part adhesive designed to bond dissimilar materials — aluminium to steel, composites to metal, coated materials to each other — without heat and without the distortion a weld would introduce, typically achieving shear strengths above 20 MPa on steel, aluminium and stainless steel.
It bridges gaps of up to 5 mm, fixtures in 20–40 minutes at 23°C and reaches full cure in 24 hours. In genuine fatigue applications, adhesively bonded structural acrylic joints frequently outperform welds — making it a real engineering alternative in dissimilar-material assemblies, not just a workshop convenience.
Read AIMS's full Industrial Adhesive Types Guide →
Shop AIMS's range of adhesives, sealants & tapes →
What Is a Structural Rivet?
A structural rivet is a blind rivet engineered specifically for load-bearing joints where a standard pop rivet's strength is insufficient — see Bulb rivet above for the mandrel-locking mechanism that gives structural rivets their much higher shear ratings (typically 8–15 kN, against a fraction of that for a standard pop rivet).
AIMS's own guide is explicit that standard pop rivets are not structural fasteners — using one where a structural or lock-bolt rating is actually required is a genuine safety issue, not just an over-engineering question. Structural rivets sit as the mid-tier option between a standard blind rivet and a full Lock Bolt system, and branded examples (Gesipa® BULB-TITE®, Huck Magna-Lok®) are specified by name in structural fabrication drawings precisely because generic "blind rivet" doesn't guarantee the required strength.
Read AIMS's full Types of Rivets Guide → for structural rivet shear ratings and material-pairing warnings
Shop AIMS's range of rivets →
What Is a Swage (Fastener Context)?
To swage is to permanently deform or compress a metal component — a collar, a fitting, a rivet body — around another part using controlled radial pressure, forming a permanent mechanical joint without heat, adhesive or a separate threaded fastener.
In fastening, swaging is the mechanism behind a Lock Bolt system (a tool swages the collar into the grooved pin's ribs) and behind swaged wire rope terminals and fittings in rigging work. It's distinct from crimping (which typically compresses a softer sleeve around a wire or cable rather than locking two hard components together) and from riveting proper (which relies on a rivet body deforming to fill and clamp a hole, rather than a separate collar compressing onto ribs). *(General engineering fundamentals — no dedicated AIMS article specifically on swaging as a fastening process, though it underlies AIMS's lock bolt and wire rope terminal coverage.)*
What Is SWG (Standard Wire Gauge)?
SWG (Standard Wire Gauge), also called British Standard Wire Gauge, is a legacy wire sizing system that predates and differs numerically from AWG (American Wire Gauge) — the same gauge number means a different actual wire diameter under each system. It still turns up on older UK-origin and Commonwealth equipment and drawings, which is why checking which gauge system a spec is using, rather than assuming AWG, matters when sourcing a like-for-like replacement wire.
What Is a Swivel Hoist Ring?
A swivel hoist ring is a bearing-mounted lifting point that rotates 360° around its shank and pivots a further 180° in the perpendicular plane, letting it carry its full rated WLL at any load angle — unlike a standard Eye Bolt, even a collared one, which still needs an angular de-rating calculation applied. Where a lifting point will regularly be pulled from different directions, a swivel hoist ring is usually the safer and simpler choice over working out eye bolt de-ratings on every lift.
What Is a Synchronous (Timing) Belt?
A synchronous belt — commonly called a timing belt — is a toothed belt that engages matching teeth on its sheaves for positive, no-slip power transmission, rather than relying on friction the way a V-belt does.
Because there's no slip, a synchronous belt keeps a driven shaft in an exact, repeatable phase relationship with the driver — essential for camshaft timing and indexing applications, and the reason it holds the highest efficiency of any common drive type at roughly 97–99%, against 92–96% for a V-belt and 96–98% for a well-lubricated Roller Chain Drive. It also runs at up to roughly 60 m/s belt surface speed, twice a V-belt's practical ceiling. The trade-off against chain is a lower tolerance for genuine shock loading, since torque is carried through tooth shear rather than a chain's link-and-pin engagement. See Timing Belt (Base Term) for the everyday name this same component goes by in general conversation.
Read AIMS's full Belt vs Chain Drives Guide →
Shop AIMS's range of industrial drive & conveyor belts →
T
What Is a T-Nut?
A T-nut is a flanged, barrel-shaped threaded fastener with sharp prongs on its flange, designed to be hammered or pressed into wood or composite sheet material — the prongs bite into the surrounding material and stop the T-nut from spinning once a bolt is threaded into it from the opposite face.
T-nuts are specifically a wood/composite fastener rather than a metal-to-metal one — AIMS's own guide is explicit that they're "not used in metal-to-metal assemblies," where a Rivnut / Rivet Nut or Captive Nut does the equivalent job instead. Common uses include workbenches, jigs, cabinetry and any bolted connection into the flat face of a timber or composite panel.
Read AIMS's full Types of Nuts Guide → for T-nut and other specialty nut types
Shop AIMS's range of tee nuts →
What Is Tack? (Adhesive)
Tack is how quickly and firmly an adhesive grips a surface on initial contact, before any curing has taken place — it's what lets a contact adhesive or double-sided tape hold parts together immediately, well before the adhesive has chemically cured.
High tack means a strong initial grip on contact, which matters most for vertical or overhead applications where a joint needs to hold its own weight before it's mechanically supported or clamped. Tack is a different property from final cured bond strength — a high-tack adhesive isn't necessarily the strongest once fully cured.
What Is a Take-Up Unit (Bearing Housing)?
A take-up unit is a housed bearing — the same insert-bearing principle as a Pillow Block or Flanged Bearing Unit — mounted in a frame that slides along a set of slotted rails, adjusted by a T-bolt or screw mechanism. It's specifically for tensioning: sliding the bearing (and the shaft, sprocket or pulley it carries) along its rails to take up slack in a belt, chain or conveyor run as it wears or stretches in service.
Read AIMS's full Pillow Block Bearing Guide: UCP, UCF, UCFL & Plummer →
Shop AIMS's range of bearing housings →
What Is a Taper Lock Bush?
A taper lock bush is a two-part tapered sleeve that mounts a pulley, sprocket or coupling onto a shaft by wedging together under bolt tension — the pulley bore and the bush both carry a matching 8° taper, so tightening the bolts draws the two tapers together and clamps the whole assembly onto the shaft without a separate keyway press-fit.
AIMS stocks the standard 1008 to 5050 series in both steel and cast iron, in metric and imperial bore sizes, which is what makes taper lock the preferred mounting method for standard, repeatable-removal industrial drives — the same bush size fits a range of shaft diameters within its series, and the pulley comes off cleanly for maintenance rather than requiring a press or heat to shift a straight bore. See Pilot Bore (Pulley Mounting) for the alternative approach used on non-standard shafts.
Read AIMS's full Pulley Types Guide →
Shop AIMS's range of pulleys & sheaves →
What Is a Tapered Roller Bearing?
A tapered roller bearing uses rollers that converge to a common apex point, which lets the bearing carry heavy combined radial and one-directional axial load efficiently. Because each bearing only reacts thrust one way, tapered roller bearings are always mounted in opposing pairs, and the pair needs an axial preload — or controlled clearance — set correctly at fitting, which is a large part of why they're a common source of comeback if fitted without checking that setting.
Read AIMS's full Rolling Bearings: Types, Selection, Fitting & Failure Guide →
Shop AIMS's range of tapered roller bearings →
What Is a Tautliner (Curtainsider)?
A tautliner (also called a curtainsider, from a rival brand name that's become the everyday term in some states) is a trailer with a rigid roof and floor but flexible, tensioned side curtains in place of solid walls — the curtains roll back for full-length side access during loading and unloading with a forklift, then tension back down to fully enclose the freight for transport. It's the dominant trailer type for general palletised freight in Australia, trading a small amount of structural rigidity against much faster loading and unloading than a fully enclosed van-body trailer.
What Is Teflon?
Teflon is DuPont's registered trademark for PTFE (polytetrafluoroethylene) — a low-friction, chemically inert plastic with outstanding resistance to almost all industrial chemicals and a very wide temperature range.
In everyday trade conversation "Teflon" and "PTFE" are used almost interchangeably, much like Kevlar® and aramid — Teflon is a specific brand of PTFE rather than a separate material. It's the same material behind thread-seal tape, non-stick coatings and PTFE dry lubricant spray.
Read AIMS's full Teflon (PTFE) Spray Guide →
Shop AIMS's range of adhesives, sealants & tapes →
What Is a Tek Screw (Self-Drilling Screw)?
A Tek screw is a self-drilling screw with a hardened, fluted drill-point tip that drills its own pilot hole and cuts its own mating thread in one continuous drive, eliminating the separate pre-drilling step a standard self-tapping screw needs.
Tek screws are rated by Series (3–4, 5–6, 12, 500), which defines the maximum steel thickness the drill point can penetrate before the threads engage — selecting too light a series for the job causes the drill point to stall and spin uselessly rather than drive through, so the practical rule is to measure the combined steel thickness, add a small margin, and select the series rated above that figure. AIMS's own guide also covers Type 17 screws — a fluted, auger-style tip variant that's the Australian standard for structural timber framing, reducing splitting risk in dense hardwoods.
Read AIMS's full Self Tapping Screws Guide → for Series ratings, point types and corrosion-class selection
Shop AIMS's range of self-drilling & sheet metal screws →
What Is a Telescoping Gauge?
A telescoping gauge is a bore-measuring tool with spring-loaded plungers that expand outward to contact the walls of a hole, are then locked in position, and are measured externally with a Micrometer — the standard, no-setting-master-needed way to measure an internal diameter that a caliper or micrometer can't reach directly. AIMS's own guide rates a skilled operator's accuracy at around ±0.005mm, dropping to about ±0.05mm for a new operator, across a typical working range of roughly 8–150mm — making it the affordable, general-purpose choice for occasional bore measurement, as distinct from a Bore Gauge's dial or three-point variants used for repeated, higher-precision production work.
