Product Guides
Clevis Pin Guide: Types, Sizes, Materials, and Retention Methods
A clevis pin is an unthreaded cylindrical fastener that passes through a clevis bracket and a mating component to form a pivoting joint. Unlike a bolt, a clevis pin is retained at the open end by a split pin, R-clip or nut rather than by threading — making the joint quick to assemble, disassemble and adjust while allowing free rotation between the connected parts. Clevis pins are found throughout Australian industry: tractor three-point linkages, hydraulic ram ends, conveyor pivot arms, wire rope turnbuckle jaws, rigging assemblies, trailer couplings and agricultural implement connections all rely on them. This guide covers types, DIN 1444 metric sizes, materials, retention methods and how to identify a replacement when you no longer have the original specification. Clevis Pin Sizes — Metric Reference Table (DIN 1444) — Quick Reference The table below covers the most common DIN 1444 Form B metric clevis pin sizes stocked in the Australian market. Lengths shown are standard stock lengths; non-standard lengths are available to order for volume requirements. Nominal Diameter Common Stock Lengths Cross-Hole Dia. Typical Application 5mm 20, 25, 30mm 1.6mm Light linkages, small instrument pivots, light sheet metal brackets 6mm 20, 25, 30, 40mm 2.0mm Small hydraulic linkages, light conveyor pivots, bicycle and light vehicle linkages 8mm 25, 30, 40, 50mm 2.5mm Medium equipment pivots, small brake and throttle linkages, light implement connections 10mm 30, 40, 50, 60mm 3.2mm Agricultural 3-point linkage (light implements), medium machinery pivots, gate hardware 12mm 40, 50, 60, 80mm 4.0mm Heavy agricultural connections, trailer pivot points, medium hydraulic cylinder pins 16mm 50, 60, 80, 100mm 5.0mm Drawbar connections, heavy plant pivots, large trailer coupling connections 20mm 60, 80, 100, 120mm 6.3mm Heavy construction plant, large hydraulic rams (boom and arm pins), marine rigging assemblies 25mm 80, 100, 120, 150mm 8.0mm Very heavy plant, large rigging assemblies, mining equipment pivots 30mm 100, 120, 150mm 8.0mm Heavy-duty lifting gear, large mining and earthmoving equipment pivot connections What Is a Clevis Pin? The name comes from the clevis — a U-shaped or forked bracket with aligned holes through both ears. The clevis pin slides through one ear, then through the mating part (a rod eye, chain link, shackle or bracket), then out through the other ear. A retaining device through the cross-hole at the exposed end prevents the pin from backing out. Clevis pin retention via cotter pin is one method — for the castellated-nut-plus-cotter-pin alternative used on rotating shafts and wheel hubs, see the AIMS castle nut guide. Because the pin is unthreaded and free to rotate within the hole, it creates a true pivot joint: the connected components can rotate relative to one another around the pin axis without generating thread fatigue or loosening torque. This is why clevis pins are preferred over bolts wherever cyclical rotation, oscillation or angular movement occurs under load. The three-part assembly — clevis bracket, clevis pin, retaining device — is one of the oldest and most reliable mechanical joints in engineering. In the Australian agricultural and industrial context, you will see it referred to variously as a hitch pin, drawbar pin, linch pin (though that is technically a different fastener) or simply a clevis. Whatever the local name, the geometry and function are identical. A clevis pin is a shear-loaded fastener. In double-shear (the standard clevis arrangement where both ears of the bracket are engaged), the pin carries the applied load across two shear planes simultaneously. This is more efficient than a bolt in the same arrangement, and is why clevis pins of modest diameter can handle surprisingly high loads when the material and geometry are correctly matched to the application. Types of Clevis Pins Standard Clevis Pin (DIN 1444 Form B) The most common type. Has a domed or flat head at one end and a cross-hole drilled through the shank near the other end for a split pin or R-clip. Available in metric diameters M5 through M30 and a range of grip lengths. This is the pin you will find in most general industrial, agricultural and lifting applications in Australia. The Form B designation confirms the cross-hole is present — Form A (no cross-hole) is less common and used only where an alternative retention method is designed into the assembly. Headless / Shoulder Clevis Pin Used where the pin must pass through from one side only, or where head clearance above the clevis ear is restricted. Common in hydraulic cylinder rod-end and base-end connections and precision pivot assemblies on production machinery. The shoulder (a step-down diameter) provides the retention face at one end; the cross-hole or snap-ring groove retains the other end. On hydraulic cylinders, the shoulder pin is often retained by a snap ring (circlip) seated in a groove machined into the clevis ear rather than by an external split pin. Multi-Hole Clevis Pin Has multiple cross-holes drilled along the shank at regular intervals, allowing the effective grip length to be adjusted without removing the pin from the clevis assembly. Used extensively in three-point linkage systems, cultivator frames, toolbar connections and implement height adjusters, where the operator needs to set depth or position increments in the field without a toolkit. The Champion CPMH01 range stocked by AIMS is a typical example: two or more holes let the operator select the engagement point by repositioning the R-clip. Threaded-End Clevis Pin Has a standard domed head at one end and a threaded shank at the other, retained by a nyloc nut and washer. Used in applications where positive, non-backing-out retention is required and tool access at the retention end is available. Less common in field-service applications than the split-pin type but preferred in fixed machinery where vibration is high and the joint is not designed for frequent adjustment. The nut should be tightened to a snug fit — not hard torqued — to preserve free rotation of the pin in the clevis. DIN 1444 — The Standard That Applies in Australia Australian industry uses metric clevis pins manufactured to DIN 1444 (German standard, widely adopted internationally), which defines two forms: Form A — head only, no cross-hole. Used where the pin is retained by another method (circlip groove, grub screw, press fit) or where the assembly is not intended for field disassembly. Form B — head plus cross-hole drilled through the shank near the retention end. The standard workshop and field-service pin. This is what AIMS stocks and what you will find in most hardware and industrial supply catalogues in Australia. The DIN 1444 standard specifies nominal diameter, tolerance class (typically h11 — a slightly loose fit to allow rotation), cross-hole diameter and position, and head dimensions. The h11 tolerance means a 10mm DIN 1444 clevis pin will have an actual diameter of 9.94–10.00mm. The mating clevis holes are typically drilled to 10.5mm (normal fit) for easy assembly and to allow the joint to rotate freely without binding. The standard also specifies the cross-hole diameter relative to pin diameter, so split pins and R-clips sized to the pin will fit correctly without play. A 10mm DIN 1444 pin has a 3.2mm cross-hole; a 12mm pin has a 4.0mm cross-hole; a 16mm pin has a 5.0mm cross-hole. This relationship is what allows you to select the correct split pin simply by knowing the clevis pin diameter. Imperial clevis pins made to ANSI/ASME standards are still in use in Australia, primarily on older US-manufactured agricultural equipment, some British-origin machinery and North American-sourced trailers and attachments. These use inch-fraction diameters and their cross-holes are sized to inch-fraction split pins and R-clips. Where you have a mix of metric clevis hardware and imperial-specification pins on the same machine, do not interchange them without checking the hole sizes match — the dimensional tolerance system differs between DIN and ANSI. Clevis Pin Sizes — Metric Reference Table (DIN 1444) The table below covers the most common DIN 1444 Form B metric clevis pin sizes stocked in the Australian market. Lengths shown are standard stock lengths; non-standard lengths are available to order for volume requirements. Nominal Diameter Common Stock Lengths Cross-Hole Dia. Typical Application 5mm 20, 25, 30mm 1.6mm Light linkages, small instrument pivots, light sheet metal brackets 6mm 20, 25, 30, 40mm 2.0mm Small hydraulic linkages, light conveyor pivots, bicycle and light vehicle linkages 8mm 25, 30, 40, 50mm 2.5mm Medium equipment pivots, small brake and throttle linkages, light implement connections 10mm 30, 40, 50, 60mm 3.2mm Agricultural 3-point linkage (light implements), medium machinery pivots, gate hardware 12mm 40, 50, 60, 80mm 4.0mm Heavy agricultural connections, trailer pivot points, medium hydraulic cylinder pins 16mm 50, 60, 80, 100mm 5.0mm Drawbar connections, heavy plant pivots, large trailer coupling connections 20mm 60, 80, 100, 120mm 6.3mm Heavy construction plant, large hydraulic rams (boom and arm pins), marine rigging assemblies 25mm 80, 100, 120, 150mm 8.0mm Very heavy plant, large rigging assemblies, mining equipment pivots 30mm 100, 120, 150mm 8.0mm Heavy-duty lifting gear, large mining and earthmoving equipment pivot connections A note on grip length: The grip length is the usable shank length between the underside of the head and the centre of the cross-hole. When ordering, confirm that the grip length matches the combined thickness of the clevis ears and the mating part. The cross-hole should clear the outer clevis ear face by at least 3–5mm to allow the split pin legs to be spread or the R-clip to seat fully. Tolerance and fit: DIN 1444 Form B pins are manufactured to h11 tolerance. The mating hole in the clevis bracket should be drilled to H12 tolerance for a normal running fit, or H11 for a close fit. For standard off-the-shelf clevis hardware (turnbuckles, connecting links, hydraulic cylinder rod ends), the clearance fit is designed into the product — simply match the pin diameter to the specified pin size for that fitting. Imperial Clevis Pin Sizes For workshops maintaining older US-origin or British-origin equipment, the following imperial sizes are the most commonly encountered in Australia. Imperial sizes are typically specified in fractional inches for the diameter and whole or fractional inches for the length. Imperial Diameter Metric Equivalent Common Lengths Typical Application 3/16" 4.76mm 3/4", 1", 1-1/4" Light implement connections, cable clevis fittings 1/4" 6.35mm 3/4", 1", 1-1/2" Small drawbar links, trailer safety chain connections 5/16" 7.94mm 1", 1-1/2", 2" Medium agricultural attachments, light lifting hardware 3/8" 9.53mm 1", 1-1/2", 2", 2-1/2" Standard implement hitch pins on older US equipment 1/2" 12.7mm 1-1/2", 2", 2-1/2", 3" Drawbar clevis connections, heavy implements 5/8" 15.88mm 2", 2-1/2", 3", 4" Heavy drawbar, tractor three-point top link (US-spec) 3/4" 19.05mm 2-1/2", 3", 4", 5" Heavy plant, large trailer couplings, US-spec drawbars The Metric/Imperial Crossover Problem in Australian Agriculture This is a real practical issue. Many tractors and implements sold in Australia from the mid-2000s onwards — particularly Chinese-manufactured machines sold under Australian brand names — use clevis geometry that sits between the metric and imperial systems. A nominally 10mm metric clevis hole may accept a 3/8" (9.53mm) imperial pin with slightly looser clearance, and vice versa. This occurs because the Chinese manufacturing supply chain has historically mixed metric and imperial tooling, and the dimensional differences at these sizes are small enough that the pin physically fits even though it is not the correct specification. The practical guidance: if you are replacing a worn pin on Asian-origin equipment and cannot find the original specification, measure the clevis hole diameter in millimetres. If the measurement is exactly a metric value (10.0mm, 12.0mm, 16.0mm), specify a DIN 1444 metric pin. If the measurement corresponds to an imperial fraction (9.5mm ≈ 3/8", 12.7mm = 1/2"), specify an imperial pin. If in doubt, specify the metric size that is closest to the measurement and check the fit before committing to a batch. A metric DIN 1444 pin is usually the safer choice in Australia as it is more widely stocked and its tolerance system is better documented. Clevis Pin Materials Mild Steel, Zinc-Plated (Grade 4.6 Equivalent) The standard material for general industrial and agricultural use. Zinc electroplating (typically 5–8 microns) provides moderate corrosion resistance suitable for sheltered environments, workshop use and most field conditions where the pin will be periodically replaced as a wear item. The steel substrate is mild steel with a minimum tensile strength of around 400 MPa, adequate for the shear loads in standard DIN 1444 applications. Hot-dip galvanised clevis pins are also available for outdoor agricultural applications where corrosion resistance must outlast a regular maintenance cycle. The thicker zinc layer (85 microns minimum to AS/NZS 4680) provides significantly better protection at the cost of slightly reduced dimensional precision. Zinc-plated mild steel is not suitable for permanently wet, coastal, food-processing or chemical environments. In those applications, specify stainless steel. Grade 316 Stainless Steel The correct choice for marine, coastal, food-processing and chemical-processing environments. Grade 316 contains 2–3% molybdenum, which provides significantly better pitting and crevice corrosion resistance than Grade 304 in the presence of chlorides — including seawater, salt-laden coastal air and chlorinated cleaning solutions. If a clevis pin is used in rigging on a boat, near a harbour, in carwash equipment, in seafood processing, in coastal outdoor applications or in any chemical plant with halide exposure, Grade 316 is the minimum acceptable specification. Tensile strength of 316 stainless is typically 515–690 MPa depending on temper and form — comparable to Grade 4.6 mild steel for most clevis pin applications. The significant benefit is corrosion resistance, not strength. Do not substitute Grade 304 for Grade 316 in saltwater or chloride environments. Crevice corrosion and pitting failure in Grade 304 clevis pins used in marine rigging is a documented failure mode that can lead to pin seizure, fracture or the inability to disassemble the joint. Grade 304 Stainless Steel Suitable for general corrosion resistance in non-marine, non-chloride environments. Commonly used in food-preparation areas where cleaning agents are mild (no chlorine-based sanitisers), in refrigeration equipment, in light outdoor applications not subject to salt exposure, and in chemical environments where chlorides are absent. Grade 304 is significantly cheaper than Grade 316 and is adequate for many industrial applications, but its chloride corrosion resistance limit must be respected. High-Tensile Steel (Grade 8.8 Equivalent and Above) Used where a clevis pin is load-rated and the shear strength of a standard DIN 1444 Grade 4.6 equivalent pin is insufficient for the application. Lifting shackle pins, clevis shortening hooks, crane rigging hardware and rated agricultural drawbar connections use high-tensile or alloy steel pins with defined Working Load Limits (WLL). These are not general-purpose DIN 1444 pins — they will have a WLL, grade marking and/or traceability number stamped on them. They must be used within their rated limits and must not be substituted with standard commercial clevis pins. AIMS stocks rated clevis lifting hardware (Grade 80 and Grade 100 clevis hooks and master links) as separate products from the standard DIN 1444 pin range. If you are selecting a pin for a safety-critical or load-rated lifting application, contact AIMS to confirm the correct rated product. Retention Methods Split Pin (Cotter Pin) The most common retention method for DIN 1444 Form B clevis pins. A split pin — also called a cotter pin in American usage — is inserted through the cross-hole and the two legs are spread outward (typically at 90° to each other, with one leg bent back) to resist withdrawal. The split pin provides positive, visible retention: if the split pin is missing, the joint is immediately identifiable as unretained. Split pins are one-use items — once bent, they must be replaced on reassembly. Attempting to re-use a bent split pin risks fatigue fracture of the leg during or after installation. Always carry spare split pins of the correct diameter when working on agricultural or industrial equipment in the field. See the Split Pin & Cotter Pin Guide for full sizing, types and installation guidance. Size the split pin to the cross-hole diameter in the DIN 1444 specification for the pin diameter. R-Clip (Hairpin Cotter / Lynch Pin) A spring-steel wire formed into an R or hairpin profile that clips through the cross-hole and springs outward to resist withdrawal. Tool-free installation and removal — the key advantage over split pins in applications where the joint is frequently adjusted: agricultural implement depth settings, drawbar length adjusters and toolbar connection points. R-clips are reusable through many cycles. R-clips must be inspected regularly and replaced when fatigued. A correctly tensioned new R-clip provides substantial retention force from the spring action; a worn, flattened or permanently deformed R-clip may fall out of the cross-hole under vibration. R-clips are the correct choice for frequently adjusted connections, but are not the right choice where positive, tamper-evident retention is required and the joint is rarely disassembled. Wire Lock Pin (Safety Pin) A solid pin body with an integrated spring-wire lock. The wire passes through the cross-hole and locks automatically. Provides secure, vibration-resistant retention while remaining tool-free for removal. Used on lifting equipment, safety-critical pivot connections and applications where an R-clip may vibrate loose under sustained cyclic loading. The wire lock must be fully seated in the cross-hole to be effective — inspect before use. Nut and Washer (Threaded-End Pins) For threaded-end clevis pins, a standard or nyloc nut with a flat washer provides the retention. The nut should be tightened to a snug fit that eliminates axial float — not torqued hard, as over-tightening binds the joint and generates lateral side loads on the pin. Use a nyloc nut wherever vibration is present to prevent self-loosening. In high-vibration applications, a castle nut with a split pin through a drilled shank may be the most reliable option. Roll pins serve a different retention function — they lock a component to a shaft by interference fit rather than retaining a pin against withdrawal. For gear, sprocket, and lever retention on rotating shafts using a spring steel roll pin, see the Roll Pin (Spring Pin) Guide. Agricultural and Heavy Equipment Applications Clevis pins are among the most frequently replaced consumable fasteners in Australian agricultural and construction equipment. The high-cycle loading of three-point linkage connections, hydraulic top link attachments and drawbar links causes progressive wear in both the pin and the clevis ears, typically appearing as a loose, rattling joint before connection failure. Three-Point Linkage (3PL) Pins Australian tractor manufacturers generally follow the ASAE/ISO Category system for three-point linkage pin dimensions. These are commonly referred to as Cat 1, Cat 2 or Cat 3 pins in Australian rural supplies: Category 1: Lower link pin 22.4mm diameter, top link pin 19.3mm diameter. Suits compact and mid-range tractors. Category 2: Lower link pin 28.7mm diameter, top link pin 25.5mm diameter. Suits medium to large farm tractors. Category 3: Lower link pin 37.4mm diameter, top link pin 31.8mm diameter. Suits large four-wheel drive tractors and high-horsepower implements. Standard Australian rural supply outlets stock pins to these specifications in mild steel (zinc or galvanised), Grade 316 stainless, and hardened steel for high-wear applications. Category pins are retained by R-clips or lynch pins in almost all field applications for ease of implement changeover. Hydraulic Cylinder Connections Hydraulic cylinder rod-end and base-end clevis connections use shoulder or headless pins in most designs. The pin diameter is specified in the cylinder's engineering data and must be matched exactly — an undersized pin will wear rapidly under the side-loading from cylinder force vectors. On excavators, loaders and agricultural hydraulic systems, these pins are designed as replaceable wear items with defined service intervals. Hardened or case-hardened pins are preferred in high-cycle applications to extend service life. Drawbar and Towing Connections Drawbar clevis connections on trailers and agricultural equipment use larger-diameter pins (typically 16–32mm) and must be selected to carry the drawbar tongue weight and dynamic tow loads. In transport applications subject to Australian Road Rules requirements, the pin and clevis assembly must meet the coupling rating (typically expressed as a D-value or tow rating in the vehicle or equipment certification). Do not substitute a lighter pin for a rated tow coupling pin. Marine and Rigging Applications Clevis pins in marine rigging are a specialised application with requirements distinct from general industrial use. Wire rope terminations (swaged fittings, Sta-Lok, Norseman), turnbuckle jaw ends and chainplates all rely on clevis pins that must meet a different standard: Material without exception: Grade 316 stainless steel in all saltwater environments. Grade 304 is not acceptable. Retention: In standing rigging, clevis pins are typically retained with a stainless split ring (cotter ring) rather than a split pin, to prevent sharp bent-leg ends from snagging sails, lines or crew. Some class rules and manufacturers specify a specific retention method — check the rig specification before changing pin or retention type. Dimensional match: Marine clevis fittings are designed to a specific pin diameter and the WLL is rated for that exact diameter. Do not mix pin diameters across a fitting family. Inspection interval: Standing rigging clevis pins should be inspected at each annual rig inspection and whenever the rig is unstepped. Look for pitting, crevice corrosion at the pin-to-fitting interface, surface blistering and any visible bending of the pin shank. Clevis pins in load-rated rigging hardware — bow shackles, dee shackles, clevis shortening hooks, master links — are purpose-designed components with defined WLLs and are not interchangeable with standard DIN 1444 pins. See the Bow Shackle Guide for load-rated rigging hardware. For turnbuckles with jaw (clevis) ends, see the Turnbuckle Guide. Clevis Pin Inspection and Maintenance Clevis pins are wear items. In high-cycle or abrasive applications, periodic inspection and timely replacement prevents joint failure and the associated downtime and safety risk. What to Inspect Pin diameter wear: Measure the pin at the primary shear plane (midpoint between the clevis ears, where loading is concentrated). More than 5% reduction from nominal diameter is cause for replacement. For a 12mm pin, that is 11.4mm — visible with a vernier caliper. Flats and grooving: A pin that has been prevented from rotating (by a too-tight fit or a seized cross-hole) will develop wear flats on one side. A grooved or flatted pin should be replaced even if the diameter reduction is less than 5%, as the remaining section at the wear flat may be below the load-bearing minimum. Cross-hole condition: Check that the cross-hole is clear, the edges are not mushroomed, and a new split pin or R-clip will seat correctly. A mushroomed cross-hole mouth prevents proper split pin installation and is a sign of previous incorrect assembly (oversized split pin forced through). Clevis ear condition: Inspect the clevis bracket holes as well as the pin. An oval hole (worn from round) accelerates further pin wear and may allow the pin to shift laterally under load. A mildly oval hole can sometimes be reamed to the next standard size up with a matching larger pin; a severely worn or cracked clevis ear requires bracket replacement. Corrosion: Surface rust on zinc-plated pins is cosmetic; pitting that has reduced the shank cross-section is cause for replacement. In stainless pins, look for crevice corrosion (dark discolouration at the pin-to-fitting interface) and pitting in the shank. Do not abrade or polish away pitting — replace the pin. Lubrication Clevis pins in rotating or oscillating applications benefit from periodic lubrication. A light application of general-purpose grease at assembly reduces friction-induced wear and helps prevent fretting corrosion at the shear plane. In agricultural equipment, a grease nipple in the clevis ear body is common practice on high-wear connections. In marine applications, anti-seize compound (not grease) on stainless pins prevents galling during assembly and reduces crevice corrosion risk at the pin-fitting interface. How to Choose the Right Clevis Pin Follow these steps to select the correct clevis pin for any application: Step 1 — Determine the required diameter Measure the hole diameter in the clevis ears with a vernier caliper. The pin diameter should be a close sliding fit — for a DIN 1444 h11 tolerance pin in a standard H12 clevis hole, there will be approximately 0.1–0.3mm clearance. If the clevis hole has worn oval, ream it to the next standard size up and fit a correspondingly larger pin. Step 2 — Determine the required grip length Measure the combined thickness of both clevis ears and the mating component at the pin centreline. The grip length of the pin (from head underside to cross-hole centre) should equal this combined thickness, plus 3–5mm to allow the split pin or R-clip to be fitted clear of the outer ear face. If the mating component has a boss or bearing surface that floats axially on the pin, account for the full float range when calculating the required grip length. Step 3 — Select the pin form For most agricultural, industrial and maintenance applications: DIN 1444 Form B (drilled cross-hole) with split pin or R-clip. For frequently adjusted connections (implement depth settings, drawbar adjusters): Form B with R-clip. For hydraulic cylinder rod and base-end connections: shoulder/headless type to match the cylinder specification. For adjustable implement toolbar connections: multi-hole type. Step 4 — Select the material General industrial or agricultural in sheltered conditions: mild steel zinc-plated. Exposed outdoor agricultural in wet conditions: hot-dip galvanised. Coastal, marine, food-processing or chemical environments: Grade 316 stainless. Load-rated lifting or structural: rated clevis pin to WLL specification — not a DIN 1444 commercial pin. Step 5 — Select the retention method Infrequent assembly, safety-critical: split pin (positive, one-use, cheap). Frequent field adjustment: R-clip (reusable, tool-free). High-vibration with infrequent adjustment: wire lock pin or castle nut + split pin. Size the split pin or R-clip to the cross-hole diameter in the DIN 1444 specification for the selected pin diameter — these are directly correlated and documented in the standard. How to Identify a Replacement Clevis Pin When the original pin has been lost, worn beyond recognition or the equipment documentation is unavailable, use this procedure: Measure the clevis hole diameter with a vernier caliper — measure at two points 90° apart to check for oval wear. If the hole is oval, the measurement at the minor axis (smallest diameter) is your target pin size. Record in millimetres. Measure the clevis ear thickness on each ear individually, and the thickness of the mating component. Add these three measurements together for the required grip length (plus the 3–5mm cross-hole clearance allowance). Check the cross-hole position on any remaining section of the old pin — the distance from the tip of the shank to the cross-hole centre tells you whether the grip length calculation is correct. Determine metric or imperial — if the clevis hole measures exactly 9.5mm, 12.7mm, 15.9mm or another imperial inch-fraction equivalent, you are dealing with an imperial-specification fitting. Cross-reference with the imperial size table above. Identify the correct material from the operating environment — marine, coastal or food-processing environment specifies Grade 316 stainless. General industrial or agricultural specifies zinc-plated mild steel unless extended corrosion resistance is needed. Check the retention end geometry — confirm whether the original pin had a drilled cross-hole (DIN 1444 Form B), a threaded end, a snap-ring groove or a different retention feature. Do not fit a Form B pin into an assembly designed for a threaded-end pin without understanding why the design specified threaded retention. If you are unsure after measuring, bring the worn pin (or the clevis ear assembly if it can be removed) to the AIMS counter. Our team can cross-reference to the correct stocked size and confirm material specification. Clevis Pins at AIMS Industrial AIMS stocks a comprehensive range of clevis pins for general industrial, agricultural and maintenance applications across Australia: DIN 1444 Form B metric clevis pins in mild steel zinc-plated — M5 through M30, standard length range Grade 316 stainless steel clevis pins — metric sizes M6 through M20 Imperial clevis pins — 3/16" through 3/4" diameter for maintenance of older US and British-origin equipment Champion CPMH01 multi-hole clevis pins for adjustable implement connections Matching R-clips (hairpin cotters / lynch pins), split pins and wire lock pins View the full clevis pin range at AIMS Industrial → For volume orders, agricultural fleet pin kits, non-standard lengths or help identifying a replacement, contact the AIMS team on (02) 9773 0122 or via the contact page — we carry the reference material to match most applications. Frequently Asked Questions What is a clevis pin? A clevis pin is an unthreaded cylindrical fastener that passes through a U-shaped clevis bracket and a mating component to create a pivoting joint. It is retained at one end by a split pin, R-clip or nut. Unlike a bolt, a clevis pin allows free rotation between the connected parts, making it the correct choice for joints that experience cyclic movement, oscillation or angular displacement under load. What is the difference between a clevis pin and a cotter pin? A clevis pin is the main cylindrical fastener that passes through the joint and carries the load. A cotter pin (split pin) is the retaining device inserted through the cross-hole at the end of the clevis pin to prevent it backing out. They work as a pair — the clevis pin carries the shear load; the cotter pin holds it in place. See the Split Pin & Cotter Pin Guide for full cotter pin sizing and selection. What is another name for a clevis pin? Clevis pins are called hitch pins, drawbar pins, pivot pins or implement pins in Australian agricultural usage. The retaining device may be called a split pin, cotter pin, R-clip, lynch pin or hairpin cotter depending on type and region. In marine rigging the clevis pin may simply be called a rigging pin. Is a clevis pin stronger than a bolt? Strength depends on diameter, material and grade — there is no universal answer. A standard DIN 1444 mild steel clevis pin (Grade 4.6 equivalent) is weaker in shear than a Grade 8.8 bolt of the same diameter. However, clevis pins are designed to operate in double shear and perform well in that loading mode. The correct question is whether the selected clevis pin is appropriately rated for the shear load in the joint — size, material and form matter more than a bolt comparison. What size clevis pin do I need for a Category 1 three-point linkage? Category 1 (ISO 730 / ASAE S217) lower link pins are 22.4mm diameter; the top link pin is 19.3mm diameter. For Category 2 (larger tractors), lower link pins are 28.7mm and top link is 25.5mm. Category 3 uses 37.4mm lower link pins. These are sold as 'Cat 1', 'Cat 2' and 'Cat 3' pins in Australian rural supplies and farm machinery outlets. What is the difference between an R-clip and a split pin for a clevis pin? A split pin (cotter pin) is a single-use, positively retained fastener that is bent through the cross-hole — secure, tamper-evident, but requires tools and must be replaced every time the pin is removed. An R-clip (lynch pin) is a reusable spring-steel wire clip that inserts and removes tool-free, ideal for connections adjusted regularly in the field. For safety-critical or infrequently serviced joints, use a split pin. Inspect R-clips regularly for fatigue and replace if flattened or deformed. What does DIN 1444 mean on a clevis pin? DIN 1444 is a German dimensional standard (widely adopted internationally) that specifies the nominal diameter, tolerance class (h11), cross-hole diameter and position, and head dimensions for clevis pins. Form A has no cross-hole; Form B has a drilled cross-hole for a split pin or R-clip. Purchasing to DIN 1444 ensures dimensional interchangeability with DIN 1444-compliant clevis hardware regardless of manufacturer. Can I use a Grade 304 stainless clevis pin in a marine environment? No — Grade 304 stainless is not suitable for direct saltwater or coastal marine use. It lacks the molybdenum content of Grade 316 and is susceptible to pitting and crevice corrosion in chloride environments. Grade 316 stainless is the correct specification for marine, coastal, offshore and food-processing applications where chlorides are present. In fresh water or sheltered inland environments with no chloride exposure, Grade 304 is acceptable. What is a multi-hole clevis pin used for? A multi-hole clevis pin has several cross-holes along the shank at fixed intervals, allowing the effective engagement depth to be adjusted without removing the pin. Widely used on agricultural implement depth wheels, height adjusters and toolbar connection points where the operator needs quick incremental adjustment in the field without a toolkit. The Champion CPMH01 is a commonly stocked example in Australia. How do I measure a clevis pin? Measure the shank diameter with a vernier caliper at the midpoint of the shank (away from head and cross-hole). Measure overall length from head underside to shank tip. For grip length, measure from head underside to the centreline of the cross-hole. When sizing a replacement, always measure the clevis hole diameter (not the worn pin) — worn pins understate the required size. Measure the hole at two points 90° apart to check for oval wear. Where are clevis pins used? Common Australian applications include tractor three-point linkages and drawbars, hydraulic cylinder rod-end and base-end connections, conveyor and production machinery pivot arms, trailer coupling connections, agricultural implement depth and position adjusters, rigging and lifting hardware (rated versions), marine wire rope fittings, turnbuckle jaw ends, and structural tie-rod connections. What is a headless (shoulder) clevis pin used for? A headless clevis pin is used where there is no clearance for a conventional domed head on the entry side of the joint, or where the pin must insert from either direction. Hydraulic cylinder rod-end pins are the most common application — the pin is retained by a snap ring (circlip) in a groove in the clevis ear rather than by a head. Also used in precision machinery pivots where head clearance above the clevis ear is restricted by an adjacent component. How do I choose the grip length of a clevis pin? The grip length is the usable shank from under the head to the centre of the cross-hole. Add the thickness of both clevis ears plus the part between them, then allow 3 to 5mm past the outer ear so the split pin or R-clip seats clear. Too short and the retainer won't fit; too long and the joint has axial slop. See the clevis pins range. Which coating should an outdoor clevis pin have? For sheltered indoor use, zinc-plated mild steel is fine. For exposed outdoor agricultural use, hot-dip galvanised lasts far longer. For coastal, marine or chemical exposure, use grade 316 stainless — zinc coatings and 304 stainless both corrode in salt air. Match the coating to the environment, not just the load. Why is a clevis pin loaded in double shear? In a standard clevis both ears of the bracket support the pin, so the load is carried across two shear planes at once. This double-shear arrangement lets a modest-diameter pin carry a high load, and is why a clevis pin of a given size is effectively stronger in a clevis than the same pin supported at one end only. Match the pin diameter and material to the load. Besides a split pin, how else can a clevis pin be retained? As well as a split pin (cotter pin), a clevis pin can be held by an R-clip (lynch pin) for tool-free, reusable retention on frequently adjusted joints, by a wire lock pin for vibration-resistant tool-free service, or by a threaded end with a nyloc nut where positive non-backing-out retention is needed. Size the retainer to the cross-hole. See cotter pins for the matching split pins. Need to read an engineering drawing? Our GD&T Symbols Guide explains every common geometric tolerance symbol. Pair this with our Metric Bolt Torque Chart for the recommended tightening torque at every M-series bolt.
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Oil Viscosity Chart: ISO VG, SAE & AGMA Conversion Reference
ISO VG grades explained: full 20-grade viscosity chart, SAE to ISO VG conversion tables, AGMA equivalents, and quick grade selectors for hydraulic, gear, compressor and industrial applications.