Read AIMS's full Bore Gauge Types Guide → for telescoping gauge accuracy and technique
Shop AIMS's range of telescopic gauges →
What Is Tensile Strength? (Ultimate Tensile Strength / UTS)
Tensile strength (or ultimate tensile strength, UTS) is the maximum pulling (tensile) stress a material can withstand before it breaks, measured in megapascals (MPa). It's the headline number used to compare material and fastener strength — and it's directly encoded in metric bolt grade markings.
For a metric bolt, the first number in the grade (e.g. the "8" in grade 8.8) multiplied by 100 gives the tensile strength in MPa — so a grade 8.8 bolt has a tensile strength of about 800 MPa. AISI 1045 plain carbon steel has a tensile strength around 585 MPa, while AISI 4140 alloy steel reaches roughly 1,020 MPa at the same diameter — a good illustration of why alloying matters. Tensile strength on its own doesn't tell the whole story, though: see Yield Strength for the number that matters more for most working loads.
Read AIMS's full Bolt Grade Chart →
What Is a Terminal (Electrical)?
An electrical terminal is a fitting crimped, soldered or bolted onto the end of a conductor to allow it to be securely and safely connected to a device, terminal block or another conductor — common types include ring, spade (fork), blade and bootlace ferrule terminals, each suited to a different connection style and current rating. Matching the terminal's wire-gauge range and connection type to the job — rather than forcing an oversized or undersized terminal onto a crimp — is what keeps a termination electrically sound and mechanically secure over time.
Shop AIMS's range of terminals →
What Is a Thimble (Wire Rope)?
A wire rope thimble is a teardrop-shaped metal liner fitted inside a wire rope eye to protect the rope from the sharp bend radius it would otherwise take, spreading the load around a smooth curved surface instead of a tight kink. AIMS stocks thimbles in galvanised and G316 stainless to match the rope they're terminating, and correct fitting leaves a small amount of play so the thimble can self-centre before the Wire Rope Grip is torqued down.
What Is Thread Fit (Thread Tolerance)?
Thread fit (thread tolerance) describes how tightly or loosely a mating external and internal thread engage once both are manufactured to their permitted size range — governed in the metric system by ISO tolerance classes and in the imperial (Unified) system by Class 1A/1B, 2A/2B, 3A/3B Threads.
A looser fit assembles faster and tolerates minor damage, dirt or a light coating better; a tighter fit gives less play, better alignment and (up to a point) better fatigue performance, at the cost of needing cleaner, more precisely made threads to assemble at all. Thread fit is distinct from Allowance above — tolerance is the permitted range of variation, while allowance is a deliberate offset applied on top of it. *(General engineering fundamentals — no dedicated AIMS article for this term.)*
What Is Thread Pitch?
Thread pitch is the distance between two adjacent thread crests, measured parallel to the thread axis — in the metric system expressed directly in millimetres (an M10 × 1.5 bolt has 1.5 mm pitch); in the imperial system expressed instead as TPI (Threads Per Inch) below.
The same word "pitch" also describes belt/pulley spacing and gear tooth spacing in completely different contexts, so it always pays to be clear which "pitch" is meant. See Coarse Thread and Fine Thread above for how pitch choice affects assembly speed, strength and vibration resistance at a given nominal diameter.
Read AIMS's full Metric vs Imperial Fasteners Guide → for metric pitch and TPI examples side by side
What Is Thread Sealant? (Anaerobic Liquid)
Anaerobic liquid thread sealant cures between the threads of a pipe joint, filling the thread form completely for a leak-free seal that bonds to both surfaces — unlike PTFE (Thread Sealing) tape or Pipe Dope, neither of which bond to the metal.
That bonding gives it vibration resistance the other two can't match, and a genuine pressure rating: Loctite 567 seals metal pipe threads up to ¾" BSP to 690 bar, Loctite 577 covers larger fittings (¾" to 2" BSP) at the same pressure rating, and Loctite 569 is the polymer-safe formulation for parallel threads and plastic fittings.
Read AIMS's full Loctite Thread Sealant Guide and Thread Lock & Seal Guide →
Shop AIMS's range of Loctite adhesives & thread sealants →
What Do the Threadlocker Colour Grades Mean? (Purple, Blue, Red, Green)
Loctite threadlocker colours signal a strength tier, not a complete specification — always check the actual bolt size, removability and service temperature for the specific product rather than relying on colour alone.
Purple (Loctite 222) is low-strength, hand-tool removable, suited to small fasteners and fine-thread screws (roughly M2–M10 depending on the specific product) with a breakaway torque around 3–6 Nm on an M10 — think instruments, electronics, set screws and adjustment points. Blue (Loctite 242/243/248) is medium-strength and still hand-tool removable, covering fasteners up to M36 depending on grade, with a breakaway torque of roughly 15–20 Nm on an M10 — Loctite 243 is the most widely used threadlocker in industrial and maintenance work globally, and is oil-tolerant, unlike its predecessor 242 which needed a clean, dry surface. Red (Loctite 262/263/268/271/272/277) is high-strength and genuinely requires heat to remove — heating to at least 250°C and applying removal torque while still hot — covering the same general fastener range up to M36 (M100+ on the heavy-duty 277 grade), with breakaway torque around 40–60 Nm on an M10. Green (Loctite 290) is a medium-to-high-strength Wicking Grade threadlocker, applied after assembly rather than before, for fasteners discovered loose after the fact.
Read AIMS's full Loctite Threadlocker Guide and Thread Lock & Seal Guide →
Shop AIMS's range of threadlockers →
What Is a Three-Phase Fan/Heater Supply?
A three-phase fan/heater supply is 415V power delivered across three alternating current phases rather than one, and it's the supply required once a fan or heater's load outgrows what a Single-Phase Fan/Heater Supply can practically carry — generally from around 9 kW upward for heaters, or once a fan or cooler model crosses into its 415V-rated size class.
The practical threshold shows up clearly across AIMS's own cooling and heating equipment: HVLS fans of 5.5 m diameter and larger, mancoolers from around 900 mm blade diameter up, large industrial evaporative coolers, and diesel or gas heater fan systems above roughly 50 kW all step up to three-phase, where a smaller model in the same range sits comfortably on single-phase. It's a genuine specification constraint worth checking early — a workshop without an existing three-phase supply will need a licensed electrician to install one before a larger HVLS Fan, Mancooler or Indirect-Fired Diesel Heater can go in, which can be the deciding factor between stepping down to a single-phase model or budgeting for the electrical work.
Read AIMS's full Industrial Heating Guide and Industrial Cooling Guide →
Shop AIMS's range of HVAC & refrigeration equipment →
What Is a Three-Phase Motor?
A three-phase motor runs on Australia's 415V (line-to-line) three-phase supply, covering everything from 0.18 kW up to 315 kW and beyond — a much wider range than a Single-Phase Motor's practical ~2.2 kW ceiling, and the standard choice for compressors, larger pumps, conveyors, machine tools and HVAC equipment. Three-phase motors are inherently self-starting: the rotating magnetic field produced by three supply phases offset 120 degrees from each other generates its own starting torque directly, with no capacitor or auxiliary winding needed.
Where a three-phase supply is available on site, it's generally the better choice at any power level above the smallest loads — three-phase motors run more efficiently, start with more torque, run cooler and last longer under load than an equivalent single-phase motor. A missing or reversed supply phase is also a common, specific fault on three-phase equipment: a motor "humming but not starting" on three-phase almost always means one of the three supply phases is absent at the terminals (single-phasing), while a motor running in the wrong direction means two of the three supply phases are transposed.
Read AIMS's full Electric Motor Guide → for the full single-phase vs three-phase comparison table
Shop AIMS's range of electric motors →
What Is a Throttling Valve? (Flow Modulation)
A throttling valve is any valve designed to hold flow at a precise, stable intermediate setpoint — not just fully open or fully closed — with a Globe Valve the purpose-built default for this duty in most industrial systems.
The critical selection mistake this term exists to prevent is reaching for the wrong valve type to throttle: a standard Gate Valve or a bare Ball Valve run part-open will suffer cavitation and wire-drawing erosion within weeks to months, since neither was engineered for the high-velocity jet a partially-open gate or ball creates. Genuine throttling duty calls for a globe valve, a V-port ball valve, a butterfly valve fitted with a positioner, or a Diaphragm Valve — never a plain on/off valve pressed into service it wasn't rated for.
Read AIMS's full Globe Valve Guide →
What Is a Thrust Ball / Thrust Roller Bearing?
A thrust bearing is built to carry axial (Axial Load / Thrust Load) load only, with little to no radial capacity — the opposite emphasis to almost every other bearing in this list. Thrust ball bearings suit light-to-moderate axial load at moderate-to-high speed and lower cost; thrust roller bearings (cylindrical, tapered or spherical rolling elements) trade some speed capability for substantially higher axial load capacity.
As a rough speed guide from AIMS's own guide: any thrust type is fine up to about 500 RPM, ball or needle types are preferred from 500–2,000 RPM, ball is preferred above 2,000 RPM, and above 5,000 RPM a specialist precision-grade ball thrust bearing is needed. Many machines run a radial bearing (carrying the shaft's weight) and a thrust bearing (carrying the axial component) together on the same shaft, each doing the job the other can't.
Read AIMS's full Thrust Bearing Guide: Types, Sizes & Selection →
Shop AIMS's range of thrust bearings →
What Is TIG? (Tungsten Inert Gas Welding)
TIG — Tungsten Inert Gas — welding uses a non-consumable tungsten electrode to sustain the arc while the welder feeds a separate Filler Rod (TIG) into the Weld Pool / Puddle by hand, with pure argon Shielding Gas protecting both the tungsten and the molten metal from contamination. Unlike MIG, nothing feeds automatically — the welder controls the torch in one hand and the filler rod in the other, which is what makes TIG capable of the cleanest, most precise welds of any common process but also the slowest to learn. TIG is the everyday trade name for the process; its formal engineering designation is GTAW (Gas Tungsten Arc Welding) — the same process, two names.