Read moreIndustrial Degreaser Guide: Solvent vs Aqueous Selection
Pick up the wrong degreaser and you can damage an aluminium component, strip a freshly painted surface, fill a confined workspace with solvent vapour, or simply spend twenty minutes scrubbing something that the right product would have cleaned in thirty seconds. Industrial degreasers look similar on the shelf — spray cans, concentrate bottles, trigger packs — but the chemistry behind them is fundamentally different, and chemistry determines what each one actually does to grease, to surfaces, and to the people using them. This guide covers every type of industrial degreaser used in Australian maintenance and manufacturing environments, explains how they work, and gives you a practical framework for choosing the right one for each job. Whether you are maintaining CNC equipment, servicing conveyor drives, cleaning parts before lubrication or adhesive application, prepping surfaces for welding, or managing workshop floor hygiene, this is the reference you need. AIMS Industrial stocks a range of industrial degreasers, contact cleaners and parts cleaning chemicals for maintenance, engineering and production environments. Contact the AIMS team to discuss your requirements. What Is an Industrial Degreaser? Definition: An industrial degreaser is a chemical cleaning agent formulated to remove hydrocarbon-based contamination — machine oil, cutting fluid, gear lubricant, hydraulic fluid, grease, carbon deposits, bitumen, and wax — from metal, concrete, and other industrial surfaces. Industrial degreasers are distinct from household cleaners in their concentration, the severity of soiling they address, the surfaces and environments they are designed for, and the safety and compliance requirements that govern their use. Degreasers are an essential part of maintenance, repair and operations (MRO) across every sector of Australian industry. They are used as a precursor step before lubricant application, before adhesive bonding, before welding, before painting, before assembly of close-tolerance parts, and as routine housekeeping in any environment where oil and grease contamination accumulates. A surface that has not been properly degreased before a threadlocker, retaining compound, or structural adhesive is applied will fail to cure correctly — the consequences range from fastener back-off to catastrophic joint failure. Industrial degreasers are not interchangeable. The same product that safely strips cutting oil from a steel lathe chuck may etch aluminium alloy components, lift paint from a gearbox housing, or leave a residue incompatible with the adhesive being applied in the next step. Choosing the right degreaser requires understanding the type of contamination, the surface material, the application method, and the workplace safety and environmental requirements. How Degreasing Works: Two Fundamental Mechanisms All industrial degreasers work through one of two basic chemical mechanisms, or a combination of both. Understanding the difference explains why different degreaser types behave differently in practice. Solvent Mechanism Solvent-based degreasers dissolve hydrocarbon contamination by exploiting the principle that like dissolves like. Organic solvents — whether petroleum-derived (mineral spirits, kerosene), chlorinated (trichloroethylene, perchloroethylene), ketone-based (acetone, MEK), or bio-derived (d-limonene from citrus) — share the non-polar molecular structure of oils and greases. They penetrate the contamination, break the molecular bonds holding the grease to the surface, and carry it away as the solvent evaporates or is wiped off. The result is fast, deep cleaning that leaves a dry, residue-free surface — critical for electronics, precision components, and anywhere that moisture would cause problems. The trade-off is that most solvents are flammable, carry VOC exposure risks, and require careful handling and disposal. Surfactant Mechanism (Emulsification) Water-based degreasers use surfactants — detergent molecules with a hydrophobic (water-repelling, oil-attracting) tail and a hydrophilic (water-attracting) head. The surfactant molecules surround oil and grease particles, breaking them into microscopic droplets (micelles) that can be suspended in water. This is emulsification. The emulsified oil droplets are rinsed away with water. Alkaline additives (sodium hydroxide, potassium hydroxide, silicates, phosphates) enhance the surfactant action by saponifying fatty-acid-based oils — converting them to water-soluble soaps. Water-based degreasers are generally safer, less flammable, and easier to handle in large quantities, but they require rinsing, generate contaminated wastewater, and may need heat to work effectively on heavy oil loads. The Main Types of Industrial Degreaser 1. Solvent-Based Degreasers Solvent-based degreasers are the traditional heavy-duty option. They evaporate cleanly, leave no water residue, and cut through the most severe hydrocarbon contamination quickly. They are the correct choice when you cannot afford moisture on the surface, when you need fast evaporation with no rinsing, or when dealing with very heavy petroleum soiling that water-based products struggle to shift in a single application. Petroleum-based solvents (mineral spirits, kerosene, naphtha) are moderate-strength, widely available, and suitable for general engineering and workshop degreasing. They are flammable and have moderate odour. Mineral spirits is the common benchmark — effective on machine oils and greases, safe on most metals including aluminium, and relatively low cost. Chlorinated solvents (historically trichloroethylene, now largely replaced) offered exceptional degreasing power, non-flammability, and fast evaporation — ideal for vapour degreasing tanks. Under current Australian WHS regulations and workplace exposure standards, trichloroethylene (TCE) is subject to strict controls: it is classified as a Category 1A carcinogen, has a Workplace Exposure Standard of 10 ppm TWA, and requires biological monitoring for exposed workers. Many operations that previously used TCE have transitioned to alternative chemistries. If you are still running TCE vapour degreasing tanks, your obligations are significant and ongoing. Non-chlorinated solvent blends — including n-propyl bromide-based, HFC, and engineered solvent blends — are the preferred modern alternative for precision vapour degreasing. They offer high degreasing power without the health and environmental profile of chlorinated solvents, but require careful selection for specific substrate compatibility. Aerosol solvent degreasers (products like CRC Degreaser Heavy Duty, WD-40 Specialist Degreaser) use a propellant to deliver solvent spray. They are practical for spot-cleaning, component access, and areas where a parts washer or immersion tank is not practical. Fast, targeted, residue-free on most metals. Not suited for large surface areas — cost and solvent vapour accumulation become prohibitive. 2. Water-Based Alkaline Degreasers Water-based alkaline degreasers are the workhorse of industrial cleaning. Formulated with surfactants, alkaline builders (sodium hydroxide, potassium hydroxide, silicates, carbonates), and corrosion inhibitors, they handle a broad range of hydrocarbon contamination, are non-flammable, lower in VOC, and suitable for large-volume application — floors, machine exteriors, parts washers. High-alkaline formulations (pH 12+) are effective on heavy, baked-on contamination including carbonised grease, manufacturing soils, and cutting fluid residue. They are not safe on aluminium, copper, zinc, or other amphoteric metals — the caustic chemistry attacks the metal surface. Always check the SDS for surface compatibility. Rinse thoroughly after use on ferrous metals to prevent flash rusting — the alkaline rinse water can accelerate surface oxidation on bare steel. Mildly alkaline formulations (pH 8–11) with corrosion inhibitors are safer for wider material compatibility including aluminium, and are the standard fluid for heated parts washers and recirculating spray cabinets. They are labelled "low-alkaline" or "neutral-to-alkaline" and typically contain inhibitors that form a thin protective layer on metal surfaces during and after cleaning. Concentrated alkaline degreasers are sold as concentrates and diluted before use — typically 1:10 to 1:30 with water depending on soil load. Buying and storing concentrate dramatically reduces cost per litre, waste packaging, and transport volume. For any facility doing regular large-volume degreasing, concentrate is the economical and practical choice. Heat significantly improves the performance of water-based degreasers. A parts washer solution heated to 50–65°C will clean in minutes what cold solution takes thirty minutes to achieve. This is the main reason heated parts washing tanks are standard in production environments — the chemistry works with the thermodynamics. 3. Citrus / Bio-Solvent Degreasers Citrus degreasers use d-limonene — a terpene solvent extracted from citrus peel — as the active cleaning agent. They occupy the space between true solvents and water-based products: they dissolve grease like a solvent, but are biodegradable, derived from renewable sources, less acutely toxic than petroleum solvents, and can be formulated to be water-dispersible (so they rinse away with water). Citrus degreasers are widely used in Australian industry for equipment and machinery cleaning, parts degreasing, chain cleaning, and surface preparation where a plant-derived product is required for environmental or site certification reasons. They are particularly popular in food processing facilities and environmentally sensitive sites. Their key limitation is that they are slower-acting than petroleum or chlorinated solvents on very heavy petroleum contamination, and they leave a slight terpene residue if not rinsed thoroughly — which can interfere with adhesives, coatings, and precision assemblies. Important note on compatibility: citrus solvents are mildly acidic (d-limonene pH ~4–5 in water dispersion). Do not mix with alkaline degreasers — the acid-base reaction neutralises both products, wastes chemistry, and can gel in spray systems. 4. Specialist Degreasers Electrical contact cleaners are fast-evaporating, non-conductive, residue-free solvents designed specifically for cleaning electrical and electronic components — motor windings, PCBs, switch contacts, connectors, relays, and switchgear. Products like CRC Contact Cleaner and WD-40 Specialist Electrical Contact Cleaner evaporate within seconds and leave no residue that could cause electrical tracking or short-circuit. They should never be applied to live high-voltage equipment. For de-energised, low-voltage equipment they are the correct product and safe to use. Do not substitute general-purpose solvent degreaser — the residue profile is completely different. Food-grade degreasers are formulated to NSF International standards (NSF A1 for incidental food contact; NSF A2 for no food contact) or equivalent under HACCP food safety plans. They are free of food-contact hazards, rinse cleanly and completely, and are mandatory in food processing and preparation environments where equipment contact with food ingredients is possible. Using a non-food-grade degreaser in a food processing environment is a food safety breach. Biodegradable / eco-safe degreasers are formulated to meet environmental regulations for low toxicity, rapid biodegradation, and low VOC content. They are required on sites with environmental certification (ISO 14001, green star), near waterways, on agricultural sites, and wherever stormwater contamination risk must be controlled. They are typically less aggressive than conventional options on heavy soiling, but adequate for regular maintenance cleaning. 5. Emulsion Degreasers Emulsion degreasers blend solvent and water-dispersible chemistry into a single product. They provide stronger solvency than a pure water-based product, rinse cleanly with water, and do not require the strict VOC controls of a pure solvent. Common in automotive workshops, manufacturing, and general industrial cleaning where heavy soiling and water rinsing need to coexist. The foaming, clinging versions are effective on vertical surfaces — equipment housings, machine frames, vehicle underbodies — where a spray-and-let-dwell approach is needed. Degreaser Selection Guide: 4 Questions to Ask First Getting the degreaser right before you reach for a product comes down to four questions. Answer these and the choice narrows quickly. 1. What is the contamination type? Heavy petroleum oils, greases, and hydraulic fluid — strong solvent or high-alkaline. Cutting oils and metalworking fluids — alkaline or emulsion. Carbon deposits and baked-on grease — high-alkaline with heat, or strong solvent. General maintenance contamination (machine oil, light grease, grime) — mildly alkaline or citrus. Biological contamination (food-based fats and oils) — food-grade alkaline. Electronic flux and residue — electrical contact cleaner. The contamination dictates the chemistry required. 2. What is the surface material? Steel and cast iron — all degreaser types are generally compatible, but rinse alkaline products quickly to prevent flash rust. Aluminium, copper, brass, zinc — avoid high-alkaline (pH 12+); use citrus, neutral-to-mildly-alkaline with inhibitors, or purpose-formulated solvent. Painted surfaces — avoid strong solvents and high concentration alkaline; mildly alkaline or citrus at proper dilution. Rubber and plastics — check product SDS; many solvents attack specific rubber compounds and thermoplastics. Concrete and sealed floors — alkaline or citrus with dwell time; solvent degreasers evaporate before they penetrate. 3. What is the application method? Aerosol or trigger spray (spot degreasing) — solvent aerosol or ready-to-use water-based trigger. Mop or brush (floors, large flat surfaces) — diluted alkaline concentrate. Parts washer tank (recirculating, heated) — purpose-formulated low-foaming alkaline concentrate with corrosion inhibitor. Ultrasonic bath — specific low-foaming aqueous chemistry. Immersion soak — alkaline concentrate or solvent depending on substrate. Pressure wash or automated cabinet — low-foam alkaline concentrate. 4. What are the environment and compliance requirements? Enclosed or poorly ventilated space — water-based is strongly preferred; solvent requires LEV (local exhaust ventilation) and RPE. Food processing area — food-grade certification mandatory. Flammable/explosive atmosphere — non-flammable water-based only; no solvents. Near stormwater or waterways — biodegradable formulation required. Sites with environmental ISO 14001 or green certification — low-VOC, low ecotoxicity formulations. Skin and hands in regular contact — water-based with skin-safe pH; solvent requires nitrile gloves. Scenario Best Degreaser Type Avoid Heavy machine oil on steel lathe components High-alkaline concentrate + heat, or strong solvent Citrus alone on very heavy loads Aluminium CNC parts after machining Mildly alkaline + inhibitor (pH 8–10), or citrus High-alkaline (pH 12+) — etches aluminium Conveyor chain before re-lubrication Citrus degreaser or aerosol solvent High-foam water-based in enclosed areas Workshop concrete floor Alkaline concentrate diluted 1:10, dwell 5–10 min, scrub Aerosol solvent — evaporates before penetrating Electrical switchgear (de-energised) Electrical contact cleaner Any water-based product Motor winding cleaning Electrical contact cleaner General solvent degreaser — residue risk Pre-welding surface prep (steel) Acetone, MEK, or purpose-formulated weld prep solvent Citrus (terpene residue affects weld quality) Parts washer (heated recirculating tank) Low-foam alkaline concentrate with corrosion inhibitor Standard spray degreaser — foams and blocks pumps Food processing equipment NSF-rated food-grade degreaser Any non-NSF-certified product Enclosed confined space Water-based alkaline Solvent without LEV + RPE — vapour accumulation risk Before adhesive or threadlocker application Acetone or MEK (solvent, fast-evaporating, residue-free) Water-based — moisture inhibits anaerobic cure Pre-paint surface prep Purpose-formulated panel wipe / wax and grease remover Citrus (residue) or highly alkaline (raises surface pH) Industrial Applications: Degreasing by Equipment Type Bearings and Shaft Assemblies Bearings removed for inspection or regrease should be degreased before assessment. For sealed and shielded bearings, use an aerosol solvent contact cleaner or purpose-formulated bearing wash to flush the old lubricant without damaging seals. Open bearings can be immersed in parts washer solution (alkaline concentrate) or solvent. After degreasing, dry thoroughly and repack with the correct grease before reinstallation — a degreased bearing that is assembled dry will fail within minutes under load. See the Industrial Lubricants Guide for grease selection after cleaning. Degreasing removes contamination — but it doesn't isolate a heat-related electrical fault. For workshop electronics diagnosis on intermittent ECU, motor controller or PCB faults, the companion technique is contrast cooling. See our freeze spray guide for the aerosol-cooling diagnostic procedure. Gearboxes and Drives External cleaning of gearbox housings: alkaline spray or citrus degreaser, brush agitation, rinse with clean water. Internal drain and flush: specialist gearbox flush oil (not degreaser — residual degreaser chemistry can react with gear lubricant and damage seals). For conveyor chains and drive chains, citrus or aerosol solvent with chain brush works well for removing built-up grit and old lubricant without the mess of alkaline flush. After cleaning, lubricate immediately — bare chain left degreased will begin surface corrosion within hours in a humid environment. Hydraulic Systems External cleaning of hydraulic fittings, cylinders, and manifolds: mildly alkaline water-based degreaser or citrus. Never allow water-based degreaser to enter hydraulic system internals — water contamination in hydraulic oil causes cavitation, corrosion, and microbial growth. Internal hydraulic system flushing requires dedicated hydraulic flush oils, not general degreasers. Before replacing hydraulic seals or fittings, clean the interface with a fast-evaporating solvent (isopropyl alcohol or acetone) to ensure the mating surface is residue-free for the new seal compound. Welding and Fabrication Prep Weld joint surfaces must be clean and free of oil, grease, paint, and coating before welding. Any residual contamination in the weld zone causes porosity, inclusion defects, and weakened weld integrity. The standard degreasing approach for weld prep is acetone or dedicated weld prep solvent wiped with clean lint-free cloth. Apply with clean cloths only — a rag contaminated with oil will redistribute rather than remove contamination. Avoid citrus-based products for weld prep — terpene residue affects arc stability and weld quality. See the MIG Welding Guide for full pre-weld preparation procedure. Workshop Floors and Machine Exteriors Workshop floor degreasing for routine maintenance: alkaline concentrate at 1:10 to 1:20 dilution, mop or floor scrubber, 5-minute dwell, scrub, rinse or wet-vac. For heavy oil spills on concrete, apply concentrate undiluted or at 1:5, allow 10–15 minute dwell, agitate with stiff brush, rinse. Multiple applications may be needed for long-standing oil contamination that has penetrated the concrete surface. Machine exterior cleaning: trigger spray diluted alkaline or citrus, cloth or brush wipe — do not allow water-based product to penetrate electrical enclosures, control panels, or motor vents. Before Adhesive or Threadlocker Application Surface preparation before adhesive application is not optional — it is the most critical factor in bond strength. For anaerobic threadlockers, retaining compounds, and pipe sealants (Loctite family), the standard prep is cleaning with acetone or isopropyl alcohol to remove all oil, grease, and moisture from the mating surfaces. Water-based degreasers leave a moisture film that inhibits the anaerobic cure mechanism. For structural epoxy and cyanoacrylate adhesives, the surface should be clean and dry — acetone or MEK wipe. For contact adhesives, light solvent or purpose-formulated cleaner. See the Industrial Adhesive Types Guide for full surface preparation by adhesive type. How to Use an Industrial Degreaser: Step-by-Step These steps apply to manual spray-and-wipe or spray-and-rinse degreasing — the most common method in workshop environments. Step 1: Read the SDS first. Before using any new degreaser, check the Safety Data Sheet. Confirm dilution ratio, surface compatibility, PPE required, first aid, and disposal requirements. Do not skip this step — the SDS is the reference document for safe use. Step 2: Select and prepare PPE. At minimum: nitrile chemical-resistant gloves; safety glasses or chemical splash goggles. For solvent-based products in enclosed spaces: add P2/OV respirator and ensure ventilation. For high-alkaline products: full arm coverage. See the Safety Glasses Guide and Respirator Guide for PPE selection. Step 3: Prepare the surface. Remove loose debris, swarf, and gross contamination with a brush, cloth, or air blast before applying degreaser. Applying degreaser to a heavily fouled surface loaded with swarf and grit wastes product and results in poor cleaning. Remove what you can mechanically first. Step 4: Apply at correct dilution. For concentrated products, dilute as specified in the SDS. General dilution guide: heavy soiling 1:5 to 1:8; medium 1:10 to 1:15; light maintenance 1:20 to 1:30. Apply degreaser to the surface — spray, brush, or cloth wipe depending on area size and access. Step 5: Allow dwell time. Do not wipe immediately. Allow the degreaser to work: 30–60 seconds for light soiling; 3–5 minutes for medium; 10–15 minutes for heavy, baked-on contamination. Do not allow the degreaser to dry on the surface. If it begins to dry before you are ready to wipe/rinse, reapply to keep the surface wet. Step 6: Agitate if needed. For stubborn contamination, agitate with a brush, scouring pad, or cloth during the dwell period. Mechanical action combined with chemistry always cleans faster than chemistry alone. Step 7: Rinse or wipe. Water-based degreasers: rinse thoroughly with clean water. On ferrous metals, follow immediately with a dry cloth — do not allow water to sit. Solvent-based: wipe with clean lint-free cloth. Discard contaminated cloths promptly — do not re-use a cloth that has picked up contamination on a clean surface. Step 8: Inspect and re-apply if needed. Check that contamination has been removed. For critical applications (adhesive bonding, welding prep, bearing reassembly), a final wipe with clean acetone or IPA on a fresh cloth is good practice — the cloth should come away white or clean. Surface Compatibility Quick Reference Surface Solvent (Petroleum) High-Alkaline (pH 12+) Mildly Alkaline (pH 8–11) Citrus/Bio Electrical Contact Cleaner Carbon steel / cast iron ✅ Safe ✅ Safe — rinse quickly ✅ Safe ✅ Safe ✅ Safe Stainless steel ✅ Safe ✅ Safe ✅ Safe ✅ Safe ✅ Safe Aluminium ✅ Safe (most) ⚠️ NOT SAFE — etches ✅ Safe with inhibitors ✅ Safe ✅ Safe Copper / brass ✅ Safe ⚠️ Risk of tarnish/etch ⚠️ Check inhibitors ✅ Safe ✅ Safe Painted surfaces ⚠️ Strong solvents strip paint ⚠️ Concentrated alkaline strips paint ✅ Safe at correct dilution ✅ Safe diluted ⚠️ May soften some paints Rubber seals / gaskets ⚠️ May swell or degrade ✅ Generally safe ✅ Generally safe ⚠️ Check SDS ⚠️ Check SDS — some damage rubber Hard plastics (ABS, nylon) ⚠️ Many solvents attack plastics ✅ Generally safe ✅ Generally safe ✅ Generally safe ✅ Fast-evaporating = generally safe Polycarbonate ❌ Solvents craze/crack ✅ Safe ✅ Safe ✅ Safe ⚠️ Check SDS Concrete floors ⚠️ Evaporates before penetrating ✅ Best option ✅ Effective ✅ Effective Not applicable Glass ✅ Safe (avoid silicate-containing) ⚠️ Silicate-based alkaline etches glass ✅ Silicate-free only ✅ Safe ✅ Safe Electrical components ⚠️ Residue risk ❌ Conductive when wet ❌ Conductive when wet ❌ Residue risk ✅ Purpose-designed — use this This table provides general guidance only. Always check the SDS for the specific product and substrate. Spot test on a non-critical area when using an unfamiliar product on a new surface. Australian WHS Requirements and VOC Compliance Industrial degreasers — particularly solvent-based formulations — are regulated under Australian work health and safety law and the National Pollutant Inventory. Understanding your obligations is not optional for any PCBU (person conducting a business or undertaking) whose workers use these products. Workplace Exposure Standards (WES) Safe Work Australia's Workplace Exposure Standards for Airborne Contaminants (current edition) sets legally binding time-weighted average (TWA) and short-term exposure limit (STEL) concentrations for common solvent components. Relevant standards for common degreaser solvents include: Mineral spirits / white spirit: TWA 792 mg/m³ (100 ppm). Acetone: TWA 1,187 mg/m³ (500 ppm); STEL 2,374 mg/m³. Isopropyl alcohol (IPA): TWA 983 mg/m³ (400 ppm); STEL 1,230 mg/m³. Xylene: TWA 350 mg/m³ (80 ppm); STEL 655 mg/m³. n-Hexane: TWA 72 mg/m³ (20 ppm) — very low limit; check products containing hexane carefully. Trichloroethylene (TCE): TWA 54 mg/m³ (10 ppm) + biological monitoring required. These limits apply to the 8-hour average airborne concentration for exposed workers. If your degreasing operation involves frequent or prolonged solvent use in enclosed or poorly ventilated spaces, you may be required to conduct air monitoring to verify compliance. The hierarchy of controls applies: if you can substitute to a water-based product, do so before relying on engineering controls and PPE. Safe Handling Requirements Under the model WHS Act, you must provide workers with current SDS for all hazardous chemicals in the workplace, ensure appropriate training in safe use, store chemicals appropriately (including flammable storage cabinets for flammable solvents), and maintain a register of hazardous chemicals. SDS documents must be accessible to workers — not just filed away. Many operations move these to shared digital folders accessible from mobile devices on the floor. VOC Regulations and Environmental Obligations Volatile organic compounds (VOCs) from solvent degreasers are regulated under state EPA legislation and the National Environment Protection (NEPM) for ambient air quality. Large solvent users may be required to report to the National Pollutant Inventory (NPI). Wastewater from water-based degreasing operations typically requires trade waste disposal via a licensed contractor — contaminated degreaser solution cannot be discharged to stormwater drains. Check your local council requirements for trade waste approval before setting up any large-scale aqueous degreasing operation. Flammable Storage Flammable solvent degreasers must be stored in approved flammable storage cabinets under AS 1940:2017 (The storage and handling of flammable and combustible liquids). Compliance is a legal requirement for commercial and industrial premises. Quantities above threshold limits require licensed storage. Aerosol cans are also classified as flammable goods. Do not store solvent degreasers in standard shelving or near ignition sources. PPE for Degreaser Use PPE selection for degreasers depends on the specific product — always refer to the SDS. The following is a practical baseline guide: All industrial degreasers: Chemical-resistant gloves (nitrile is suitable for most formulations — check SDS for exceptions); safety glasses or chemical splash goggles. See the Safety Glasses Guide for splash rating guidance. Closed-toe safety boots. See the Safety Boots Guide for appropriate footwear in chemical environments. High-alkaline products: Add forearm protection (chemical-resistant sleeves or long nitrile gloves). High-alkaline concentrates cause serious chemical burns — skin contact must be prevented, not just minimised. End-of-shift hand washing should use a workshop-grade industrial hand cleaner with skin-conditioning ingredients (not dish soap or solvent rinse); see the Hand Cleaner Guide for formulation selection and barrier cream workflow. Solvent products in enclosed or poorly ventilated spaces: Add respiratory protection — at minimum a half-face respirator with OV/P2 combination cartridge to address both vapour and particulate hazards. Ensure the area is ventilated (cross-ventilation, LEV, or extraction fans) before starting. See the Respirator Guide for cartridge selection by hazard type. Aerosol sprays: Even in ventilated spaces, eye and skin protection is required. Aerosols create fine mist that travels — protect eyes even for short applications. Dilution and Dwell Time Reference Application Dilution Ratio Dwell Time Notes Light maintenance cleaning (machine exteriors, bench tops) 1:20 to 1:30 30–60 sec Wipe clean; no rinsing needed at this dilution for most products General workshop degreasing 1:10 to 1:15 2–5 min Agitate with brush for better penetration Heavy engineering soiling (machine oil, cutting fluid) 1:5 to 1:8 5–10 min May need multiple applications on very heavy contamination Workshop floor (oil spill on concrete) 1:5 undiluted 10–15 min Stiff brush, follow with rinse or wet-vac Parts washer (heated recirculating tank) 1:10 to 1:20 per manufacturer 5–20 min at 50–65°C Low-foam concentrate formulated for parts washers only Ultrasonic bath Per product spec 5–15 min Use purpose-formulated ultrasonic cleaning fluid only Pre-adhesive / pre-weld final wipe Ready-to-use solvent (acetone, IPA) Wipe, allow 30 sec evaporation Final wipe should transfer nothing to the cloth Disposal of Used Degreaser and Contaminated Rags Disposal is not the last item on the checklist to be dealt with whenever — it has legal and safety implications that should be part of your degreasing procedure from day one. Water-based degreaser solution (used, emulsified with oil): Cannot be discharged to stormwater. Most local councils require licensed trade waste disposal for oily water. Contact your local council for trade waste approval requirements. Small quantities of very dilute solution may qualify for sewer disposal with approval, but emulsified oil content makes this unlikely for used parts washer fluid. Solvent waste: Classified as hazardous waste under state EPA regulations. Must be collected by a licensed liquid waste contractor. Do not pour solvent waste into general waste bins, sewer, or stormwater. Accumulate in sealed, labelled containers as per your hazardous waste management plan. Contaminated rags — solvent-soaked: Spontaneous combustion is a documented and serious risk with oil-soaked rags, particularly those containing linseed oil or drying agents. Best practice: store used rags in a sealed metal bin partially filled with water, and empty daily. Dispose via licensed hazardous waste contractor. Do not place solvent-soaked rags in open bins, plastic bags, or in piles. Aerosol cans (empty): Puncture and recycle as scrap metal, or dispose via your local council's scheduled waste collection. Do not incinerate. Frequently Asked Questions What is an industrial degreaser and how is it different from a household cleaner? An industrial degreaser is a concentrated chemical cleaning agent formulated to break down heavy hydrocarbon contamination — machine oils, cutting fluids, grease, carbon deposits, and hydraulic oil — in commercial and industrial environments. Unlike household cleaners, which are dilute and pH-neutral, industrial degreasers are engineered for high-volume soiling, hard surfaces, and continuous use. They are available in much higher concentrations, with specific chemistries matched to application type. Some industrial formulations are also regulated as hazardous chemicals under Australian WHS law — household cleaners are not. What are the main types of industrial degreaser? The five main types used in Australian industry are: (1) solvent-based degreasers — dissolve hydrocarbon contamination using organic solvents such as petroleum spirits, ketones, or engineered blends; (2) water-based alkaline degreasers — emulsify oil using surfactants and alkaline builders, non-flammable and suitable for large-volume use; (3) citrus/bio-solvent degreasers — use d-limonene from citrus peel, biodegradable and water-dispersible; (4) specialist degreasers — including electrical contact cleaners and food-grade formulations; and (5) emulsion degreasers — combine solvent solvency with water-rinseable chemistry. What is the difference between a solvent degreaser and a water-based degreaser? Solvent degreasers dissolve grease chemically — solvent molecules break apart hydrocarbon chains and carry them away on evaporation. They are fast, residue-free, and effective on heavy petroleum soiling, but carry VOC and flammability risks and require careful WHS management. Water-based degreasers use surfactants to emulsify grease into microscopic droplets suspended in water, which are rinsed away. They are safer, less flammable, and better for environmental compliance, but require rinsing and may need heat to be effective on heavy oil loads. When should I use a solvent degreaser instead of a water-based one? Use a solvent-based degreaser when: you need fast, residue-free cleaning where moisture cannot be tolerated (electronics, sealed bearings, precision assemblies, pre-weld prep, pre-adhesive surfaces); there is no facility for rinsing; you are cleaning components that would rust immediately if wetted; or you are dealing with extremely heavy petroleum contamination that water-based products cannot shift efficiently. Use water-based for large-surface cleaning, floor maintenance, parts washers, food processing areas, any confined space where solvent vapour accumulation is a risk, and wherever VOC compliance is a concern. Is a degreaser the same as parts washer fluid? Not exactly. Parts washer fluid is a specific type of degreaser formulated for use in recirculating parts washing systems — heated tanks, spray-wash cabinets, or immersion units. It must be low-foaming to prevent flooding spray systems, contain corrosion inhibitors to protect ferrous parts between wash cycles, and remain stable over multiple uses before disposal. Standard spray degreasers are single-application products not designed for recirculating systems. Using a standard degreaser concentrate in a parts washer will produce excessive foam that can flood the system and degrade cleaning performance. Always use a concentrate labelled specifically for parts washer use. Can I use an industrial degreaser on aluminium? Some can, some cannot. High-alkaline formulations (pH above 12) react with aluminium, causing etching, pitting, discolouration and surface degradation — even a brief contact time can cause permanent damage to precision aluminium components. Citrus-based degreasers, neutral-to-mildly-alkaline formulations with corrosion inhibitors (pH 8–10), and most petroleum solvents are safe on aluminium. Always check the SDS for surface compatibility, look for explicit "safe on aluminium" labelling, and spot-test on a non-critical area if using an unfamiliar product on aluminium. Is industrial degreaser safe on painted surfaces? It depends on the product and the paint. Strong solvents (acetone, MEK, xylene-based formulations) will strip or soften most paints. High-alkaline concentrates at full or near-full strength can lift paint from metal. Mildly alkaline water-based degreasers at correct dilution (1:10 or greater) are generally safe on factory-applied industrial coatings. Citrus degreasers at recommended dilution are typically paint-safe. As a rule, avoid prolonged dwell time on any painted surface regardless of chemistry, and always spot-test on an inconspicuous area first. If the purpose is to remove paint, use a purpose-formulated paint stripper rather than a degreaser. What dilution ratio should I use for an industrial degreaser? Dilution depends on the product and the severity of contamination. As a general working guide: light maintenance cleaning — 1:20 to 1:30 (1 part concentrate to 20–30 parts water); medium workshop degreasing — 1:10 to 1:15; heavy soiling and engineering contamination — 1:5 to 1:8; floor cleaning with oil spills — 1:5 to neat. Always follow the manufacturer's SDS — over-dilution reduces effectiveness and wastes labour on multiple passes, while under-dilution wastes product and increases WHS risk. Heated application allows more dilute solutions to achieve the same result as concentrated cold solution. What is dwell time and why does it matter for degreasing? Dwell time is the period you allow a degreaser to remain in contact with the contaminated surface before rinsing or wiping. The chemistry needs contact time to penetrate and emulsify the contamination. Too short a dwell time means you are wiping the surface before the product has done its job, requiring more product and more scrubbing. Typical dwell times: 30–60 seconds for light soiling; 3–5 minutes for medium; 10–15 minutes for heavy deposits. Do not allow the degreaser to dry on the surface — dried degreaser leaves residue and requires a second application. If the product starts to dry during dwell time, reapply to keep the surface wet. What PPE do I need when using industrial degreasers in Australia? PPE must be selected based on the SDS for the specific product. Minimum baseline for most industrial degreasers: chemical-resistant nitrile gloves, safety glasses or chemical splash goggles, and closed-toe footwear. High-alkaline products add full arm coverage and face shield for splash risk. Solvent-based products used in enclosed or poorly ventilated spaces require respiratory protection — a half-face respirator with OV/P2 combination cartridge as a minimum — plus adequate ventilation. Check the SDS PPE section and the product hazard classification before use. Do not substitute latex gloves for nitrile where solvent resistance is required. What are the Australian WHS requirements for solvent degreasers? Under the model WHS Act and Safe Work Australia's Workplace Exposure Standards for Airborne Contaminants, PCBUs must assess solvent exposure risks, implement the hierarchy of controls (substitution to water-based chemistry preferred), and ensure airborne concentrations remain below the applicable TWA and STEL limits for solvent components. Specific obligations include: current SDS accessible for all hazardous chemicals; adequate ventilation or local exhaust extraction; PPE provision and training; flammable storage compliance under AS 1940:2017; and a hazardous chemicals register. Chlorinated solvents including TCE require biological monitoring for exposed workers. Can I use degreaser on electrical equipment? Standard industrial degreasers — both water-based and most solvent-based — should not be used on electrical equipment. Water-based products are conductive when wet and will cause short-circuits. Most general solvent degreasers leave a thin residue film. The correct product for electrical and electronic equipment is a purpose-formulated electrical contact cleaner — fast-evaporating, non-conductive, and residue-free. Products such as CRC Contact Cleaner or equivalent are designed for PCBs, connectors, switchgear, and motor windings. Never apply any product to live high-voltage equipment — always de-energise, lock-out/tag-out, and allow adequate discharge time before cleaning any electrical component. What is a food-grade degreaser? A food-grade degreaser is formulated to meet NSF International standards — or equivalent under HACCP food safety programs — for use in food processing and food preparation environments. NSF A1 designation covers incidental food contact; NSF A2 covers no food contact (cleaning between food production runs where residue would not contact food). Food-grade degreasers are free of food-contact hazards, rinse cleanly without leaving residue that could contaminate food, and are required under most food safety management systems for any equipment that contacts food ingredients. Using a non-food-grade degreaser in a food processing environment is a food safety compliance breach regardless of how well the surface is rinsed. How do I safely dispose of used degreaser and contaminated rags? Disposal requirements depend on the formulation. Used water-based degreaser solution emulsified with oil cannot be discharged to stormwater — it requires licensed trade waste disposal; check your local council requirements. Solvent waste is classified as hazardous waste under state EPA regulations and must be collected by a licensed liquid waste contractor. Solvent-soaked rags carry spontaneous combustion risk — store in a sealed metal bin partially filled with water, and empty daily via licensed waste disposal. Do not place solvent rags in open bins or plastic bags. Always refer to the product SDS for specific disposal instructions. Is WD-40 a degreaser? WD-40 original formula is primarily a water-displacing lubricant and corrosion inhibitor — not a degreaser. It contains a light petroleum distillate carrier that can loosen light contamination, but it leaves an oily residue. Using WD-40 original formula to degrease a surface before lubrication, adhesive, or welding is counterproductive — you are adding a lubricant film, not removing one. WD-40 Specialist Degreaser is a different product — a purpose-formulated water-based degreaser with no residue — and is appropriate for degreasing. Read the label carefully. The original blue-and-yellow WD-40 can is not a degreaser. Pair this with our Loctite Application Guide for thread locker selection, fixture and cure times. For Australian hard hat standards, colours and AS/NZS 1801 compliance, see our Hard Hat Guide Australia. AIMS Industrial stocks grease couplers — see the full range for trade and industrial use. Need grease nipples? Browse the AIMS range at grease nipples.What is the difference between an emulsifying and a non-emulsifying degreaser? An emulsifying degreaser mixes the oil and grease into the water so it rinses away together — good for general cleaning through a drain-interceptor system. A non-emulsifying (splitting) degreaser lets the oil separate back out so it can be skimmed and the water reused or disposed of correctly — preferred where an oil-water separator or trade-waste rules apply. Match it to how the site handles waste water. See the degreasers range. How should I apply an industrial degreaser? The method suits the job: spray-on and wipe for light surface grease, soak or immerse for heavily fouled parts, brush or agitate to lift baked-on deposits, and pressure-wash rinse for large equipment. Always give the degreaser its dwell time before agitating or rinsing. For immersion cleaning of parts, a dedicated bath is better — see our parts washer guide. Are industrial degreasers flammable? It depends on the type. Solvent degreasers can be flammable or combustible and carry a flash point — store and use them away from ignition sources with good ventilation. Water-based (aqueous) degreasers are generally non-flammable, which is one reason they're preferred in hot or enclosed workshops. Check the product's safety data sheet for the flash point and handling class. See the wider cleaning chemicals range and CRC.