Industry consensus puts genuine production-quality TIG technique at 6–12 months of regular practice, well beyond what MIG or stick welding demand. TIG runs DC electrode negative (DCEP / DCEN (Welding Polarity)) for steel, stainless and titanium, but switches to AC for aluminium and magnesium — the alternating current's positive half-cycle strips the tenacious aluminium oxide layer that would otherwise stop the weld from fusing. Tungsten choice matters too: see the Tungsten Electrode Colour Code (AWS A5.12) for which colour suits which job.
Read AIMS's full TIG Welding Guide and MIG vs TIG vs Stick Welding Guide →
Shop AIMS's range of TIG welding rods →
What Is a Timing Belt?
Timing belt is the everyday name for what's technically a synchronous belt — a toothed, positive-engagement belt with no slip, used wherever a driven shaft needs to stay in an exact phase relationship with its driver, from automotive camshaft timing to indexing machinery.
See Synchronous (Timing) Belt for the full technical entry — the two terms describe exactly the same component, with "timing belt" the common trade and consumer term and "synchronous belt" the term more likely to appear in an engineering specification.
Shop AIMS's range of industrial drive & conveyor belts →
What Are Tin Snips? (Aviation Snips)
Tin snips are hand shears purpose-built for cutting sheet metal — a scissor-action tool with hardened, serrated jaws that shear rather than tear through material a standard pair of scissors would just crumple.
Aviation snips are colour-coded by cutting direction so the right pair is easy to grab on sight: red cuts left curves, green cuts right curves, and yellow cuts straight lines — a system that lets a tradesperson follow a curved cut-line accurately rather than fighting the tool's natural cutting arc. See Cold Chisel for the equivalent hand tool for cutting or shearing thicker, non-sheet metal stock.
Read AIMS's full Tin Snips & Aviation Snips Guide →
Shop AIMS's range of snips & shears →
What Is Titanium?
Titanium is a lightweight metal with an exceptional strength-to-weight ratio and outstanding corrosion resistance — it forms a stable, self-healing oxide layer on its surface, giving it resistance to seawater and most industrial chemicals that even 316 stainless steel eventually succumbs to over long exposure.
Grade 2 (commercially pure titanium) is the general-purpose grade, chosen for its corrosion resistance and good weldability in marine, chemical-processing and medical-implant applications; Grade 5 (Ti-6Al-4V, an aluminium-vanadium alloy) trades some of that corrosion resistance for significantly higher strength, and is the grade behind most aerospace, motorsport and high-performance fastener applications. The trade-off holding titanium back from wider industrial use is cost — raw material and machining costs both run well above stainless steel — so it's specified only where the weight saving or corrosion performance genuinely justifies the premium, rather than as a general-purpose upgrade. See Stainless Steel and Duplex Stainless Steel for the more commonly specified corrosion-resistant alternatives at a fraction of the cost.
What Is a Toggle Clamp?
A toggle clamp uses an over-centre lever mechanism to lock a workpiece firmly in place with a single, fast hand or foot motion — push the handle down past its over-centre point and the clamp locks under spring tension, with no screw to wind and no separate locking step.
Toggle clamps are the standard workholding choice on jigs, fixtures and production tooling — welding jigs, drill jigs and assembly fixtures — precisely because that single-motion lock-and-release action lets an operator load, clamp, work and unload a part far faster than a screw-driven clamp would allow across a repetitive job.
What Is Tolerance?
Tolerance is the permitted range of variation around a part's nominal (stated) dimension — the acceptable "plus or minus" a manufactured part can fall within and still be considered correct, since no manufacturing process produces a perfectly exact dimension on every single part. On a drawing, tolerance is expressed either as a simple ± figure, or — for a fit between two mating parts — as an ISO 286 class code such as H7 or h6. Where the requirement is about a feature's shape, orientation or position rather than just its size, GD&T tolerancing takes over from a plain ± figure. However it's expressed, tolerance is what a GO / NO-GO Gauge or other inspection method is actually checking a part against on the shop floor.
Read AIMS's full GD&T Symbol Cheat Sheet → for how geometric tolerancing extends beyond a simple ± figure
What Is a Tool?
A tool is any device or implement used to carry out physical work — cutting, shaping, fastening, measuring, holding or otherwise acting on a workpiece or material — ranging from a simple hand tool through to a complex powered machine.
It's used here in the broad, umbrella sense: AIMS's own range spans hand tools, cutting tools, power tool accessories and workholding equipment, each with its own dedicated glossary coverage elsewhere on this page — this entry exists to anchor the general term itself, not to replace those more specific ones. In everyday trade speech "tool" also gets used loosely for machine attachments (a "cutting tool" on a lathe) and even for software or business processes (a "planning tool"), so context always matters more than the bare word.
What Is a Toolholder?
A toolholder is the steel body that mounts to a machine's spindle or turret and provides a rigid, precisely located mounting point for an Indexable Insert — the holder is the long-term investment, expected to last for years, while the insert itself is a routinely replaced consumable. Matching the toolholder's geometry (its own ISO-coded designation, separate from the insert's own ISO 1832 Insert Code) to the insert it carries, and to the actual cutting operation being performed, is what keeps an indexable tooling setup both rigid and cost-effective — a mismatched or worn holder undermines even a premium, correctly-chosen insert.
Read AIMS's full Indexable Insert Guide → for how the toolholder and insert work together
Shop AIMS's range of indexable turning tool holders →
What Is Top Width? (Belt Sizing)
Top width is the measurement across the top face of a V-belt or wedge belt — for example 11 mm, 13 mm or 20 mm — and it's a key sizing dimension distinct from Datum Length, used especially in heavy fleet and truck fan-belt selection under 11A/13A/20A-style designations.
Getting top width right matters independently of getting datum length right: two belts can share the same datum length but a different top width, and a belt with the wrong top width for its sheave groove won't seat and wedge correctly even if the length is otherwise a perfect match.
What Is Torque (Fastener Context)?
Torque is the rotational force applied to a fastener during tightening, measured in newton-metres (Nm) or, in imperial units, pound-feet (lb-ft) or inch-pounds (in-lb) — the input value a torque wrench controls, as distinct from Clamp Force above, which is the actual functional result tightening is trying to achieve.
For an M10 bolt, AIMS's own torque chart shows dry-thread torque ranging from around 20 Nm at Grade 4.6 up to around 84 Nm at Grade 12.9 — a more than fourfold difference for the identical bolt size, purely because of grade. Getting torque wrong in either direction causes real failures: under-torquing risks progressive loosening under vibration, while over-torquing stretches the bolt past its yield point (see Proof Load), permanently reducing the clamp force it can ever deliver again.
Read AIMS's full Metric Bolt Torque Chart → for torque values by size and grade
Shop AIMS's range of torque wrenches & screwdrivers →
What Is Torsional Strength?
Torsional strength is the maximum twisting (rotational shear) load a fastener can withstand about its own axis before failing — most relevant to installation, where a fastener can be over-tightened past its torsional limit and its head or drive recess can shear off, even though the thread and shank underneath remain intact and undamaged.
This is a distinct failure mode from tensile failure (the bolt stretching and necking under axial pull) or shear failure (the shank being cut across by a perpendicular load) — a "twisted-off" head is specifically a torsional failure, common with self-tapping and self-drilling screws driven with an impact driver, and with smaller socket-head fasteners over-torqued through an undersized or worn Allen key. *(General engineering fundamentals, cross-referenced against AIMS's own self-tapping screw and Allen key guides — no single dedicated AIMS article on torsional strength itself.)*
What Is Toughness?
Toughness is a material's ability to absorb energy and resist fracture under sudden impact or shock loading — it's a different property from Tensile Strength / Ultimate Tensile Strength, which measures resistance to steady pulling force, and different again from Hardenability.
A very hard, high-tensile material isn't automatically tough — grade 12.9 bolts are a good example: they're stronger than grade 8.8 but noticeably less tough, meaning they can fail suddenly under shock or impact loading where a grade 8.8 bolt would yield and give warning first. This is exactly why AIMS's own bolt grade guidance recommends caution using 12.9 in dynamic, shock-loaded applications despite its higher rated strength.
Read AIMS's full Bolt Grade Chart →
What Is TPI? (Threads Per Inch)
TPI (Threads Per Inch) is the imperial-system measure of thread pitch — a straight count of how many complete threads occur within one inch of length — used in place of the metric millimetre-pitch figure on UNC, UNF, BSW and BSF threads.
A 3/8"-16 UNC bolt has 16 threads per inch; its finer-pitch UNF equivalent, 3/8"-24, packs 24 threads into the same inch. Because TPI and metric pitch describe the same underlying property in different units, they can be converted between each other but a bolt cut to one system will never mate with a nut cut to the other — see Coarse Thread and Fine Thread above for the practical consequences of getting pitch selection wrong.
Read AIMS's full Metric to Imperial Fastener Conversion Chart → for TPI-to-metric-pitch conversion across all common sizes
What Is Traceability (Calibration)?
Traceability, in a calibration context, means an instrument's calibration record connects back through an unbroken chain to a recognised national measurement standard — in Australia, the National Measurement Institute (NMI), or an equivalent overseas body. It's not optional paperwork: calibration records must be traceable for a business to hold ISO 9001 or AS/NZS ISO 9001 certification, and a measuring instrument used past its calibration due date invalidates the traceability of every measurement that was taken with it in the meantime — not just the ones taken after the due date passed. NATA-accredited laboratories are the ones that issue calibration certificates carrying this traceability in a form that will actually stand up to an audit.
Read AIMS's full guide to calibration intervals → for what a traceable calibration record needs to show
What Is a Transfer Point? (Conveyor)
A transfer point is the location where bulk material moves off one conveyor belt and onto the next — or into a chute, bin or process vessel — via a transfer chute that redirects and settles the material stream onto the receiving belt.