Read moreIndustrial Adhesive Types: Complete Guide
Industrial adhesive types: contact adhesive, epoxy, cyanoacrylate, anaerobic threadlockers, structural acrylic, RTV silicone and MS polymer — selection guide for Australian industry.
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Purple low-strength threadlocker for fasteners under 6mm. Cure times, breakaway torque, 222 vs 243, Activator 7471 for inactive metals, and the 222MS Mil-Spec variant — explained.
Read moreLoctite 577 Thread Sealant Guide
Threaded pipe joints fail for two reasons: the wrong sealant or no sealant at all. PTFE tape shreds, bunches, and leaves installer skill as the critical variable. Old pipe dope shrinks over time. Loctite 577 eliminates both problems — it's an anaerobic thread sealant that cures into a solid polymer seal inside the thread void, filling gaps completely without shredding, creeping, or hardening. This guide covers everything you need to apply Loctite 577 correctly: what it is, how it cures, cure times, the full Loctite thread sealant comparison table, fluid and media compatibility, when you need an activator, and the mistakes that cause failures. Whether you're sealing compressed air fittings, hydraulic lines, water pipe, or gas — this is the reference guide. Loctite Thread Sealant Comparison Guide — Quick Reference Henkel makes five standard thread sealants in their Loctite range, each targeting a specific thread type, application, or substrate. Choosing the wrong product for the application is the most common purchasing mistake. Product Strength Viscosity Best Application Thread Types Temp Range Stainless Steel AIMS Product Loctite 542 Medium Low (liquid) Fine metric and BSP hydraulic / pneumatic instrument connections — M6 to M36 Fine metric, small BSP -55°C to +150°C Slow without activator View 542 Loctite 565 Low–Medium Paste General-purpose all-metal pipe fittings; low-pressure water, air, general plumbing BSPT, NPT, metric parallel -55°C to +150°C Acceptable View 565 Loctite 577 Medium Thixotropic paste General-purpose metal fittings; compressed air, hydraulics, water, gas, high-pressure lines up to 2" BSP / 400 bar BSPT, NPT, BSPP, metric -55°C to +150°C Good (activator for fastest cure) View 577 Loctite 567 Low–Medium Low (liquid) Stainless steel, copper, and passive metal fittings; where lower strength and easier disassembly are preferred All pipe thread types -55°C to +200°C Excellent (engineered for SS) View 567 Loctite 569 High Paste High-strength hydraulic systems; permanent or semi-permanent sealing; fittings that must not back off under extreme pressure or vibration BSPT, NPT, metric parallel -55°C to +150°C Slow without activator View 569 What Is a Thread Sealant? A thread sealant fills the spiral gap between mating threaded pipe connections to prevent fluid or gas leaks. Unlike a threadlocker — which locks bolts and fasteners against vibration loosening — a thread sealant is specifically engineered for pipe and fitting threads, where the goal is pressure-tight sealing rather than torque retention. Loctite 577 anaerobic sealant is one option for BSP thread sealing — for flat-face fitting joints and reusable hydraulic connections, the mechanical alternative is the Dowty washer (bonded seal). See the Dowty washer and bonded seal guide for when to use each. The two words look similar enough to cause real purchasing mistakes. A threadlocker (Loctite 243, 270, 277) works on cylindrical bolt threads and cures to high shear strength. A thread sealant (Loctite 577, 567, 542) works on tapered and parallel pipe threads and cures to fill the helical void, blocking fluid passage. The products are not interchangeable — using a threadlocker on pipe threads gives poor sealing; using a thread sealant on bolts gives inadequate locking strength. Anaerobic thread sealants like Loctite 577 cure when two conditions are met: contact with metal ions (the catalyst) and exclusion of oxygen (the inhibitor is removed). Outside the joint, exposed to air, they remain liquid indefinitely — which is why excess sealant on the outside of a fitting stays wet long after the joint has cured internally. This is by design, not a failure. See the FAQ section for a full explanation of this common point of confusion. For a broader overview of thread locking and sealing products, see our Thread Locking & Sealing Guide and Loctite Threadlocker Selection Guide. What Is Loctite 577? Loctite 577 is a single-component, medium-strength, thixotropic anaerobic thread sealant designed for general-purpose sealing of metal pipe threads and fittings. Developed by Henkel, it is the direct replacement for traditional methods including PTFE tape, hemp/jointing compound, and liquid pipe dopes. Its thixotropic paste consistency is a deliberate engineering choice: it flows under the shear force of thread engagement but holds its position on vertical threads before assembly, preventing drip and run-off. This makes it far easier to control than thin liquid sealants on large-diameter or overhead fittings. Loctite 577 is approved for industrial and process water systems, natural gas and LPG, hydraulic fluid, diesel, compressed air, and notably for hydrogen gas up to 100% (KIWA GASTEC QA AR 214), making it one of the few commercially available thread sealants cleared for hydrogen fuel systems. Note that for potable (drinking) water connections, use Loctite 55 sealing cord — it carries NSF 61 certification; the anaerobic liquid sealants including 577 do not. Property Value Type Anaerobic, single component Colour Cream / off-white Viscosity Thixotropic paste (medium-high) Strength Medium — disassemble with hand tools Operating temperature -55°C to +150°C (short-term peak 200°C) Max thread size Up to 2-inch BSP Max gap fill 0.25–0.4 mm depending on substrate Max pressure (sealed) Up to 400 bar Fixture time (steel, 22°C) 10–60 minutes Full cure time 24 hours at 22°C Potable / drinking water Not NSF 61 certified — use Loctite 55 for drinking water Gas approval BS 6956 Type B; KIWA GASTEC QA AR 214 (incl. H₂) Sizes available 50 ml, 250 ml Thread Sealant vs PTFE Tape: Which Should You Use? PTFE tape (also called Teflon tape or plumber's tape) has been the default for pipe thread sealing for decades — but its dominance rests on familiarity and low cost, not technical superiority. For professional and industrial applications, anaerobic thread sealants like Loctite 577 address every key weakness of PTFE tape. Factor Loctite 577 PTFE Tape Shredding / contamination risk None — cures solid inside joint Can shred into valves, filters, pumps Hydraulic systems Approved ✓ Not recommended — fragments in fluid Vibration resistance Excellent — cured polymer resists loosening Poor — thread can back off under vibration Gap filling Up to 0.4 mm — fills worn or oversize threads Minimal — tape deforms but does not fill Application consistency High — same result every time Variable — depends on wrap technique and layers Minor oil contamination tolerance High — tolerates light surface contamination Low — contamination compromises wrap adhesion Disassembly Hand tools for medium strength Easy — unwind and re-tape Potable / drinking water Not NSF 61 certified — use Loctite 55 Loctite 55 cord is NSF 61 certified for drinking water Cost per joint Higher Lower Learning curve Low — apply to male thread, assemble Low — but more variable outcomes When PTFE tape is the right call: low-pressure domestic water fittings where cost matters most, or when sealing plastic-to-metal thread connections (anaerobic sealants are not suitable for most plastic threads — see Common Mistakes below). For everything else — hydraulic systems, compressed air, gas lines, or any application where contamination of the downstream fluid is unacceptable — Loctite 577 is the better technical choice. How to Apply Loctite 577 Correct application takes less than two minutes per fitting. The most common failures come from skipping the cleaning step or over-applying. Follow these six steps. Step 1 — Clean and degrease. Remove all oil, grease, old sealant, and loose particles from both male and female threads. Use Loctite SF 7070 Cleaner & Degreaser or another fast-evaporating industrial degreaser. Allow to dry fully — wet solvent residue will slow cure. This step is the one most often skipped, and the one most responsible for slow or failed cures. Step 2 — Inspect threads. Check threads for damage, burrs, or excessive wear. Loctite 577 will fill gaps up to 0.4 mm, but damaged threads that prevent proper assembly will reduce sealing performance. Re-cut or replace fittings with significant damage. Step 3 — Apply to male thread. Apply a 360° bead of Loctite 577 to the male thread, starting from the second or third thread (leaving the leading thread clear to prevent contamination of the downstream fluid). For coarser or larger threads, also apply to the female thread to ensure full void coverage. Force the material into the thread form — don't just coat the surface. Step 4 — Assemble immediately. Engage and tighten the fitting using hand or wrench torque in accordance with the fitting manufacturer's specification. Loctite 577 begins curing on contact with metal, so assemble promptly. You have a working time of approximately one hour from application to make any positional adjustments — after that the cured sealant begins to resist repositioning. Step 5 — Wipe excess. Clean any excess product from the outside of the fitting before cure. Excess sealant exposed to air will remain liquid indefinitely (this is normal — see the FAQs). Removing it now is easier than mechanical removal later. Step 6 — Wait before pressure testing. Allow the joint to reach fixture strength before applying line pressure. On steel at 22°C this takes 10–60 minutes. For full chemical resistance and maximum pressure rating, allow 24 hours before full service loading. In cold conditions (below 10°C) or on passive metals, use Loctite SF 7649 activator — see the primer section below. Cure Times Loctite 577 is an anaerobic product — cure rate depends on temperature, substrate reactivity, and gap size. The table below covers typical conditions on carbon steel at 22°C. Brass cures noticeably faster; stainless steel and aluminium slower. Stage Time (Steel, 22°C) What It Means Initial handling strength 10–60 minutes Joint holds position; not ready for pressure Low-pressure service 1–3 hours Suitable for static, low-pressure testing Full cure / full service 24 hours Full chemical resistance; rated pressure; full torque Condition Effect on Cure Solution Below 10°C Significantly slower — may take 48–72 hrs for full cure Use SF 7649 activator or bring assembly to room temp Brass / copper threads Faster — brass is highly reactive, near-instant initial seal No change needed Stainless steel Slower — passive oxide layer reduces metal ion activity Apply SF 7649 activator to female thread before assembly Aluminium / zinc / cadmium plating Slower — passive surfaces Apply SF 7649 activator Large gap (>0.25 mm) Slower on outer surface of gap Apply to both male and female threads; use activator Heavy contamination Can prevent cure or cause weak bond Degrease thoroughly with SF 7070 before application Important note on exposed excess: Sealant squeezed outside the joint and exposed to air will never cure — it will remain liquid or tacky indefinitely. This is the correct behaviour of an anaerobic product, not a sign of product failure. The joint itself, where sealant is trapped between metal threads with no air, cures normally. Loctite Thread Sealant Comparison Guide Henkel makes five standard thread sealants in their Loctite range, each targeting a specific thread type, application, or substrate. Choosing the wrong product for the application is the most common purchasing mistake. The table below compares all five by the criteria that matter in practice. Product Strength Viscosity Best Application Thread Types Temp Range Stainless Steel AIMS Product Loctite 542 Medium Low (liquid) Fine metric and BSP hydraulic / pneumatic instrument connections — M6 to M36 Fine metric, small BSP -55°C to +150°C Slow without activator View 542 Loctite 565 Low–Medium Paste General-purpose all-metal pipe fittings; low-pressure water, air, general plumbing BSPT, NPT, metric parallel -55°C to +150°C Acceptable View 565 Loctite 577 Medium Thixotropic paste General-purpose metal fittings; compressed air, hydraulics, water, gas, high-pressure lines up to 2" BSP / 400 bar BSPT, NPT, BSPP, metric -55°C to +150°C Good (activator for fastest cure) View 577 Loctite 567 Low–Medium Low (liquid) Stainless steel, copper, and passive metal fittings; where lower strength and easier disassembly are preferred All pipe thread types -55°C to +200°C Excellent (engineered for SS) View 567 Loctite 569 High Paste High-strength hydraulic systems; permanent or semi-permanent sealing; fittings that must not back off under extreme pressure or vibration BSPT, NPT, metric parallel -55°C to +150°C Slow without activator View 569 The most important distinction: if you're sealing bolt threads rather than pipe threads, you need a threadlocker (Loctite 243, 270, or similar), not a thread sealant. These are fundamentally different product types. See our Loctite Threadlocker Guide for bolt and fastener applications. 577 vs 567 — the question we get most: 577 is the higher-viscosity general workhorse for coarser BSP and NPT threads across all common industrial applications. 567 is lower viscosity, flows into finer thread forms, and is purpose-built for stainless steel and other passive metals where its PST (Pipeline Sealant Technology) chemistry provides faster, more reliable cure without an activator. If your fittings are predominantly stainless or copper, 567 is the better technical choice. If you're working across mixed metals in a general industrial or workshop environment, 577 covers more situations with one product. Fluid and Media Compatibility Loctite 577 has broad chemical resistance once cured, but there are application types it is not suited to. Check your specific fluid or gas against the table below before specifying. Fluid / Media Loctite 577 Compatible? Notes Compressed air ✓ Yes Standard application; widely used in workshop and industrial systems Water — industrial / process ✓ Yes Industrial and process water systems; not NSF 61 certified — use Loctite 55 cord for potable/drinking water lines Steam (below 120°C) ✓ Yes Within -55°C to +150°C rating; verify system temp Natural gas / LPG ✓ Yes BS 6956 Type B approved Hydrogen gas (up to 100%) ✓ Yes KIWA GASTEC QA AR 214 — one of few sealants cleared for H₂ systems Diesel fuel ✓ Yes Good fuel resistance once fully cured Petrol / gasoline ✓ Yes Fuel resistant once cured; allow 24-hour full cure before exposure Hydraulic oil (mineral) ✓ Yes Standard use; preferred over PTFE tape for hydraulic BSP threads Synthetic hydraulic fluid ✓ Yes Check specific fluid data sheet for extreme chemistries Coolant / antifreeze ✓ Yes Suitable for cooling system fittings Refrigerant (R410A, R32, R134a) ✗ No Not rated for refrigerants — use Loctite 554 or approved refrigerant-grade sealant Strong acids / oxidising agents ✗ No Anaerobic polymer is not acid-resistant; use PTFE or specialist chemical sealant Ketones (MEK, acetone) ✗ No Solvents attack cured polymer Chlorinated solvents ✗ No Not compatible — may cause seal degradation Passive Metals and When You Need an Activator Anaerobic thread sealants cure through a reaction catalysed by metal ions. Active metals — iron, steel, copper, brass — release ions freely and drive a fast, complete cure. Passive metals — stainless steel, aluminium, zinc, cadmium plating, titanium — have oxide layers that slow or inhibit the metal ion release, resulting in slow or incomplete cure, particularly on larger gap sizes. Loctite 577 is formulated to tolerate stainless steel without an activator for smaller gaps (under 0.25 mm) and at room temperature. But in practice, for reliable, predictable cure on stainless, aluminium, or plated fittings — particularly in cold conditions or where the fitting may be under pressure before 24 hours — using Loctite SF 7649 activator is the correct procedure. Apply SF 7649 to the female thread as a thin film and allow 1–2 minutes for the solvent carrier to evaporate before applying Loctite 577 to the male thread and assembling. The activator provides the metal ion catalyst externally, accelerating cure to near the same rate as on active steel. It also overcomes cure issues in cold environments below 10°C. Do not apply activator directly over the wet sealant — it is a pre-treatment for the mating surface, not a post-cure accelerant. Common Mistakes to Avoid Most Loctite 577 failures trace back to one of these six errors: 1. Skipping the cleaning step. The most common cause of slow or failed cure. Even light oil film on threads from machining or handling reduces metal ion availability. Clean with SF 7070 or a solvent cleaner and allow to fully dry before applying sealant. Wet threads or residual solvent both impair cure. 2. Using on plastic or non-metallic fittings. Anaerobic sealants are formulated for metal-to-metal thread engagement. On plastic threads — nylon, PVC, PVDF, polypropylene — Loctite 577 will not cure reliably (no metal ion catalyst) and can cause stress cracking in certain thermoplastics. For plastic-to-plastic or plastic-to-metal threads, use PTFE tape or a purpose-built plastic pipe sealant such as Loctite 5331. 3. Applying too much product. More is not better. A thin, continuous 360° bead on the male thread is all that is needed. Excess product is squeezed outside the joint on assembly and remains liquid permanently (anaerobic — exposed to air). It doesn't improve sealing and creates a mess. The actual seal is formed by the product trapped inside the thread void. 4. Pressurising before adequate cure. Applying full line pressure before the sealant has reached fixture strength forces uncured product out of the joint and can wash away the seal. On steel at 22°C, wait at least one hour before low-pressure testing and 24 hours before full-rated pressure. In cold conditions, wait longer or use activator. 5. Ignoring passive metal cure speed. Fitting stainless steel, aluminium, or plated fittings and expecting the same cure profile as carbon steel fittings is a setup for callbacks. On stainless without activator, fixture time can be several hours and full cure can take 48–72 hours. Use SF 7649 activator on passive metals as standard practice, not as an afterthought. 6. Combining with PTFE tape. A common field workaround — "belt and braces" thinking — that actually undermines both products. PTFE tape prevents the metal-to-metal contact needed for anaerobic cure. Either use 577 or use tape. Never both on the same fitting. Removing Loctite 577 Loctite 577's medium-strength cure means disassembly is straightforward in most cases. Unlike high-strength products like Loctite 569, you generally don't need heat to break the joint. Before full cure (within 24 hours): Disassemble with standard hand tools or a wrench. The partially cured polymer breaks cleanly. Clean threads with a solvent or wire brush before re-sealing. After full cure (24+ hours): Apply a standard pipe wrench or adjustable spanner. Medium-strength cured product will break free with normal torque. For stubborn joints or in situations where you need to avoid thread damage (e.g., brass or aluminium fittings), apply localised heat with a heat gun or small propane torch to 150–200°C. This softens the polymer and allows disassembly with minimal torque. Cleaning after removal: Wire brush, nylon brush, or a clean rag with solvent (acetone or SF 7070) removes residual product from threads. Allow to dry before applying fresh sealant. Do not re-use degraded or contaminated sealant from the old joint — apply fresh product. Loctite 577 is an anaerobic pipe thread sealant — one of several adhesive product types used in Australian industrial maintenance. For a complete guide to all industrial adhesive types including anaerobic threadlockers, retaining compounds, epoxy, contact adhesive, and RTV silicone, see the Industrial Adhesive Types Guide. Frequently Asked Questions What is Loctite 577 used for? Loctite 577 is used for sealing metal pipe threads and fittings against leaks in compressed air, hydraulic, water, gas, diesel, and steam systems. It replaces PTFE tape and traditional pipe dope by curing into a solid polymer seal inside the thread void. It is not a threadlocker and should not be used on bolt or fastener threads. How long does Loctite 577 take to cure? On carbon steel at 22°C: initial handling strength in 10–60 minutes, suitable for low-pressure testing after 1–3 hours, full cure and full rated pressure after 24 hours. Brass cures faster; stainless steel and aluminium slower. In cold conditions (below 10°C) or on passive metals, use Loctite SF 7649 activator to achieve practical cure times. What is the difference between Loctite 577 and 567? 