It's the single highest-wear, highest-risk zone on most bulk material handling systems: material free-falls and impacts the receiving belt here, generating the dust, spillage and belt damage that Skirting (Skirt Board, Conveyor), impact-rated Troughing Idler sets and a properly positioned Belt Scraper (Conveyor Cleaner) are all specified to control. A well-designed transfer point matches chute geometry and drop height to the material's characteristics (particle size, moisture, friability) to load the belt centrally and gently rather than letting material free-fall directly onto it — getting this wrong is one of the most common root causes of the Belt Tracking (Conveyor) problems and premature Cover Compound (Conveyor Belt) wear that show up further down the line.
What Is Tridon? (AU Hose Clamp Brand)
Tridon is a hose clamp brand so widely used in Australian trade conversation that its name is often used almost generically for a worm-drive hose clamp, the same way "Nyloc®" and "Molly" are used for their respective fastener types — but it's a genuine, separate brand name, not a trademark AIMS carries.
AIMS's own Hose Clamp Guide identifies Tridon as the dominant Australian brand for worm-drive clamps, but AIMS instead stocks Champion, Inox World, Dixon and GJ Works as trade-tier equivalents — genuinely comparable products under different brand names, not inferior substitutes. Worm-drive is one of four common hose clamp types; see the guide below for how it compares to T-bolt, spring and ear-style clamps for a given application.
Read AIMS's full Hose Clamp Guide →
What Is Triplex Roller Chain?
Triplex roller chain runs three strands of roller chain side by side on the same pitch and sprocket, giving roughly 2.5× the load capacity of Simplex Roller Chain — the highest-capacity standard multi-strand option, ahead of Duplex Roller Chain.
Choosing triplex over a larger single-strand pitch keeps the sprocket diameter and overall drive geometry more compact for a given load rating, which matters where space around the drive is tight. See Roller Chain Anatomy for what each individual strand is actually built from.
Read AIMS's full Roller Chain Guide →
Shop AIMS's range of chain & sprockets →
What Is a Trolley? (Material Handling)
A trolley, in a material-handling sense, is a wheeled platform or frame used to move loads by hand around a workshop or warehouse floor — distinct from a Beam Trolley, which runs on an overhead beam as part of a lifting system rather than rolling on the floor.
Platform trolleys and sack (hand) trucks cover most general material-moving needs, fitted with Castor wheels sized and rated to the loads they'll carry — the right trolley for a job comes down to load capacity, floor surface, and whether the load needs to be tipped and rolled (a sack truck) or carried flat (a platform trolley).
Read AIMS's full Hand Truck & Sack Truck Guide →
Shop AIMS's range of material handling & storage — trolleys, shelving →
What Is a Troughing Idler?
A troughing idler is a set of angled support rollers — typically three rollers, a flat centre roller flanked by two inclined side rollers — mounted under the loaded (carrying) side of a belt conveyor to shape the flat belt into a shallow trough. Troughing the belt this way lets it carry significantly more bulk material for a given width than a flat belt could, using the belt's own edges to help contain the load rather than relying on Skirting (Skirt Board, Conveyor) alone.
Standard troughing angles are 20°, 35° and 45° from horizontal, with 35° the most common general-purpose choice, and idler spacing is typically 1.0–1.5 m along the main run, roughly halved through loading zones where impact loading is highest. On the empty (return) side, the belt runs on simple flat return idlers rather than troughing sets, since there's no material load to contain. Troughing and return idler selection and dimensions are governed internationally by the CEMA 502 standard. See Belt Tracking (Conveyor) for how idlers are also used to keep the belt centred, and Transfer Point (Conveyor) for where impact-rated idlers matter most.
What Is a Trubolt®? (Ramset Trademark — Wedge Anchor)
Trubolt® is Ramset's separate, heavier-duty wedge/stud anchor line — Ramset itself describes it as a true-to-size, heavy-duty, torque-controlled expansion anchor built with an anti-rotation expansion sleeve, positioned above Dynabolt® above in Ramset's own product range for more demanding structural anchoring work.
It's worth being precise here, since the two names get used interchangeably on-site far more often than they should: Trubolt® and Dynabolt® are both Ramset-trademarked wedge/sleeve-style expansion anchors sitting inside the generic Wedge Anchor category — not two different anchoring mechanisms — but they're two separate, non-interchangeable Ramset product lines, not one rebadged as the other. Trubolt® is the heavier-duty, structural-grade line and Dynabolt® the general-purpose trade line; the right call is to check the specific product's load rating and AS 5216 ETA approval for the job rather than assume "Trubolt vs Dynabolt" is just a naming difference.
Read AIMS's full Concrete Anchor Guide → for AIMS-stocked heavy-duty wedge anchor equivalents
Shop AIMS's range of stud anchors →
What Is a Truss Head Screw?
A truss head (also called mushroom or oven head) is a wide, very flat, low dome designed to maximise bearing area while minimising overall head height — the right choice for thin sheet metal and soft materials, though it carries a lower torque rating than a cap or pan head and shouldn't be used for high-torque joints, unlike the taller, more proud Dome Head.
It sits within AIMS's broader screw-head-type family alongside pan, button, countersunk and bugle heads — see Flat Head below for the countersunk variant, and AIMS's own guide for the full comparison across all common head shapes.
Read AIMS's full Screw Head Types Guide → for the complete head-shape and drive-type comparison
What Is a Tube Threaded Insert?
A tube threaded insert is a threaded fitting installed into the open end of a hollow tube or profile — pressed, welded or adhesive-bonded in — to create a usable threaded mounting point on material that's otherwise too thin-walled to tap directly.
It's very often installed specifically to give a hollow-section frame leg somewhere to thread a Levelling Foot into, since the tube wall itself is almost always too thin to hold a useful thread directly. *(General engineering/hardware terminology — no dedicated AIMS article for this term specifically.)*
What Is Tungsten Electrode Colour Code? (AWS A5.12)
The tungsten electrode colour code is a system of coloured bands painted on one end of a TIG electrode to identify its alloy content at a glance, set out in AWS A5.12M/A5.12 (the American Welding Society's tungsten electrode specification, adopted in Australia under AS/NZS 1167.5). Rather than reading a stamped part number under workshop lighting, a welder can identify the right electrode for the job by colour alone.
The core colours every Australian TIG welder should know: green is pure tungsten (EWP), the traditional choice for AC aluminium on older machines; red is 2% thoriated (EWTh-2), a strong DC performer for steel and stainless but mildly radioactive, which has pushed many workshops toward safer alternatives; grey is 2% ceriated (EWCe-2), a solid non-radioactive DC option for lower-amperage and thin-section work; gold is 1.5% lanthanated (EWLa-1.5), widely regarded as the best single all-rounder for welders who move between AC and DC work; and purple is a modern rare-earth blend (EWG/E3), a non-radioactive substitute for thoriated tungsten. Zirconiated grades (brown and white bands) round out the AC-only end of the range, favoured for maximum weld purity on aluminium. Getting this right matters — the wrong tungsten is a common, avoidable cause of arc instability and contaminated welds in TIG (Welding).
Read AIMS's full TIG Tungsten Electrode Guide and TIG Welding Guide →
Shop AIMS's range of TIG welding rods →
What Is a Turnbuckle?
A turnbuckle (also called a rigging screw) is a threaded tensioning device — a central body with two opposing threaded eyes, hooks or jaws — that's rotated to lengthen or shorten a Wire Rope, rod or cable run.
Turnbuckles are the standard way to tension guy wires, fencing wire and rigging lines on site, and to fine-tune a sling or stay's length after it's connected — turning the body draws the two end fittings together or apart without needing to shorten the wire rope itself. AIMS stocks jaw/jaw, eye/eye and hook/eye combinations to suit different end connections, in both drop-forged carbon steel (galvanised, for general rigging) and stainless steel (for marine or corrosive environments).
Two things matter more than they first appear: thread direction and mousing. A turnbuckle's two end fittings thread in opposite directions (one left-hand, one right-hand), which is what lets rotating the body alone draw both ends in or out symmetrically rather than needing to unscrew one end and rethread it. And once a turnbuckle is tensioned to its working length, it should be locked — either with its own lock nuts where fitted, or by Mousing the body to one of the end fittings — because vibration alone can walk an un-locked turnbuckle loose over time, which is a common cause of a guy wire or lashing gradually going slack rather than failing all at once.
Shop AIMS's range of turnbuckles →
What Is a Turntable (Semi-Trailer Coupling)?
A turntable is a fifth-wheel-style coupling mounted on the rear of a lead trailer — rather than on a Prime Mover's chassis — that lets a second semi-trailer's King Pin lock on directly behind it, forming the link in a B-Double or B-Triple combination. It does the same locking and articulation job as the prime mover's own fifth wheel coupling, just positioned further back in the combination.
What Is a Type 27 Disc Shape?
Type 27 is the flat-profile backing plate used on grinding and Flap Disc products, best suited to shallow working angles of roughly 0–15° for blending and finishing work — as opposed to the more aggressive Type 29 Disc Shape. Picking the wrong type for the angle you're actually working at is one of the more common reasons a disc wears unevenly or underperforms for its rated grit.
What Is a Type 29 Disc Shape?
Type 29 is a conical, dished backing-plate profile engineered for steeper working angles of roughly 15–35°, letting a Flap Disc bite in more aggressively for faster stock removal than the flatter Type 27 Disc Shape. Picking the wrong type for the angle you're actually working at is one of the more common reasons a disc wears unevenly or underperforms for its rated grit.
U
What Is a U-Bolt?
A U-bolt is a U-shaped threaded rod with threaded ends on both legs, used to clamp a round or square item — pipe, exhaust, leaf spring, conduit — against a flat mounting plate or bracket using two nuts.
U-bolts are sized by the inside diameter of the "U" (matching the pipe or round stock being clamped) plus the thread size and leg length of the threaded ends. They're a straightforward mechanical clamp rather than a precision fastener, so bolt grade matters less here than making sure the U-bolt's inside radius actually matches the item being clamped — an oversized U-bolt won't develop even clamp pressure around the full circumference.
Shop AIMS's range of fasteners →
What Do UNC / UNF / UNEF / UNJ / UNR / UNS Mean (Thread Series)?
UNC (Unified National Coarse) and UNF (Unified National Fine) are the two everyday imperial thread series governed by ANSI/ASME B1.1, differing only in pitch at a given nominal size — a 1/2"-13 UNC bolt has 13 TPI, while its 1/2"-20 UNF equivalent has 20 TPI, and the two are not interchangeable despite matching diameters.
The less common variants extend the same family for specific needs: UNEF (Unified National Extra Fine) packs even more threads per inch than UNF, for thin-walled parts and fine adjustment; UNJ adds a controlled root radius for improved fatigue resistance, used in aerospace fastener specifications; UNR specifies a rounded (rather than flat) root on standard UNC/UNF threads, again for fatigue improvement, without the tighter overall tolerance UNJ requires; and UNS (Unified National Special) covers any non-standard pitch/diameter combination that doesn't fit the coarse or fine series tables.
Read AIMS's full BSP vs NPT vs UNC Thread Standards Guide → for UNC/UNF sizing tables and common applications
What Is a Universal Beam (UB)?
A universal beam (UB) has a narrower flange relative to its depth, optimised to resist bending loads along its length — the standard structural-steel choice for horizontal spans, as distinct from the more evenly balanced Universal Column section used for vertical supports. It matters to rigging because a Beam Trolley or Girder Clamp's flange width needs to be measured against the actual beam profile in use, not assumed from whether it's called a "beam" or a "column" on the drawing.
What Is a Universal Column (UC)?
A universal column (UC) has a flange width closer to its overall depth than a Universal Beam, giving a more evenly balanced section better suited to carrying compressive (axial) load — the standard structural-steel choice for vertical supports, as opposed to a UB's horizontal-span role. It matters to rigging because a Beam Trolley or Girder Clamp's flange width needs to be measured against the actual column profile in use, not assumed from whether it's called a "beam" or a "column" on the drawing.
What Is UOM? (Unit of Measure)
UOM stands for Unit of Measure — the specific quantity a product is counted, ordered and priced in, such as each, pair, box, metre, kilogram, litre or pack of 100.
Getting the UOM right matters more than it sounds: ordering "10" of a fastener sold by the box of 100 is a very different order to "10" of the same fastener sold individually, and mismatched UOMs between a customer's purchase order and a supplier's SKU listing are one of the most common causes of order errors in trade and industrial procurement. Consistent UOM data underpins accurate Inventory counts and pricing across a large catalogue.
What Is Upset? (Rivet Installation)
Upset describes the deliberate deformation — a localised thickening or bulging — of a rivet's tail or a fastener's end during installation, forming the second head (or the blind-side clamping bulge) that actually completes the joint.
On a solid rivet, upsetting is done by striking or pressing the protruding tail against a bucking bar on the opposite side, spreading the metal outward into a second head. On a blind rivet or rivet nut, the same underlying idea happens as the mandrel is pulled — the body is forced to upset (bulge) on the hidden side rather than being struck directly. Either way, "upset" describes the metal being deliberately displaced to form the mechanical lock, not a fault or defect. *(General fastening-industry terminology, cross-referenced against AIMS's own rivets guide.)*
What Is a Utility Knife? (Stanley® Knife)
A utility knife — commonly called a Stanley® knife in Australian trade usage, after the long-running Stanley Works brand — is a handheld cutting tool with a replaceable, retractable blade, used for cutting cardboard, packaging, plastic sheet, insulation and general light-duty trade cutting.
Blade style is the main practical choice: a standard straight blade suits general-purpose cutting, while a hook blade is purpose-built for cutting materials like carpet, vinyl and roofing membrane where a straight blade risks slicing into what's underneath. Most trade utility knives are now auto-retracting or otherwise safety-engineered, since an exposed fixed blade left extended is a genuine and common cause of hand injury — a real reason to specify a safety-retracting model over a cheaper fixed-blade knife for regular trade use.
Read AIMS's full Utility Knife Guide →
V
What Is a V Block? (Vee Block)
A V block is a rectangular metal block with a precision-ground V-shaped groove across one or more faces, used to hold round or cylindrical stock steady and on-centre for marking out, drilling or inspection — the V groove self-centres round stock far more accurately than trying to hold it flat.
V blocks are typically supplied and used in matched pairs, sometimes with a clamp that holds the workpiece down into the V, and are a standard fixture in any workshop doing precision marking-out or drilling on round bar, shafts or tube.
Shop the Maxigear vee blocks and clamp set →
What Is a V-Belt? (Drive Belt)
A V-belt — also called a drive belt — is a rubber power-transmission belt with a trapezoidal (V-shaped) cross-section, designed to wedge into a matching pulley groove and transfer rotational power from a motor to a driven component through friction rather than teeth.
The V-shape is what makes it grip better than a flat belt: it self-centres in the groove, resists lateral movement, and the wedging action multiplies friction under load without needing extra tension to prevent slip. A well-maintained V-belt runs for thousands of hours, but its actual service life depends heavily on correct tensioning, accurate pulley alignment and routine inspection for cracking or fraying — see Belt Tensioner and Belt Tension Gauge for how that's checked and maintained in practice. Common construction variants include the Wrapped V-Belt (Fabric-Covered), the Raw-Edge / Cogged V-Belt, and the everyday automotive Fan Belt.
Read AIMS's full V-Belt & How It Works guide and V-Belt Sizing & Identification Guide →
Shop AIMS's range of industrial drive & conveyor belts →
What Are the V-Belt Profiles? (SPZ/SPA/SPB/SPC, Classical A/B/C/D)
V-belt profile is the belt's cross-sectional shape and size, and Australian industrial supply runs two separate, non-interchangeable families: classical (Z, A, B, C, D, E, using a 40° wedge angle) and metric narrow-section (SPZ, SPA, SPB, SPC, using a steeper 34° angle for higher power density in a smaller cross-section).
The critical trap is that a classical and a narrow belt can share the same top width and still not interchange — SPB and B-section are both 17 mm wide, but SPB is 3 mm deeper, and the different wedge angles mean neither seats correctly in the other's groove. Practical sizing reference, all figures in PCD (Pitch Circle Diameter) rather than outside diameter: A-section needs a minimum 75 mm PCD sheave (100 mm recommended), B-section 125 mm (150 mm recommended), C-section 175 mm (200 mm recommended); SPZ needs 63 mm minimum (80 mm recommended), SPA 90 mm (112 mm recommended), SPB 140 mm (180 mm recommended). Narrow (SP) belts carry up to three times the power of a classical belt of similar width, due to the deeper wedging action, but require SP-specific sheaves — you can't retrofit a classical sheave with a narrow belt to gain the extra capacity. See Belt Length Notation (La/Le/Ld/Lp/Lw/Li) and Belt Cross-Reference (Interchange) for how a specific belt within a profile is then ordered.
Read AIMS's full V-Belt Sizing & Identification Guide →
Shop AIMS's range of V-pulleys and heavy-duty drive belts (ISO 4184) →
What Is a Variable Pitch Pulley?
A variable pitch pulley has a groove width that can be mechanically adjusted, changing the effective pitch diameter the belt rides on and altering the drive's speed ratio — but only while the drive is stopped, not continuously during operation.
This is a common misunderstanding worth correcting directly: a variable pitch pulley is not infinitely or continuously variable while running. The groove is adjusted, then locked in place for that speed setting; for genuine continuous variable speed control during operation, a Variable Frequency Drive (VFD) on the motor is the correct solution, not a variable pitch pulley. See Pulley and Sheave for the broader category this component sits within.
Read AIMS's full Pulley Types Guide →
Shop AIMS's range of pulleys & sheaves →
What Is a Vernier Caliper?
A vernier caliper uses two scales — a fixed main scale and a sliding vernier scale — to resolve measurements far finer than the unaided eye could read from a plain ruler, subdividing the main scale's divisions down to 0.05mm or 0.02mm depending on the design. It measures four distinct dimensions on one tool: outside diameter or width (lower external jaws — shafts, fasteners, bar stock), inside diameter (upper knife-edged jaws — bores and grooves), depth (via a thin rod extending from the body) and step or shoulder height (using the jaws' back faces). Typical accuracy runs ±0.02–0.05mm. Its defining advantage over a Digital Caliper is having no battery and no electronics to fail — the reason it remains the preferred instrument in a wet, oily or coolant-rich environment where a digital caliper's electronics are a genuine liability, even though it's slower to read and demands a careful, parallax-free technique a digital or Dial Caliper doesn't.
Read AIMS's full Vernier Caliper Guide → for how to read the vernier scale and choose between the three caliper types
Shop AIMS's range of vernier calipers →
What Is a VFD (Variable Frequency Drive)?
A VFD (Variable Frequency Drive) converts incoming AC supply to DC, then back to AC at a controlled, variable frequency — which means it controls a motor's speed continuously, during both starting and running, not just the start like DOL (Direct-On-Line) Starting, Star-Delta (Y-Δ) Starting or a Soft Starter. This gives the gentlest start of the four common methods (typically 1.0–1.5 times FLA) and is the only one of the four offering genuine speed control — but it's also the most expensive and the most complex to install, needing consideration of electromagnetic compatibility and harmonics rather than a straightforward bolt-in.
A VFD is only worth the extra cost where variable speed is genuinely needed — for a fixed-speed load, a Soft Starter does the gentle-start job for less. Where it is needed, the payoff can be significant: on a variable-torque load like a fan or pump, running at reduced speed cuts power consumption disproportionately more than the speed reduction itself, which is a real energy saving beyond just the smoother start. A standard TEFC motor (see Motor Enclosure Type) can generally run on a VFD down to about 25–30Hz before its own cooling fan becomes ineffective; sustained operation below that calls for a separately-ventilated or TENV motor instead.