577 is a thixotropic paste suited to coarser BSP and NPT threads in general industrial applications across all common metals. It is the standard workhorse for compressed air, water, hydraulic, and gas fittings. 567 is a lower-viscosity liquid that wicks into finer thread forms and is purpose-built for stainless steel and passive metals, where its PST chemistry delivers reliable cure without requiring an activator. If your installation is predominantly stainless steel or copper fittings, 567 is the better technical choice. For mixed-metal environments with larger threads, 577 covers more ground with one product. Is Loctite 577 suitable for fuel, gas, and water lines? Yes for industrial applications. Loctite 577 is approved for natural gas and LPG (BS 6956 Type B), hydrogen gas up to 100% (KIWA GASTEC QA AR 214), diesel, petrol, hydraulic oil, and industrial water and process water systems. It is not NSF 61 certified — for potable (drinking) water connections, use Loctite 55 sealing cord. It is also not suitable for refrigerants (R410A, R32, R134a) — use Loctite 554 for refrigerant line fittings. Is Loctite 577 removable? Yes. Loctite 577 is medium strength and designed for disassembly with standard hand tools in most cases. For very tight or long-cure joints, applying localised heat (150–200°C) softens the polymer and makes disassembly straightforward. This is distinct from high-strength thread sealants like Loctite 569, which require more effort to remove. What is the difference between a thread sealant and a threadlocker? A thread sealant (Loctite 577, 567, 542) seals pipe and fitting threads against fluid or gas leakage. A threadlocker (Loctite 243, 270, 277) locks bolts and fasteners against vibration-induced loosening. The chemistry is similar but the gap fill, strength, and application are different. Using the wrong type for the wrong application gives poor results — do not substitute one for the other. Is Loctite 577 better than PTFE tape? For most industrial, hydraulic, and professional applications: yes. Loctite 577 fills thread gaps completely, eliminates shredding contamination risk, tolerates minor oil contamination, and provides consistent results regardless of installer technique. PTFE tape is banned from hydraulic systems precisely because fragments cause damage to valves and pumps. For simple domestic water fittings where cost is the primary concern, PTFE tape remains practical. For anything involving hydraulic fluid, gas, or high pressure, use Loctite 577. Can Loctite 577 be used on stainless steel? Yes, with some qualification. Loctite 577 will cure on stainless steel, but more slowly than on carbon steel, because stainless steel's passive oxide layer reduces metal ion availability for the anaerobic cure reaction. For smaller gaps and normal temperatures, it cures adequately without an activator within 24 hours. For reliable, fast cure on stainless — particularly in cold conditions or where early pressure loading is required — apply Loctite SF 7649 activator to the female thread before assembly. Can Loctite 577 be used on plastic fittings? No. Anaerobic thread sealants require metal-to-metal thread contact to cure — plastic provides no metal ion catalyst. Loctite 577 will not cure reliably on plastic threads and can cause stress cracking in certain thermoplastics (particularly PVC, CPVC, and ABS). For plastic-to-plastic or plastic-to-metal connections, use PTFE tape or Loctite 5331 Plastic Pipe Sealant, which is specifically formulated for plastic thread systems. Why is excess Loctite 577 still wet after 24 hours? This is normal. Loctite 577 is an anaerobic product — it only cures when oxygen is excluded. Inside the joint, where sealant is trapped between metal thread surfaces with no air contact, curing proceeds normally. Outside the joint, exposed to air, the sealant remains liquid indefinitely. The wet exterior is not a sign of failure — the joint itself is cured. Wipe off the excess before it hardens into a difficult-to-remove skin. When do I need an activator with Loctite 577? Use Loctite SF 7649 activator when working with passive metals (stainless steel, aluminium, zinc, plated surfaces), in cold conditions below 10°C, when you need full cure in less than 24 hours, or when gap sizes exceed 0.25 mm on passive surfaces. Apply a thin film of activator to the female thread, allow the solvent carrier to evaporate for 1–2 minutes, then apply Loctite 577 to the male thread as normal and assemble. Do not apply activator over wet sealant. What Loctite thread sealant should I use for fine hydraulic threads? For fine metric or BSP hydraulic and pneumatic instrument connections (M6–M36 or small-bore hydraulic block fittings), use Loctite 542 — its low viscosity wicks cleanly into fine thread forms without over-filling. Loctite 577 is higher viscosity and better suited to coarser BSP and NPT threads up to 2-inch diameter. For general hydraulic fittings (3/8" BSP and above), 577 is the standard choice. Shop Loctite Thread Sealants AIMS Industrial stocks the full Loctite anaerobic thread sealant range in 50 ml and 250 ml sizes, including 542, 565, 567, 577, and 569 — with same-day despatch from our Milperra warehouse. If you're replacing PTFE tape or jointing compound across a facility, the Loctite thread sealant range covers every thread type, pressure rating, and substrate combination you'll encounter. Need help selecting the right product for your system? Our technical team at AIMS Industrial can advise on product selection for specific fluids, pressures, and substrate combinations — contact us directly or visit our Loctite Product Guide for further guidance. For related sealing applications, see our guides on RTV Silicone & Gasket Maker selection, Loctite 401 Instant Adhesive, and our Butterfly Valve Guide — Loctite 577 is the recommended thread sealant for BSP port connections on butterfly valve bodies and actuator assemblies. People Also Ask — Loctite 577 Thread Sealant Q: What is Loctite 577 used for? As this guide explains, Loctite 577 is an anaerobic thread sealant for metal pipe and fitting assemblies — including NPT, BSPT, and parallel thread fittings in hydraulic, pneumatic, water, and oil systems. It seals the thread form itself rather than spanning the bore, providing a leak-free joint that resists vibration loosening and can be disassembled with standard tools when required. Q: What is the difference between Loctite 577 and PTFE tape? Covered in this guide: PTFE tape is a mechanical gap-filler that can creep, extrude under pressure, and leave fragments in the system. Loctite 577 is a liquid that wicks into the thread helix, cures anaerobically in the absence of air, and bonds the joint chemically. It provides superior vibration resistance with no loose fragments. PTFE tape remains common for plumbing; Loctite 577 is preferred for precision industrial and hydraulic/pneumatic systems. Q: Is Loctite 577 suitable for gas pipe fittings? This guide addresses media compatibility directly: Loctite 577 is suitable for many gas applications, but always verify the product is appropriate for the specific gas, operating pressure, fitting material, and any applicable regulatory requirements for the installation. Some gas systems in Australia require products specifically approved for gas service. Refer to the current product TDS and relevant codes before use. Q: What surfaces is Loctite 577 compatible with? As covered in this guide, Loctite 577 performs on most active metals including steel, stainless steel, copper, and brass. On passive metals such as zinc, aluminium, and some stainless alloys, cure may be slower and an activator may be needed. The guide includes a full compatibility and activator reference for common substrate combinations encountered in industrial maintenance. Q: How does Loctite 577 compare to other Loctite thread sealants? This guide includes a full comparison table. Loctite 577 is a medium-strength sealant suited to general pipe assemblies. Loctite 567 is lower viscosity, designed for fine-pitch threads. Loctite 55 is a thread sealant cord rather than a liquid product. Loctite 572 is a slow-setting alternative with higher temperature resistance. Product selection depends on thread pitch, substrate, operating temperature, and whether disassembly will be required. For SmartWasher and benchtop parts washers, see the AIMS parts washer range. See AIMS's full high pressure fittings range — trade pricing and Australia-wide despatch.
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RTV Silicone Gasket Maker Guide: Application, Cure Time and Selecting the Right Product
What Is RTV Silicone? RTV stands for Room-Temperature Vulcanising — a family of silicone sealants and gasket makers that cure at ambient temperature by reacting with moisture in the air. Squeezed from a tube as a paste, RTV silicone forms a flexible rubber-like seal that bonds to metal, glass, ceramic and most plastics. Gasket maker grades are formulated specifically to seal between two mating flanges, replacing or supplementing a cut paper or rubber gasket. Don't confuse this with silicone spray — a different product entirely, despite the shared name. Silicone spray is an aerosol lubricant and release agent, not a gap-filling paste, and it doesn't cure into a gasket. See our Silicone Spray Guide if that's the product you're after. What's the difference between RTV silicone and an anaerobic gasket maker? RTV silicone cures in air (it needs moisture to set) and stays flexible. Anaerobic gasket makers — like Loctite 518 or 574 — cure only in the absence of air and in contact with metal, and form a harder, more rigid seal. RTV is more forgiving on uneven flanges and a wider material range; anaerobic suits precision machined metal-to-metal joints. Why are there so many colours? Colour codes the formulation. Black is general-purpose; red and copper are high-temperature; blue is medium-temperature/oil resistant; grey is sensor-safe (low-volatile, won't damage O2 sensors). Brand-by-brand the colour conventions vary — always check the manufacturer's data sheet rather than relying on colour alone. Pick up a bottle of RTV silicone gasket maker and the shelf next to it has five more — black, red, grey, blue, copper. Most people grab the one they recognise and hope for the best. This guide explains what each colour is for, when to use RTV versus a cut gasket or anaerobic flange sealant, and the one mistake that will kill your oxygen sensor within 48 hours of starting the engine. RTV Silicone vs Anaerobic Gasket Maker — What's the Difference? — Quick Reference Two fundamentally different sealing technologies share shelf space in the gasket maker category. Understanding the difference saves you from using the wrong one. Property RTV Silicone Gasket Maker Anaerobic Gasket Maker (e.g. Loctite 515, 518) Cure mechanism Atmospheric moisture Absence of air + metal ion catalyst Surface requirement Works on cast, rough, or uneven surfaces Requires close-fitting, machined metal surfaces Flexibility after cure Flexible rubber Rigid Oil/solvent resistance Excellent (oil, coolant) Excellent (oil, coolant, hydraulic fluid, solvents) Gap fill capability Up to 0.25–0.5 mm Typically <0.1–0.25 mm (grade dependent) Disassembly Bonds casing faces — harder to split Does not bond — easier to disassemble Best for Cast engine surfaces, flexible joints, general maintenance Precision-machined flanges on pumps, hydraulic systems, compressors Example products (AIMS) Loctite 596, 598, SI 587 Loctite 515, 518, 510, 5127, SI 5900 What Is RTV Silicone? RTV stands for Room Temperature Vulcanising. It describes a silicone polymer that cures — vulcanises — at room temperature by reacting with moisture in the air. No heat, no mixing, no UV light required. When you apply it as a bead, assemble the joint, and allow it to cure, it forms a custom-shaped, flexible rubber gasket bonded to both metal surfaces. The cure mechanism is straightforward: atmospheric moisture reacts with the acetoxy or alkoxy groups in the silicone polymer chain, crosslinking it into a solid rubber network. Acetoxy-cure RTV (the most common general-purpose type) releases acetic acid during cure — that's the vinegar smell. Alkoxy-cure RTV does not produce acetic acid, which is why it's typically sensor-safe. More on that below. For engine and gearbox sealing, "RTV silicone" and "gasket maker" are used interchangeably — but the products are specifically formulated for oil resistance, temperature cycling, and compression recovery that general-purpose silicones do not provide. Never use a bathroom or construction silicone sealant on an engine joint. What Is a Gasket Maker? A gasket maker is a silicone sealant product specifically formulated for automotive and industrial flange sealing — applied as a liquid bead that forms a gasket in place. The defining properties of a gasket-maker grade product, versus a general-purpose silicone, are: Continuous resistance to engine oil, coolant, and transmission fluid Defined temperature performance across a rated operating range Compression recovery — the ability to maintain a seal under sustained bolt load Adhesion to cast iron, aluminium, and steel without primer Flexibility sufficient to accommodate thermal expansion between dissimilar metals Gasket makers are used wherever a sealing joint must be formed or replaced on an engine, gearbox, differential, pump, or compressor — particularly where the OEM design calls for a liquid gasket rather than a cut gasket, or where resurfacing or wear has made a cut gasket impractical. RTV Gasket Maker vs Cut Gasket — Which Do You Need? The short answer depends entirely on what the OEM specifies for the joint in question. Use RTV gasket maker where: The OEM design calls for a liquid gasket — common on modern engine oil pans, rear main seal housings, timing covers, and differential covers on vehicles from the mid-1990s onward. Many of these joints have no cut gasket at all from the factory. Using a cut gasket on a face designed for RTV will often result in leaks because the joint clearance doesn't accommodate the additional thickness. Use a cut gasket where: The OEM specifies a formed gasket — head gaskets, exhaust manifold gaskets, intake manifold gaskets, water pump gaskets, and most carburettor base gaskets. These gaskets manage pressures and temperature ranges that RTV cannot. Never substitute RTV for a head gasket or any gasket subject to combustion pressure. Use both where: Some cut gaskets require RTV at specific points — typically at the corners where a one-piece gasket meets the block, or where end seals abut timing cover gaskets. The workshop manual will specify where to apply RTV as a supplemental sealant. Apply only at the directed points; applying RTV across the full face of a cut gasket is incorrect and can compress unevenly or cause gasket failure. Use a pre-formed industrial gasket where: The joint is a bolted raised-face flange on process piping, water service, or higher-pressure equipment. RTV silicone is not appropriate for these applications — the standard choice is a spiral wound gasket. See our Spiral Wound Gasket Guide for ASME B16.20 / AS 4087 selection, colour code, and installation. Never use RTV on a head gasket. Multi-layer steel (MLS) head gaskets, composite head gaskets, and fire-ring type head gaskets are precision-engineered components that must be replaced with OEM-equivalent parts. RTV will not withstand combustion pressure or the temperature differentials at the head/block interface. RTV Silicone vs Anaerobic Gasket Maker — What's the Difference? Two fundamentally different sealing technologies share shelf space in the gasket maker category. Understanding the difference saves you from using the wrong one. Property RTV Silicone Gasket Maker Anaerobic Gasket Maker (e.g. Loctite 515, 518) Cure mechanism Atmospheric moisture Absence of air + metal ion catalyst Surface requirement Works on cast, rough, or uneven surfaces Requires close-fitting, machined metal surfaces Flexibility after cure Flexible rubber Rigid Oil/solvent resistance Excellent (oil, coolant) Excellent (oil, coolant, hydraulic fluid, solvents) Gap fill capability Up to 0.25–0.5 mm Typically <0.1–0.25 mm (grade dependent) Disassembly Bonds casing faces — harder to split Does not bond — easier to disassemble Best for Cast engine surfaces, flexible joints, general maintenance Precision-machined flanges on pumps, hydraulic systems, compressors Example products (AIMS) Loctite 596, 598, SI 587 Loctite 515, 518, 510, 5127, SI 5900 Practical rule: If the mating surfaces are cast and slightly rough — engine blocks, gearbox housings, differential covers — use RTV silicone. If the surfaces are precision machined and flat — pump flanges, hydraulic manifolds, compressor housings — use an anaerobic flange sealant. If you're rebuilding the engine and the workshop manual calls for "gasket eliminator" at a specific joint, that's anaerobic. AIMS Industrial stocks both product types — see the full gasket sealant range for RTV and anaerobic options. For more on Loctite threadlockers and industrial adhesives, see our Loctite Threadlocker & Industrial Adhesives Guide. RTV Gasket Maker Colour Guide Colour is a convention — not a standard. Red from one brand has different specs than red from another. Use colour as a starting point for selection, then verify the specific product's temperature rating, oil resistance, and sensor-safe status before applying. Colour Typical Temp Range Key Properties Best Applications Avoid Black –54°C to +260°C Maximum oil resistance; flexible; designed for differential thermal expansion between dissimilar metals Oil pans, differential covers, transmission pans, timing covers, rocker covers with wide bolt patterns Joints near O2 sensors unless confirmed sensor-safe Red (High Temp) –50°C to +260°C (+343°C intermittent) High-temperature resistance; oil and coolant resistant; highly flexible High-heat applications: valve covers on turbocharged/high-performance engines, exhaust-adjacent flanges, coolant housings Joints near O2 sensors unless confirmed sensor-safe Blue –54°C to +204°C Commonly sensor-safe; flexible; oil and coolant resistant Valve covers, water pump housings, thermostat housings, general engine sealing where sensor safety is required High-temp applications above 200°C continuous Grey –54°C to +204°C Rigid after cure; high-torque applications; excellent for close bolt patterns; commonly sensor-safe Tight-tolerance flanges, intake manifold end seals, timing covers with close bolt patterns, rigid-joint applications Wide bolt pattern joints requiring flexibility Copper –54°C to +371°C Highest temperature rating; designed for continuous extreme-heat exposure Racing engines, turbocharged performance applications, exhaust manifold flanges, high-output engines Standard automotive applications (overkill — higher cost) Clear –57°C to +204°C General purpose; waterproof; not designed for continuous oil immersion HVAC, electrical sealing, non-engine general sealing Engine oil, coolant, or fuel immersion applications Gold / Silver –60°C to +300°C (grade dependent) General industrial and automotive use; mid-range temperature performance General flange sealing, heavy vehicles, workshop maintenance applications Always verify specific product TDS for oil resistance Colour ≠ brand standard. "Red" RTV from Loctite, Permatex, CRC, and Sanvo are all different products with different specifications. A Loctite 596 Red is rated to –50°C/+250°C and tested for the Loctite formulation. Always read the product label or TDS, not just the colour. Sensor-Safe RTV — Why It Matters This is the most important selection criterion for any engine sealed with modern emissions equipment — and the most commonly overlooked. Standard acetoxy-cure RTV silicones off-gas acetic acid and low levels of silicone vapour as they cure. In an open environment this is harmless. In an engine, any joint connected to the crankcase ventilation system — the oil pan, valve cover, timing cover, rear main seal housing — has a direct path to the intake manifold via the PCV (positive crankcase ventilation) system. When the engine runs, the PCV system draws crankcase vapours — including silicone off-gassing from freshly applied RTV — through the intake manifold. Those silicone vapours coat the heated sensing element of the oxygen (lambda) sensor. The sensor fails within 24–48 hours of the engine running, typically showing a rich mixture reading or a dead sensor signal. Replacement is the only fix. Sensor-safe RTV (alkoxy-cure type) does not produce these off-gases. Blue and grey grades are most commonly formulated as sensor-safe, but this is not universal. The product label will explicitly state "sensor safe" or "oxygen sensor safe." If it doesn't state this, assume it is not. If your engine has O2 sensors — which includes virtually every fuel-injected vehicle made since the late 1980s — use sensor-safe RTV on any joint connected to the crankcase. This applies to oil pans, valve covers, timing covers, and rear main seal housings without exception. How to Apply RTV Gasket Maker Correct application is straightforward, but the details matter. The most common causes of joint failure are contaminated surfaces, wrong bead size, and disturbing the assembly before the skin forms. Remove all old sealant and gasket material from both faces. Use a gasket scraper, plastic trim tool, or Loctite SF 790 gasket remover spray on stubborn residue. Any remaining material will create high spots that prevent even compression of the new bead and result in leaks. Degrease both mating surfaces. Wipe with isopropanol or brake cleaner and allow to dry completely. Oil or coolant residue on either face will prevent the RTV from bonding. Apply a continuous bead, 3–4 mm in diameter. Run the bead in a single, unbroken line around the entire sealing face. Go around bolt holes — not across them. Do not leave gaps. Do not apply multiple passes or a thick ridge. Assemble immediately. Once the bead is applied, you have a short open time — typically 10–15 minutes — before the skin begins to form. Assemble and hand-tighten fasteners before this window closes. Once the skin starts to form, the bead will not compress evenly. Torque fasteners in sequence. Follow the OEM torque sequence. Tightening fasteners in the wrong order can shift the uncured bead and create thin spots. Allow a minimum of 1 hour before adding oil or coolant. Allow 24 hours before starting the engine or pressurising the joint. In cold or low-humidity conditions, allow longer. Excess RTV entering the engine is a serious risk. A bead that is too thick squeezes inward when the joint is tightened. Once cured, that excess material can break off as a plug and circulate through the oil system — blocking the oil pickup screen, oil galleries, or hydraulic lash adjuster passages. 