Read AIMS's full Motor Starting Methods Guide → for the full four-method comparison
Shop AIMS's range of Invertek variable frequency drives →
What Is VG? (Viscosity Grade)
VG stands for viscosity grade — the ISO classification system for industrial lubricating oils, based on the oil's kinematic viscosity at 40°C (ISO VG 32, 46, 68, 100 and so on, each number roughly the oil's viscosity in centistokes at that temperature). It's a genuinely different sense of "grade" from NLGI Grade (which classifies grease consistency, not oil viscosity) or fastener property class grade — worth keeping distinct rather than assuming "grade" means the same thing across AIMS's catalogue, per the existing Grade disambiguation note in this glossary.
What Is VHM (Solid Carbide)?
VHM (from the German *Vollhartmetall*, "solid hard metal") is the common trade term for a solid tungsten carbide cutting tool — carbide sintered with a cobalt binder throughout the entire tool body, rather than only at a brazed or clamped cutting tip. Solid carbide tools run at roughly 1,400 HV, genuinely hard enough for hardened steel and sustained production-volume work, and hold that hardness at cutting temperatures upwards of 900°C — but that same hardness comes with real brittleness, meaning a solid carbide tool demands a rigid machine setup and continuous, stable cutting, and is a poor fit for variable hobby-workshop conditions where a tougher HSS-Co tool's lower cost-per-part actually wins out. See ISO 513 K-Grade Carbide Classification above for how a specific carbide grade within the VHM family is chosen for a given workpiece material.
Read AIMS's full Cutting Tool Materials Guide → for the full hardness/toughness comparison against HSS and the ultra-hard materials
Shop AIMS's range of end mills & milling cutters →
What Is Vickers Hardness (HV)?
Vickers hardness (HV) measures the diagonal lengths of a square indentation left by a diamond pyramid indenter (136° included angle), pressed in under loads ranging from 5–120 kgf at macro scale down to as little as 0.01–1 kgf at micro scale — hardness is then calculated as 1.854 × load ÷ diagonal². That very fine load range is what makes Vickers the right scale for thin sections, case-hardened surface layers, individual metallurgical phases, and microhardness traverses across a weld — jobs where Brinell's heavy load or even Rockwell's indenter would be too coarse to give a meaningful, localised reading. It's tested in Australia under AS 1817 (aligned to ISO 6507-1 and ASTM E92/E384). See HV above for the separate, unrelated electrical meaning of the same two letters.
Read AIMS's full Hardness Testing Guide → for load ranges and material applications across all four hardness scales
What Is Vinyl Ester Resin? (Chemical Anchor)
Vinyl ester resin is the mid-tier resin chemistry used in Chemical Anchor systems, sitting between economy polyester resin and premium Epoxy Resin — it cures fast, tolerates a damp or imperfectly cleaned borehole better than epoxy does, and is the default resin specified for general structural anchoring in Australian trade.
The trade-off against epoxy is mostly about the top end of performance rather than everyday reliability: vinyl ester gives up a little maximum load capacity and chemical/temperature resistance compared with pure epoxy, in exchange for a faster cure and more forgiving installation conditions — exactly why it's the resin most commonly reached for on general fixing and retrofit work, while epoxy gets specified where an engineer needs the extra load headroom or the anchor faces sustained high temperature or aggressive chemical exposure. AIMS's chemical anchor guide sets out cure-time curves for vinyl ester from +5°C through +40°C.
Read AIMS's full Chemical Anchor Guide → for the full resin chemistry comparison and cure-time tables
What Is Vise-Grip®? (Locking Pliers)
Vise-Grip is the original trademarked brand of locking pliers — pliers with a toggle-lock jaw mechanism that clamps onto a workpiece or fastener and holds under its own spring tension, freeing both of the user's hands once it's set.
The name was originally Petersen Manufacturing's trademark (DeWitt, Nebraska, 1924, inventor William Petersen), now owned by Irwin, itself part of Stanley Black & Decker — but AIMS's own research found it's become genericised the same way Dynabolt® has for sleeve anchors: "Vise-Grip" is used in everyday trade conversation to mean the whole locking-pliers category, not just the genuine Irwin product. AIMS doesn't stock genuine Irwin Vise-Grip, selling Lockjaw, Stahlwille, Strong Hand and Excision GripLox equivalents instead — see Locking Pliers (Generic) for the underlying tool type and its jaw variants.
Read AIMS's full Locking Pliers Guide →
What Is Viton®? (FKM)
Viton is a well-known trade name (originally Chemours/DuPont) for FKM — fluoroelastomer — a high-performance synthetic rubber with excellent resistance to oils, fuels and a wide range of aggressive chemicals, and a usable temperature range of roughly -20°C to +200°C.
FKM costs noticeably more than NBR (Nitrile Rubber) — typically five to seven times as much — so it's specified only where NBR or EPDM (Ethylene Propylene Diene Monomer) genuinely can't handle the chemical or temperature exposure, such as aviation fuel systems, aggressive chemical service and high-temperature sealing. It's available in AIMS's range as O-rings and seals, and as a chemical-resistant glove material for handling aggressive solvents.
Read AIMS's full O-Ring Guide →
Shop AIMS's range of oil seals & O-rings →
What Is a Voltage Tester?
A voltage tester is a handheld device — contact or non-contact — used to check whether a circuit or conductor is live before starting electrical work. A non-contact tester (often called a "volt stick") detects the electrical field through the insulation without needing to touch a bare conductor, making it a fast first-pass safety check; a contact-type tester or multimeter should still confirm the result before work begins, since a non-contact tester can give a false reading if its battery is flat.
Any tester used for live work also carries a CAT rating (CAT I through CAT IV), which describes where in an installation it's safe to use — not how "good" the tester is. CAT II covers general power outlets and plug-in equipment; CAT III covers fixed wiring in distribution boards, switchboards and industrial equipment; CAT IV covers the point of supply itself, such as the main service entry or meter. A tester rated for a lower category used further upstream than it's rated for is a genuine safety risk, not just a technicality — the rating reflects the transient energy the tester is built to survive if something goes wrong at that point in the system, so matching the CAT rating to the job is as important as matching the voltage range.
Shop AIMS's range of voltage testers →
W
What Is Water Hammer?
Water hammer is the pressure surge and audible bang that occurs when a moving column of fluid is stopped abruptly — most often by a valve disc slamming shut under sudden flow reversal, or by a pump stopping suddenly with high static head downstream.
The risk is highest with sudden pump shutdown, high downstream static head, parallel pump systems, long discharge piping, or a single-plate swing Check Valve without a spring to close it ahead of full reverse-flow velocity — which is exactly why the dual-plate (wafer) check valve, closing faster and more controllably, has become the default modern choice for pump-discharge applications specifically to reduce this risk. Left unaddressed, repeated water hammer events fatigue pipe joints, fittings and valve seats well before their rated service life, showing up as an intermittent, hard-to-diagnose leak long before anyone connects it back to the original pressure surge.
Read AIMS's full Check Valve Guide →
What Is WaterMark Certification?
WaterMark is the ABCB-administered certification scheme confirming a plumbing product has been independently tested and certified fit for purpose under the Plumbing Code of Australia — mandatory for products installed in Australian drinking-water supply, hot and cold water installations, and water treatment infrastructure.
Getting WaterMark generally requires the product to already meet AS/NZS 4020 (testing for leachability, taste, odour, microbial growth and chemical extraction into drinking water) as a prerequisite standard, and for a metal valve, DR/DZR (dezincification-resistant) brass or an equivalent corrosion-resistant material as well — a standard, non-WaterMark brass valve is not a compliant substitute in potable water service, however similar it looks on the shelf.
Read AIMS's full Gate Valve Guide and Ball Valve Guide →
What Is WD-40®?
WD-40® is a multi-purpose water-displacing spray — the name stands for Water Displacement, 40th formula, referencing the 40 attempts it took chemist Norm Larsen to get the formula right at San Diego's Rocket Chemical Company in 1953, where it was originally developed as a rust-prevention and degreasing treatment for the aerospace industry (Convair used it to protect the Atlas missile from corrosion). It's since become one of the most recognised brand names in any workshop, to the point where the name is often used generically for light multi-purpose sprays the way Nyloc® or Molly are used for their fastener types.
Functionally, WD-40® sits closer to Penetrating Oil than a true lubricant — AIMS's own guide describes it as "primarily a water-displacement fluid and light penetrating oil" with a "modest surfactant formulation compared to dedicated penetrants," which is exactly why it's excellent for driving out moisture and light corrosion prevention but is outperformed by a purpose-built penetrant such as INOX MX3 or CRC 5-56 on a genuinely seized fastener, and shouldn't be relied on as a long-term lubricant the way a proper Grease would be.
Read AIMS's full WD-40 FAQ →
Shop AIMS's range of WD-40® →
What Is a Web Disc (Contour Disc)?
A web disc is a non-woven abrasive disc, made from the same style of synthetic-fibre-and-mineral material as a Scotch-Brite® pad, designed to flex and conform to a contoured or irregular surface for blending and finishing without gouging the way a rigid coated or bonded abrasive can on a curved profile.
Read AIMS's full Non-Woven Abrasive Pad & Disc Guide → for the full range of non-woven formats and grades.
What Is a Wedge Anchor? (Mechanical Expansion Anchor)
A wedge anchor is the generic engineering term for a mechanical anchor that expands a conical wedge, clip or sleeve against the sides of a pre-drilled hole in solid concrete as its nut is tightened, gripping the hole by friction and mechanical interlock rather than by chemical bond — a torque-controlled anchor, set and verified by feel and torque rather than by resin cure time.
Wedge anchors are rated for solid concrete only, not hollow brick or block, and AS 5216-qualified products carry ETA ratings that distinguish cracked-concrete from uncracked-concrete performance. The genericised Australian trade name for this whole anchor family is Dynabolt® below, and Ramset's own separate, heavier-duty engineered line in the same wedge-anchor category is Trubolt® — both are specific trademarked products sitting inside this generic Wedge Anchor category, distinct in turn from Drop-In Anchor below, which expands flush and internally threaded rather than protruding as a stud.
Read AIMS's full Concrete Anchor Guide → for wedge anchor selection and AS 5216 ratings
Shop AIMS's range of stud anchors →
What Is a Weld Pool / Puddle?
The weld pool — also called the puddle — is the small area of molten base metal (and filler, where one's being added) sitting directly under the arc, which solidifies behind the torch or electrode as it moves along the joint to form the finished bead. Reading the weld pool correctly, in real time, is one of the core skills that separates a confident welder from a beginner in every process — MIG (Welding), TIG (Welding) and SMAW / MMA alike.
In TIG (Welding) especially, the pool's appearance is a direct, moment-to-moment readout of weld quality. A properly molten aluminium pool ready to accept filler looks shiny and fluid; a dull or granular pool signals insufficient heat or inadequate surface cleaning before it's too late to fix without stopping. On stainless steel, the weld's colour as it cools tells the same story from a different angle — silver or bright straw means good heat control, blue means heat is running high, and black means the joint has oxidised badly enough to be a genuine concern. Reading the puddle, not just the numbers on the machine, is what lets an experienced welder adjust travel speed and angle on the fly.
Read AIMS's full TIG Welding Guide →
What Is a Welding Blanket?
A welding blanket is a horizontal, heavy-duty protective fabric — chrome leather, treated fibreglass or silica cloth, depending on required heat resistance — draped over equipment, floors or nearby surfaces to catch spatter and sparks and protect what's underneath from heat damage during welding or cutting. It's a surface-protection tool rather than a barrier: it sits over or around the work, not between the arc and people standing nearby, which is the job of a Welding Curtain or Welding Screen instead.
Chrome leather blankets, rated to roughly 500°C continuous, are the workshop standard for typical MIG, stick and plasma spatter work; treated fibreglass steps up to around 800°C for heavier industrial welding, and silica fabric handles sustained molten-metal exposure up to nearly 1,000°C. Deploying a welding blanket (along with a curtain or screen where bystanders or nearby combustibles are a factor) is part of the physical screening duty required under AS 1674.1 — Welding Safety (Hot Work / Fire Precautions) — not an optional extra.
Read AIMS's full Welding Blankets & Curtains Guide (AS 1674.1 Hot Work) →
Shop AIMS's Bossweld leather welding blanket →
What Is a Welding Curtain?
A welding curtain is a vertical fabric barrier — usually chrome leather, fibreglass or a translucent flame-retardant material — hung on a fixed frame or mounting point to block UV and infrared arc radiation, protect bystanders from arc flash, and mark out a defined work zone. Unlike a Welding Blanket, which lies over surfaces to stop spatter damage, a curtain's job is standing between the arc and anyone nearby who isn't wearing welding-rated eye protection.
Where the work location doesn't move, a fixed-frame curtain is the simplest, cheapest solution; where the welder needs to relocate around a workshop or site, the same curtain material mounted on a wheeled metal frame becomes a Welding Screen instead — same protective fabric, different mounting, chosen for portability rather than a difference in what it protects against. Fire-retardant compliance for welding curtain material is tested to AS 1441.13 (the Australian standard) or the equivalent European EN 1598, and deploying a curtain to screen the work area is one of the explicit duties set out under AS 1674.1 — Welding Safety (Hot Work / Fire Precautions).
Read AIMS's full Welding Blankets & Curtains Guide (AS 1674.1 Hot Work) →
Shop AIMS's Bossweld welding curtain →
What Is a Welding Screen?
A welding screen is a mobile, self-supporting version of a Welding Curtain — the same UV/IR-blocking barrier fabric, mounted to a freestanding wheeled metal frame instead of a wall or fixed point, so it can be rolled to wherever the work actually is. It does the same job as a fixed curtain — blocking arc flash and radiation from reaching bystanders and defining a work zone — but suits workshops and sites where the welding location changes job to job rather than staying put.
The distinction from a curtain is really about mounting and portability rather than function: a fabrication shop with one permanent welding bay is well served by a fixed curtain, while a maintenance team moving between jobs across a site, or a workshop bay shared for other work between welding jobs, gets more use out of a wheeled screen that can be set up and struck down quickly. Like a fixed Welding Curtain, a screen's fabric needs to meet AS 1441.13 fire-retardant requirements, and using it to physically screen the work area satisfies the same duty under AS 1674.1 — Welding Safety (Hot Work / Fire Precautions).
Read AIMS's full Welding Blankets & Curtains Guide (AS 1674.1 Hot Work) →
What Is a Wheel Bearing?
A wheel bearing is the bearing assembly inside a vehicle's wheel hub that lets the wheel spin freely on its axle or spindle while still carrying the vehicle's weight and cornering loads — on most Australian trucks and trailers, this is a tapered roller bearing pair (an inner and outer race set), the same bearing type covered in AIMS's own Tapered Roller Bearing entry, packed with grease and sealed with a dust cap. AIMS stocks Koyo/JTEKT trailer bearing kits (packaged with matched inner/outer bearings, seal, split pin and dust cap for common trailer hub fitments), alongside its broader tapered roller bearing range for anyone building up a hub assembly from individual components rather than a packaged kit.
What Is a Wheel Chock?
A wheel chock is a wedge placed hard against a stationary vehicle's tyre to stop it rolling — mandatory practice under WHS Regulation 213 (Powered Mobile Plant) wherever a heavy vehicle is being loaded, unloaded or worked on with its park brake alone considered insufficient. AIMS's own sizing guidance follows the 25% rule for ground vehicles (chock height should be roughly a quarter of the tyre's diameter), which is why a chock sized for a ute is nowhere near big enough for a semi-trailer or mining haul truck.
Read AIMS's full Wheel Chocks Guide → for sizing by tyre diameter and use across heavy vehicle, mining and aviation applications
What Is Wheel Grade / Hardness (Spec Code)?
Wheel grade (or hardness) is the part of a Grinding Wheel Spec Code that describes how tightly the bond holds the abrasive grain — not the hardness of the abrasive mineral itself. A "soft" grade releases worn grain quickly to keep exposing fresh cutting edges, suited to hard materials that would otherwise glaze a wheel; a "hard" grade holds grain longer, suited to soft materials that would wear a soft wheel away too fast. Matching grade to the material being worked is as important as matching abrasive type.
What Is White-Labelling?
White-labelling is the practice of one company manufacturing or supplying a product that another company then sells under its own brand name and packaging, with no indication of who actually made it.
It's a common arrangement across industrial and trade supply — a specialist manufacturer produces a product to spec, and a distributor or retailer rebrands it as part of its own range, giving the seller a branded product line without building manufacturing capability from scratch. White-labelling is closely related to private-labelling (the retail-focused version of the same idea) and is often the practical path a business takes when testing a new product concept as an MVP before committing to a fully custom, branded product development.
What Is WHS? (Work Health and Safety)
WHS stands for Work Health and Safety — the national legal and regulatory framework governing workplace safety in Australia, built around the model WHS Act developed by Safe Work Australia and duties owed by a PCBU to workers and others.
Most states and territories have adopted the model WHS laws in harmonised form, including Western Australia, which moved from its own Occupational Safety and Health Act to a WHS Act in 2022 — Victoria is the one holdout, still operating under its own Occupational Health and Safety Act 2004. That's the main reason "OHS" still turns up in Victorian paperwork and older trade conversation even though "WHS" is now the standard term everywhere else; the two labels describe essentially the same underlying safety obligations, just under different legislation.
Read AIMS's full WHS Laws in Australia Guide →
What Is a Wicking Grade Threadlocker?
A wicking-grade threadlocker is a low-viscosity Anaerobic Adhesive designed to be applied *after* a fastener is already assembled, drawing itself into the thread engagement by capillary action rather than being applied to the threads before assembly.
It's defined by this application method, not by strength — green (Loctite 290) is the common wicking-grade colour, and it's the practical fix for fasteners that are discovered to have worked loose after the fact, where disassembling the joint just to apply a standard threadlocker isn't realistic.
Read AIMS's full Loctite Threadlocker Guide →
Shop AIMS's range of threadlockers →
What Is a Winding (Motor Winding)?
A motor winding is a coil of insulated copper wire, wound a specific number of turns around a core — the wire gauge, turn count and connection pattern of a winding are what actually set a given motor's voltage, speed and torque characteristics for its Motor Frame Size. In an induction motor, the primary winding sits in the Stator — wire coils inserted into slots within the steel laminations that make up the stator core — while the "secondary winding" isn't really a wound coil at all, but the cast rotor assembly, which forms a closed conductive loop rather than the same discrete coil-and-slot construction as the stator side. This is exactly what makes the rotor able to be driven purely by electromagnetic induction, with no physical electrical connection to the stator — see Rotor and Stator and Induction Motor.
(Windings are mentioned throughout AIMS's own motor and insulation-class content above rather than covered as a standalone topic in one dedicated guide — this entry is written to general, well-established motor-winding engineering fundamentals rather than to a single AIMS citation.)
What Is a Wing Nut?
A wing nut is a nut with two flat radial "wings" instead of a hex or round outer profile, allowing it to be tightened and loosened entirely by hand — no spanner or socket required — at the cost of significantly lower achievable clamp force and torque than a tool-driven nut.
DIN 315 is the metric standard for wing nuts (rounded wing profile); DIN 315 A is the American variant with squared, flat-topped wings for a more aggressive hand grip. AIMS's own guide notes three manufacturing tiers with real durability differences — stamped (lowest strength, wears quickly), cold-formed (AIMS's standard stock, genuinely industrial-grade), and hot-forged (highest strength, for repeated heavy-duty engineering use) — and flags wing nuts as unsuitable for vibration environments or rotating machinery, where the protruding wings become a snagging hazard.