3–4 mm is sufficient. More is not better. Cure Time — What You Need to Know RTV gasket maker cures in stages. Understanding which stage is which prevents the most common timing mistakes. Stage Typical Time What It Means Tack-free skin 1–2 hours Surface is dry to the touch. Joint can be carefully handled but has no oil or pressure resistance. Add fluids 1 hour minimum Safe to add oil or coolant to the system. Do not pressurise. Full service cure 24 hours Full oil pressure and temperature resistance achieved. Safe to run the engine. Cure time is affected by temperature and humidity. Cold, dry conditions slow cure — in a cold workshop in winter, allow 36–48 hours before service. High humidity speeds the surface cure but does not significantly accelerate through-cure of thicker beads. A 3–4 mm bead at normal Australian workshop conditions (20–25°C, 50–60% RH) will typically achieve full cure in 24 hours. Fast-cure formulations are available — some rated for engine start within 4–6 hours — but check the specific product's TDS rather than assuming. The standard 24-hour rule applies unless stated otherwise. Common Mistakes and How to Fix Them Bead too thick Problem: Excess material squeezes inward when the joint is tightened, enters the engine interior, cures, breaks off, and circulates through the oil system. Can block the oil pickup screen, hydraulic lash adjusters, or oil galleries. Fix: 3–4 mm bead only. If you've already assembled with excess material, monitor oil pressure closely after first start and check the oil filter element for sealant fragments at the next oil change. Contaminated surface Problem: Oil, grease, or old sealant residue on either face prevents RTV from bonding. The bead looks correct but the joint leaks immediately under pressure. Fix: Strip both faces back to clean bare metal. Clean with isopropanol. Reapply. Wrong colour / non-sensor-safe product Problem: O2 sensor failure within 24–48 hours of first start. Typically presents as rich mixture fault codes, rough idle, or failed lambda sensor codes. Fix: Prevention only. If non-sensor-safe RTV has been applied to a crankcase joint, allow it to fully cure (7+ days) before running the engine — this reduces but does not eliminate off-gassing. In most cases the O2 sensor will still need replacement. Next time, use sensor-safe RTV. Assembling after skin has formed Problem: Delaying assembly past the open time allows the outer skin to cure. When the joint is tightened, the pre-skinned bead does not flow and bond evenly — creating thin spots and potential leak paths. Fix: Apply the bead and assemble immediately. Do not apply the sealant, leave it, then come back 20 minutes later. Running the engine before full cure Problem: Running the engine while the sealant is still partially cured allows oil pressure to wash out the uncured bead, leaving an immediate oil leak or causing sealant fragments to circulate. Fix: Wait the full 24 hours. If the job was urgent and the engine was started early, drop the oil and inspect the oil pickup screen and filter before running further. Using RTV on a head gasket application Problem: RTV will not withstand combustion pressure, exhaust temperatures, or the compression forces at the head/block interface. It will fail immediately. Fix: Replace with the correct engineered head gasket for the application. Application-Specific Selection Guide The table below summarises the correct product type and colour for the most common engine and drivetrain sealing applications. "Check OEM spec" means the correct product depends on the specific vehicle or machine — consult the workshop manual or service data before applying. Application Product Type Colour Key Notes Oil pan / sump RTV silicone gasket maker Black (preferred) or grey Use sensor-safe if fitted with O2 sensors; check OEM spec — many modern engines use RTV only Valve cover / rocker cover RTV silicone gasket maker Blue (sensor-safe) or grey Must be sensor-safe — direct path to PCV and O2 sensor. Often used to supplement a rubber valve cover gasket at corners Timing cover RTV silicone gasket maker Black or grey Use sensor-safe; typically used with or instead of a cut gasket depending on OEM spec Water pump housing RTV silicone gasket maker Blue or grey Coolant-resistant; sensor-safe preferred Thermostat housing RTV silicone gasket maker Blue or grey Coolant-resistant; sensor-safe preferred Differential cover RTV silicone gasket maker Black Maximum oil resistance; wide bolt pattern suits flexible black grade Transmission pan RTV silicone gasket maker Black or ATF-rated specific product Confirm oil type — some automatic transmission formulations specify a transmission-specific RTV grade Exhaust manifold (gasket supplement) High-temp RTV Copper or red Supplement only — never replace a cut exhaust manifold gasket with RTV alone Pump flanges (machined) Anaerobic flange sealant N/A (clear/blue liquid) Loctite 515, 518, or 5127 — precision machined faces only Hydraulic system flanges Anaerobic flange sealant N/A Loctite 510 or 518 for close-tolerance, high-pressure flanges Gearbox casing halves (machined) Anaerobic flange sealant N/A Anaerobic preferred where mating faces are precision machined; RTV silicone for rough-cast faces Industrial compressor flanges Anaerobic flange sealant N/A Loctite SI 5900 or 518 for rigid metal flanges For gear oil and lubricant selection when completing a differential or gearbox service, see our Gear Oil Guide: ISO VG Grades, EP Ratings & Gearbox Selection. Removing Cured RTV Silicone Cured RTV gasket maker is harder to remove than it looks. The approaches below work in sequence — start with mechanical, escalate to chemical if needed. Mechanical removal Use a flat plastic gasket scraper, a dedicated gasket scraper tool, or a razor blade held at a low angle. Avoid steel scrapers on aluminium faces — they will gouge the sealing surface and create leak paths. Work patiently across the full face. Most of the bulk sealant will come away mechanically. Gasket remover spray Products such as Loctite SF 790 (Chisel) or CRC Aerosol Gasket Stripper soften cured silicone and gasket material. Apply, allow to soak for 10–15 minutes, then scrape. Repeat for stubborn residue. Degrease thoroughly after stripping — gasket remover residue will contaminate the new sealant bond. Isopropanol or acetone (final clean) After mechanical and chemical removal, wipe both faces with isopropanol or acetone to remove all residue, oil film, and stripper chemical before applying new sealant. Allow to dry fully before applying RTV. RTV silicone is the right adhesive sealant for high-temperature, fuel-resistant, and flexible-bond applications — but it is not a structural adhesive and will not bond every substrate. For a complete comparison of industrial adhesive types including epoxy, anaerobic, cyanoacrylate, structural acrylic, and contact adhesive, see the Industrial Adhesive Types Guide. Frequently Asked Questions What is an RTV gasket maker? An RTV gasket maker is a single-component silicone sealant that you apply as a liquid bead, then assemble the joint before it cures — forming a custom-shaped rubber gasket in place between two mating surfaces. RTV stands for Room Temperature Vulcanising: the material polymerises (vulcanises) when exposed to atmospheric moisture at room temperature, without heat or mixing. The cured gasket is flexible, oil-resistant, and permanently bonded to both surfaces. RTV gasket makers are used throughout automotive, industrial, and mining maintenance wherever a sealing joint must be formed, replaced, or supplemented. Is RTV silicone the same as gasket maker? Not exactly, though the terms are often used interchangeably. All RTV silicone gasket makers are RTV silicones — but not all RTV silicones are gasket makers. General-purpose RTV silicone sealants (such as those used for plumbing, glazing, or HVAC) are the same chemistry but are not formulated for the oil resistance, temperature cycling, and compression recovery required in engine and gearbox sealing. Gasket-maker-grade RTV silicones are specifically compounded for automotive and industrial flange sealing — with defined oil resistance, temperature ratings, and gap-fill capability. When working on engines or gearboxes, always use a product labelled as a gasket maker or flange sealant, not a general-purpose silicone. What is the difference between silicone sealant and RTV silicone? Both are silicone polymers that cure at room temperature via moisture exposure, so they share the same fundamental chemistry. The difference is in formulation and performance specification. Standard silicone sealants (used in bathrooms, kitchens, and construction) are not designed for continuous oil, fuel, or coolant immersion, and are not rated for the temperature cycling of engine applications. RTV silicone — particularly gasket-maker grades — is compounded for oil and coolant resistance, defined temperature performance (typically –54°C to +260°C depending on grade), and the compression recovery needed to maintain a seal under bolt load. For any engine or gearbox sealing application, use RTV gasket-maker grade, not general-purpose silicone sealant. Which colour RTV gasket maker should I use? Colour is a general guide to temperature rating and oil resistance — not a specification. As a starting point: black for maximum oil resistance and flexible sealing of dissimilar metals (oil pans, differential covers); red for high-temperature applications above standard operating range (exhaust-adjacent, valve covers on high-heat engines); blue for general-purpose, sensor-safe sealing of moderate-temperature joints (valve covers, water pump housings); grey for rigid, high-torque joints with close bolt patterns (intake manifold end seals, timing covers); copper for extreme heat applications (racing, turbocharged engines). Always verify the specific temperature rating and oil-resistance spec of the product you select — colour conventions vary between manufacturers. Is a gasket maker as good as a real gasket? For many applications, yes — and some modern engines are designed from the factory with no cut gasket, relying entirely on RTV gasket maker for certain joints. Where the OEM design calls for RTV (common on oil pans, timing covers, and rear main seal housings on modern engines), using a cut gasket is incorrect. Where the OEM design specifies a cut gasket (such as a multi-layer steel head gasket, intake manifold gasket, or exhaust manifold gasket), the cut gasket must be replaced like-for-like — RTV is used only as a supplemental sealant at specific points if directed. Never use RTV gasket maker to replace a head gasket, exhaust gasket, or any gasket subject to combustion pressure. What is sensor-safe RTV, and when do I need it? Sensor-safe RTV is a formulation that does not off-gas acetic acid or silicone vapour during cure. Standard (non-sensor-safe) RTV silicones release low levels of silicone vapour as they cure. If used on engine joints connected to the crankcase ventilation system — such as valve covers, oil pans, or timing covers — that vapour is drawn through the PCV system into the intake manifold and coats the oxygen sensor. The sensor fails within 24–48 hours of the engine running. Any time you are sealing a joint on an engine fitted with oxygen sensors, use a sensor-safe RTV. Sensor-safe products are typically labelled explicitly, and blue and grey grades are most commonly sensor-safe — but always verify the product's description before applying. Can non-sensor-safe RTV silicone damage oxygen sensors? Yes. Standard RTV silicone formulations off-gas silicone vapour as they cure, particularly during the first few hours after assembly. On any engine joint connected to the crankcase — oil pans, valve covers, timing covers — that vapour is drawn through the crankcase ventilation (PCV) system and into the intake manifold. Silicone deposits on the oxygen sensor's sensing element cause incorrect readings or complete failure, typically within 24–48 hours of running the engine. This is a well-documented failure mode confirmed across multiple vehicle platforms. The fix is prevention: use only sensor-safe RTV on any joint connected to the crankcase. If non-sensor-safe RTV has been used, the oxygen sensor will likely need replacement after the sealant has fully cured and the engine has been run. What is the difference between RTV silicone and anaerobic gasket maker? RTV silicone gasket maker cures by reacting with atmospheric moisture — it works on all metal surfaces, cast surfaces, and even slightly uneven faces, and produces a flexible, rubber-like seal. Anaerobic gasket maker (such as Loctite 515, 518, or 510) cures only in the absence of air, between two close-fitting metal surfaces — it requires clean, machined metal-to-metal contact to cure properly and will not cure on rough cast surfaces or non-metallic substrates. Anaerobic products produce a rigid, solvent-resistant seal better suited to precision-machined flanges on pumps, hydraulic systems, and compressor housings. They are also easier to disassemble than RTV, which bonds casing faces together. Use RTV for flexible sealing of cast engine surfaces; use anaerobic for precision machined flanges requiring a thin, rigid, solvent-resistant seal. Do you have to wait 24 hours before running the engine after applying gasket maker? Yes, for most RTV silicone gasket makers. The surface of the sealant becomes tack-free within 1–2 hours, but the seal has not achieved full oil and pressure resistance. Running the engine before full cure — particularly under oil pressure — risks the uncured sealant washing out or failing to seal properly, and can cause excess material to break off and circulate through the oil system. Most Loctite and Permatex gasket makers specify a minimum of 1 hour before adding fluids and a full 24 hours before returning to service. Some fast-cure formulations reduce this window, but 24 hours remains the safe default unless the specific product's TDS states otherwise. Cure time increases in cold or low-humidity conditions. What should RTV not be used on? Do not use RTV gasket maker on: head gaskets, exhaust manifold gaskets, or any surface exposed to combustion gases or pressure — these require engineered cut gaskets. Do not use standard (non-sensor-safe) RTV on any joint connected to the engine crankcase if the vehicle has oxygen sensors. Do not use RTV silicone on surfaces that will be immersed in petrol or aromatic fuels — RTV is not fuel-resistant and will swell and fail. Do not use RTV as a replacement for O-rings, lip seals, or precision-fit rubber components. Do not apply RTV over existing cured sealant, silicone residue, or contaminated surfaces — the new bead will not bond and the joint will leak. Where a rigid, load-bearing bond is required, two-part epoxy adhesive is typically the more appropriate choice than RTV silicone. What will RTV silicone not stick to? RTV silicone does not adhere reliably to: polyethylene (PE), polypropylene (PP), PTFE (Teflon), wax, oil-contaminated surfaces, or existing cured silicone. It also has poor adhesion to very smooth, non-porous surfaces unless a primer is used. In an engine context, the most important point is surface preparation — any oil, grease, old sealant, or gasket material residue on the mating faces will prevent a reliable bond and lead to early seal failure. Both faces must be thoroughly cleaned and degreased before applying RTV gasket maker. Use a fast-evaporating industrial degreaser such as acetone or IPA — solvent choice matters for aluminium and painted surfaces. How thick should I apply RTV gasket maker? Apply a continuous bead of approximately 3–4 mm in diameter — roughly the width of a pencil. Thinner than this risks gaps in the seal; thicker than this causes excess material to squeeze out under bolt load and enter the engine or gearbox interior. Excess RTV that squeezes inward can break off as plugs once cured and circulate through the oil system. Apply the bead as a single, unbroken line around the entire sealing face, going around fastener holes (not across them). Assemble immediately after applying — do not leave a bead exposed to atmosphere for more than a few minutes before joining the surfaces, as the outer skin will begin to cure and may not compress and bond correctly. Shop Gasket Sealants at AIMS Industrial AIMS Industrial stocks a full range of RTV silicone gasket makers and anaerobic flange sealants from Loctite, CRC, Sanvo, and Ultraloc — available online with fast Australia-wide delivery. Shop Gasket Sealants & RTV Silicone → For thread sealants, threadlockers, retaining compounds, and other Loctite products, see our Loctite Threadlocker & Industrial Adhesives Guide. For Loctite instant adhesives including Loctite 401, see our Loctite 401 Instant Adhesive Guide. Cross-reference our Metric Bolt Torque Chart when tightening grade 8.8, 10.9 or 12.9 fasteners. People Also Ask — RTV Silicone Gasket Maker Q: What is RTV silicone gasket maker used for? RTV (room temperature vulcanising) silicone gasket maker creates flexible, leak-proof seals between mating engine and mechanical surfaces. Common applications include valve covers, timing covers, differential covers, and intake manifold joints — anywhere a pre-cut gasket isn't available or an original gasket has failed. Q: How long does RTV silicone take to cure before startup? Most RTV products skin over in 15–20 minutes but need 1–4 hours minimum cure before startup, with full cure in 24 hours at room temperature. Rushing this step is a common cause of seal failure. Always check the product datasheet — high-temperature formulations may need longer initial set times. Q: What is the difference between black, red, and grey RTV silicone? Black RTV is general-purpose, rated to approximately 260°C. Red RTV handles higher temperatures (typically 300–345°C) for exhaust manifolds and turbo housings. Grey RTV is used in OEM service applications where a lower-odour, sensor-safe formula is needed. Match the colour/type to the operating temperature and application. Q: How do you apply RTV gasket maker correctly? Clean both surfaces thoroughly with degreaser and allow to dry completely. Apply a continuous, even bead of 3–6 mm diameter around all bolt holes and the perimeter of the joint. Assemble within the open time — typically 10–15 minutes — then torque bolts to specification in a cross-pattern to ensure even seating. Q: Can RTV silicone be used on coolant system joints? Yes, but use a coolant-specific or sensor-safe (non-corrosive) formulation. Standard RTV releases acetic acid during cure, which can corrode aluminium and copper coolant fittings. Sensor-safe formulations use a non-acidic cure mechanism and are safe for use near oxygen sensors and in coolant-facing applications. For workshop solvent cleaning, see the AIMS parts washer range.RTV silicone forms a gasket in place rather than bonding two rigid parts together — if the job is actually bonding, not sealing a mating surface, an instant adhesive is the more appropriate product. See our Loctite 406 Guide for bonding plastics and rubber.