Read AIMS's full Wing Nut Guide → for DIN 315 sizing, manufacturing types and material options
Shop AIMS's range of wing nuts →
What Is Wire Brush Fill Material — Steel, Stainless or Brass?
Wire brush fill material is chosen to suit both the job and the workpiece. Carbon steel fill gives the most aggressive general-purpose cleaning and rust removal but will embed ferrous particles that can rust on a stainless surface. Stainless steel fill avoids that cross-contamination risk, making it the correct choice whenever the workpiece itself is stainless. Brass fill is the softest of the three, used where the job calls for cleaning without scratching a softer base metal or leaving any ferrous residue behind — electrical contacts and softer non-ferrous metals, for instance. See Knotted Wire Brush and Crimped Wire Brush above for the other half of the selection.
What Is Wire Rope?
Wire rope is a rigging and lifting cable made from multiple steel wires twisted into strands, which are then twisted together around a core. Australian wire rope is most commonly supplied in metric diameters (6mm, 8mm, 10mm, 12mm and up), though imperial sizing (1/4", 3/8", 1/2") still turns up on older equipment and imported gear.
See Wire Rope Construction for how the strands × wires-per-strand notation trades off flexibility against abrasion resistance, Wire Rope Lay for the twist direction and pattern, IWRC for the steel-core option that adds crush resistance, and Thimble and Wire Rope Grip for how a rope end is finished and terminated in the field.
Read AIMS's full Wire Rope Guide → (construction and termination) or Wire Rope Sling & Rigging Guide → (WLL, angles and discard criteria)
Shop AIMS's range of wire rope, chain & fittings →
What Is Wire Rope Construction (1×19, 7×7, 7×19, 6×19, 6×36)?
Wire rope construction notation describes the number of strands and the number of wires per strand — 1×19 is a single strand of 19 wires, stiff and low-stretch, suited to architectural and structural cable rather than dynamic lifting; 7×7 (seven strands of 7 wires) balances flexibility and general-purpose use; 7×19 (seven strands of 19 wires) is the most flexible common construction and the standard for slings and other dynamic lifting applications; 6×19 and 6×36 IWRC (six strands of 19 or 36 wires around a steel core) are the heavy-lifting and high-cycle hoist constructions. The general trade-off holds across all of them: more, thinner wires make a more flexible rope, while fewer, thicker wires make a more abrasion-resistant one — see IWRC above for what the steel-core option adds.
What Is a Wire Rope Grip (U-Bolt Clip)?
A wire rope grip (U-bolt clip) is a fitting used to terminate a wire rope in a field application by clamping it back onto itself, governed in Australia by AS 2076. The standard rule is a minimum of three grips spaced six rope diameters apart, with the grip's saddle always on the load-bearing (live) side of the rope and the U-bolt on the tail (dead) side — "never saddle a dead horse," as the trade saying goes — which, correctly torqued, retains roughly 80–90% of the rope's minimum breaking load. AS 2076 covers non-lifting applications specifically; a genuinely load-rated lifting termination should use a swaged fitting or a Thimble-and-clip combination confirmed against the rope manufacturer's rating, not a field clip alone.
Shop AIMS's range of wire rope, chain & fittings →
What Is Wire Rope Lay?
Wire rope lay describes the direction and pattern in which the wires and strands are twisted during manufacture — most general industrial wire rope is right-hand regular lay, where the wires within each strand twist in the opposite direction to the strands themselves, giving a rope that resists kinking and is straightforward to handle in the field. Lay matters when replacing rope on an existing drum or block: matching the original lay keeps the rope's handling characteristics and wear pattern consistent with what the equipment was set up for.
What Is the WLL Colour Code for Synthetic Slings?
The WLL colour code is a visual system, set out in AS 1353 (webbing) and AS 4497 (round slings), that lets a rigger identify a synthetic sling's Working Load Limit at a glance by its colour: violet is 1 tonne, green 2 tonnes (the most common in general AU workshop use), yellow 3 tonnes, grey 4 tonnes, red 5 tonnes, brown 6 tonnes, blue 8 tonnes, and orange 10 tonnes and above. It's a quick first check, not a replacement for reading the actual WLL tag — the colour tells you the rating at a glance, but the tag is still the legal record and should always be confirmed before a lift.
Read AIMS's full Webbing & Round Slings Guide → for the complete colour-code and WLL reference
What Is a Workbench?
A workbench is a sturdy, purpose-built bench — fixed or mobile — for holding work while filing, clamping, assembling or fitting, typically fitted with a Bench Vice and built heavy enough to resist the vibration and leverage of hand-tool work without moving underneath it.
A genuinely useful workbench is rated for the loads and vibration the work will actually put on it — a light general-purpose bench flexes and walks under the leverage of vice work or hammering, where a heavier, purpose-built steel-framed bench stays planted.
Shop AIMS's range of workbenches →
What Is Working Load Limit (WLL)?
Working Load Limit (WLL) is the maximum load a piece of lifting or rigging equipment is rated to carry safely under normal conditions, stamped on the item in kilograms or tonnes. It is not a theoretical breaking point with no safety margin built in — WLL already accounts for the equipment's safety factor, so it should never itself be exceeded, "just this once" or otherwise.
WLL is one of four related terms that get mixed up in the trade, and knowing the difference actually matters on site. SWL (Safe Working Load) is the older, now-retired term — it was officially replaced because of the legal weight the word "safe" carried, but it's still stamped on older equipment and can generally be read as equivalent to WLL if the item is currently in-date on inspection. WLL, governed by AS 4991 for below-hook rigging accessories (slings, shackles, hooks, eye bolts, chain), is the current standard term for loose lifting gear. MRC (Maximum Rated Capacity), governed by AS 1418.1 & AS 1418.2 instead, is the equivalent term for the lifting *machine* itself — cranes, hoists, winches, chain blocks — as distinct from the accessories hanging off it. And MBL (Minimum Breaking Load) is the load at which the equipment actually fails under test — never a working figure, but the number WLL is calculated from: WLL = MBL ÷ design factor, where the design factor itself varies by equipment type (wire rope slings 5:1, chain slings 4:1, synthetic slings 5:1–7:1, shackles 4:1–6:1 depending on grade).
The practical point: a complete lifting system is only as strong as its weakest rated component, and that's usually the accessory, not the machine — a 5-tonne MRC hoist paired with a 2-tonne WLL shackle is a 2-tonne system, full stop. WLL applies to Shackles, Chain Slings, Wire Rope, webbing slings and Eye Bolts alike, but the *rated* WLL of a sling or shackle changes with how it's rigged — see Sling Angle Deration and Hitch Types for two of the most common ways a load ends up heavier, effectively, than the numbers on the tag suggest.
Read AIMS's full SWL, WLL, MBL & MRC guide → for the complete design-factor table by equipment type
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## Electrical
What Is a Wrapped V-Belt? (Fabric-Covered)
A wrapped V-belt has a fabric cover bonded over its rubber body, protecting the core from oil, heat and general environmental wear — the traditional, general-purpose V-belt construction most industrial drives have used for decades.
Against a Raw-Edge / Cogged V-Belt, a wrapped belt trades some flexibility and heat dissipation for that extra layer of environmental protection, which is why it remains the default choice for general-purpose drives that aren't running on particularly small-diameter sheaves or in especially hot conditions.
Read AIMS's full V-Belt Sizing & Identification Guide →
Shop AIMS's range of industrial drive & conveyor belts →
Y
What Is Yield Strength?
Yield strength is the stress at which a material stops deforming elastically (springing back to its original shape when the load is removed) and starts deforming permanently. It's usually the number that governs safe working load in practice, since a bolt or component that has permanently stretched has failed, even if it hasn't snapped.
On a metric bolt grade marking, yield strength is calculated as both numbers multiplied together, then by 10 — so a grade 8.8 bolt (8 × 8 × 10) has a yield strength of about 640 MPa, against a tensile strength of 800 MPa. That gap between yield and tensile strength is the working safety margin most fastener designs rely on.
Read AIMS's full Bolt Grade Chart →
Z
What Is Zinc Plating (Clear / Yellow / Phosphate)?
Zinc plating is standard zinc Electroplating finished with one of several conversion coatings that change its colour and corrosion performance: clear (a thin passivate, silvery appearance, the base level of protection), yellow — see Dichromate — (a chromate seal giving a gold tint and "slightly better" resistance per AIMS's own guide), and black or olive phosphate variants used more for appearance and light corrosion protection than heavy-duty outdoor service. All are sacrificial coatings (see Anode / Cathode), meaning the zinc corrodes preferentially to protect the steel underneath even where the coating is scratched — but all are also thin enough (5–25 microns) that they suit indoor or short-outdoor-exposure use rather than the multi-decade outdoor life of Hot Dip Galvanizing.
Read AIMS's full Zinc Plated vs Galvanised vs Stainless: Bolt Coatings Guide →
Shop AIMS's range of zinc-plated fasteners →
What Is Zincalume?
Zincalume is BlueScope's registered trademark for aluminium/zinc/magnesium alloy-coated steel — the same metallic coating that sits under a Colorbond® paint finish, sold here in its bare, unpainted state.
Developed in 1976, Zincalume's alloy coating gives markedly better corrosion resistance and a longer service life than standard zinc-only hot-dip galvanised steel in most environments, which is why it's the default substrate for roofing, wall cladding, garage doors, gutters, fascia and downpipes wherever the natural silver-grey finish is acceptable and colour isn't required. It's manufactured to the AS/NZS 1365 and AS 1397 standards. Colorbond® and Zincalume are frequently compared for uncoloured, budget-sensitive jobs — the short answer is that Zincalume is cheaper and just as corrosion-resistant, while Colorbond® adds colour and a small amount of extra UV/weathering protection from the paint layer itself; see Colorbond® for that side of the comparison.