Read moreLinear Bearing Guide: Types, Sizes & How to Choose
Linear bearings sit behind a lot of machinery that most people never think about — the slide on a CNC router, the vertical axis on a pick-and-place machine, the transfer carriage in a packaging line. They do one job: allow controlled, low-friction movement along a fixed path. Get the selection right and they run quietly for years. Get it wrong and you'll be replacing them inside a year under real load. This guide covers what linear bearings are, how they work, the different types available, and how to select the right bearing for the shaft size, load, and environment. It's aimed at maintenance fitters, machine builders, and anyone sourcing replacements or specifying new linear motion components for industrial equipment. See the AIMS Bearing Brand Comparison guide for a full honest breakdown of the Japanese Tier-1 brands (NACHI, NSK, Koyo, NTN) plus specialty brands including Timken and McGill. What Is a Linear Bearing? A linear bearing is a bearing designed to allow movement in a straight line — along an axis — rather than rotational movement. Unlike a radial ball bearing, which supports a rotating shaft, a linear bearing supports and guides a shaft or rail that moves back and forth in a straight path. The standard recirculating ball linear bearing (the LM series used in automation, CNC, and industrial equipment) consists of an outer steel cylinder housing a recirculating track of ball bearings. As the bearing moves along a hardened steel shaft, the balls roll along the shaft surface and recirculate through internal return channels, maintaining continuous contact with minimal friction throughout the stroke. The result is a bearing that can traverse a shaft repeatedly with very low rolling friction — typically a coefficient of friction of 0.001 to 0.004, compared to 0.10 to 0.15 for plain sliding contact. This makes recirculating ball linear bearings suitable for high-speed, precise, and repetitive linear motion applications. How Does a Linear Bearing Work? In a recirculating ball linear bearing, a series of ball bearings sit within internal raceways arranged in rows along the bearing body. As the bearing moves along the shaft, the balls in contact with the shaft roll and are channelled through a return passage inside the bearing housing, bringing them back to re-enter the loaded zone. This recirculation means the bearing can traverse an unlimited stroke — unlike a simple ball cage, which can only travel as far as the balls allow. The recirculating design is what enables the LM bearing series to support high loads and long strokes in machinery. The key to performance is the hardened shaft. Standard linear bearings require a case-hardened shaft of SUJ2 bearing steel (equivalent to AISI 52100) ground to an h6 tolerance and surface-hardened to HRC 60–62. A soft shaft or an incorrectly sized shaft will result in rapid wear and premature failure — the shaft, not the bearing, is often the first component to fail in poorly specified systems. Types of Linear Bearings Three main categories of linear bearing are in common use in industrial and automation applications, each with different performance characteristics. Recirculating Ball Linear Bearings (LM Series) The LM series — also referred to as ball bushings or linear ball bearings — is the dominant type for general industrial and automation use. These are the cylindrical bearings pressed into a housing bore, designed to slide along a round hardened steel shaft. They are available in standard (UU — double-sealed) and open configurations. The LM designation follows a straightforward naming convention. The number indicates the bore diameter in millimetres (matching the shaft diameter). The suffix indicates the sealing and length variant: No suffix: open bearing — no end seals, requires regular lubrication U: single rubber seal on one end UU: double rubber seals — one on each end — the standard for most applications L: long version — extended length for higher load capacity and moment resistance LUU: long version with double seals So an LM12UU is a 12mm bore, double-sealed, standard-length linear bearing. An LM25LUU is a 25mm bore, double-sealed, long version. LM series bearings are precision components — housing bore and shaft diameter tolerances must be within specification for the bearing to perform correctly. A housing bore to H7 tolerance and a shaft to h6 tolerance is the standard pairing for a light interference fit in the housing and a sliding fit on the shaft. Plain and Polymer Linear Bearings Plain linear bearings — also called linear bushings or sleeve bearings — replace the recirculating ball mechanism with a sliding contact surface. The bearing slides directly along the shaft with no rolling elements. Bronze and sintered bronze bearings are self-lubricating — oil is impregnated into the porous metal structure and is released under load. They are robust, tolerant of misalignment, and can operate in environments where contamination would destroy a recirculating ball bearing. Load capacity per unit length is lower than LM series, but they handle shock loads and misalignment better. Polymer plain bearings — of which the igus drylin system is the most well-known in AU — are made from engineered polymers with embedded solid lubricants. They require no grease or oil, are corrosion-resistant, and tolerate dust, moisture, and light contamination. They are widely used in food processing, pharmaceutical manufacturing, and outdoor machinery where contamination of lubricants is a concern and where metal-on-metal contact is undesirable. The trade-off with polymer bearings is load capacity (lower than recirculating ball) and dimensional sensitivity (coefficient of thermal expansion is higher than steel — clearances must account for temperature variation). They are also less suitable for high-speed applications where heat generation at the sliding contact becomes a limiting factor. Linear Guide Rails (Profiled Rail Systems) Linear guide rails — THK, Hiwin, Bosch Rexroth, and similar — are a fundamentally different architecture. Instead of a cylindrical bearing running on a round shaft, a profiled steel rail carries a precision-machined carriage block. Multiple rows of recirculating balls or rollers sit between the carriage and the rail, providing high load capacity in all directions (radial, reverse radial, and lateral). Linear guide rails offer significantly higher load ratings than round shaft LM bearings, better moment capacity, and higher stiffness. They are the standard choice for machine tools, precision machining centres, and high-load automation where LM bearings would be undersized. The trade-off is cost and installation precision — rail surfaces must be ground flat to within fractions of a millimetre, and the carriage preload must be correctly specified for the application. They are not a drop-in substitute for round shaft bearings; they require precision mounting surfaces and correct rail alignment. LM Series Sizing Guide The table below covers the standard LM series range with principal dimensions. All dimensions are in millimetres. Load ratings are approximate dynamic load ratings (C) for standard-length UU variants — actual ratings vary by manufacturer. Designation Bore (mm) OD (mm) Length (mm) Long (LUU) Length (mm) Approx. C (kN) LM6UU 6 12 19 35 0.5 LM8UU 8 15 24 45 1.4 LM10UU 10 19 29 55 2.2 LM12UU 12 21 30 57 3.2 LM16UU 16 28 37 70 5.6 LM20UU 20 32 42 80 9.4 LM25UU 25 40 59 112 16.2 LM30UU 30 45 64 123 22.0 LM35UU 35 52 70 134 32.0 LM40UU 40 60 80 154 42.0 LM50UU 50 75 100 192 68.0 LM60UU 60 90 125 240 100.0 LM80UU 80 120 165 320 196.0 The most common sizes in Australian industrial maintenance and automation are LM8UU (used extensively in 3D printers, small CNC machines, and light automation), LM12UU through LM20UU (general automation, transfer mechanisms), and LM25UU through LM40UU (heavier machinery, industrial slides, and transfer carriages). Load Ratings Explained Linear bearing datasheets specify two load ratings: dynamic load rating (C) and static load rating (C0). Understanding the difference matters when specifying or replacing a bearing under real load. Dynamic load rating (C) is the load under which a bearing will achieve a rated travel life — typically expressed in kilometres of travel. The ISO standard for linear bearings uses 50km as the reference life (L10 = 50km at 90% reliability). Dynamic load rating is used for applications with continuous or frequent reciprocating movement — conveyor slides, transfer mechanisms, robotic axes. Static load rating (C0) is the maximum load the bearing can support without permanent deformation of the balls or raceway. Static load rating applies to applications where the bearing is stationary under load, or where shock loading occurs. For applications with infrequent movement and high static loads, C0 is the relevant figure — not C. The basic travel life calculation follows the ISO formula: L = (C/P)³ × 50, where L is life in km, C is dynamic load rating in kN, and P is the applied load in kN. Halving the applied load increases travel life by approximately eight times — load management has a disproportionate effect on bearing life. For critical applications, a safety factor of 2–3 applied to the calculated load is standard practice in industrial machine design. This accounts for shock loads, vibration, misalignment, and acceleration forces that are difficult to quantify precisely in real-world machinery. What Rail Material Is Best for Linear Bearings? For standard recirculating ball linear bearings (LM series), the shaft must be a hardened steel rod — not mild steel, not aluminium, not stainless. The minimum surface hardness requirement is HRC 58. The standard shaft material is SUJ2 bearing steel (JIS standard), equivalent to AISI 52100 / EN 31. It is case-hardened to HRC 60–62 and ground to h6 tolerance. The practical answer is: buy matched shafts from the same supplier as the bearings. Using a mild steel rod as an improvised shaft will result in shaft wear, not bearing wear — the shaft surface will be scored within a short period of use. This is the most common installation error encountered in the field. Chrome-plated shafts are also commonly available. Chrome plating adds corrosion resistance to the hardened steel core — useful for applications where condensation or light moisture is present. The chrome layer is typically 10–25 microns and does not significantly change shaft dimensions for standard bearing fit. Chrome-plated shafts are appropriate for food processing, marine, and washdown environments. Stainless steel shafts are available for corrosive environments but require careful selection — standard austenitic stainless (304, 316) is too soft and will score. Martensitic stainless or specially hardened stainless grades are required for LM series bearings. Confirm hardness ≥ HRC 58 before specifying stainless shafts with standard LM bearings. For polymer plain bearings (igus drylin), the shaft material options are broader — anodised aluminium shafts, hard-chrome steel, and stainless all work because the polymer sliding contact is self-lubricating and less demanding on shaft hardness than recirculating balls. This is one of the practical advantages of polymer systems in environments where sourcing and maintaining hardened steel shafts is difficult. Sealed vs Open Linear Bearings The sealing suffix on LM bearings indicates the type and number of end seals: Open bearings (no suffix) have no end seals. Grease can be applied directly into the ball track from the ends. They are used in clean, controlled environments where regular maintenance is possible — precision machine tools, enclosed enclosures, applications where the bearing can be accessed frequently for relubrication. Open bearings are also used where compact installation length is critical. Single-seal (U) bearings have one rubber lip seal on one end. Partial protection — useful where contamination approaches from one direction only. Less common in standard practice. Double-seal (UU) bearings have rubber lip seals on both ends. This is the standard specification for general industrial use. The seals retain grease inside the bearing and exclude dust, swarf, and light contamination from entering the ball track. For most maintenance replacement applications, UU is the correct choice — it requires less frequent relubrication and is more tolerant of imperfect environments. The UU suffix seals are contact lip seals — they provide good retention but add a small amount of friction compared to an open bearing. In high-speed applications (linear speed >2 m/s consistently), this friction can become relevant. For standard industrial speeds (typically <0.5 m/s in most maintenance applications), it is not a practical concern. Can Linear Bearings Be Used Vertically? Yes. Linear bearings can be used in any orientation — horizontal, vertical, or at any angle. The bearing mechanism functions identically regardless of orientation. The considerations specific to vertical applications are: Load direction: In a vertical application, the weight of the moving element (carriage, toolhead, gripper assembly) acts as a constant downward load throughout the stroke. The bearing must be rated for this load — check that the applied load is within the dynamic load rating under continuous operation. For heavy vertical loads with long strokes, the long LUU version increases load rating and improves moment resistance. Grease retention: Gravity draws grease downward in a vertical orientation. In sealed (UU) bearings, this is largely managed by the end seals. For open bearings used vertically, more frequent relubrication of the upper end of the bearing may be required, as grease migrates away from the upper contact zone over time. This is a practical issue in long-service vertical applications — not a barrier to use, but a maintenance consideration. Self-weight of the carriage under power loss: In vertical systems where the carriage is power-driven, consider what happens if power is lost and the drive disengages. The carriage will travel under gravity at whatever speed the linear bearing permits. If this is a hazard, a brake or counterbalance must be part of the system design — the linear bearing itself does not provide resistance to free travel. This is a system design issue, not a bearing limitation. Polymer vs Recirculating Ball: Which Should You Choose? The choice between polymer plain bearings and recirculating ball bearings depends on the operating environment, load, speed, and maintenance context. There is no universal answer — both types are in widespread use in Australian industry for valid reasons. Choose recirculating ball (LM series) when: Precision of positioning matters — LM bearings have tighter running clearance and better repeatability High speed is required — rolling contact handles higher linear speeds with less heat generation Load capacity is critical — LM series outperforms polymer by a significant margin per unit size The environment is clean and controlled — lubricant contamination is not a concern The application is standard automation, CNC, 3D printing, or transfer machinery Choose polymer plain bearings when: Maintenance access is difficult or infrequent — polymer runs dry indefinitely, no relubrication required The environment is wet, dusty, or contaminated with food products, cleaning agents, or fine particles that would contaminate lubricant Corrosion resistance is required — polymer and anodised aluminium shafts can be used where steel would corrode Noise is a constraint — polymer bearings are quieter than recirculating ball bearings in service The application is outdoor, agricultural, or food processing The forum consensus among engineers on r/3Dprinting and r/robotics is that recirculating ball bearings (LM series) win on precision and speed, while polymer bearings win on reliability in contaminated or maintenance-inaccessible environments. Both assessments are correct for their respective contexts — the selection decision should be driven by the operating environment and maintenance reality, not by cost alone. Moment Loading and Minimum Bearing Span A linear bearing loaded purely in the radial direction (load perpendicular to shaft, no offset) is in its optimal loading condition. Moment loading — where the applied load creates a turning force about the bearing — reduces the effective load capacity significantly and must be accounted for in design. Moment loads arise when: the load point is offset from the bearing centreline, a single bearing supports a cantilevered load, or acceleration forces act on a load with a centre of mass offset from the shaft axis. In engineering terms, moment load (M) = applied force (F) × offset distance (L). The standard practice for managing moment loads is to use two bearings per shaft, spaced as far apart as the application allows. Increasing the bearing span by a factor of 2 reduces the effective moment on each bearing by a factor of 2. For heavily cantilevered loads, LUU (long) bearings are preferred over standard-length bearings — the longer bearing body distributes moment force over more ball contact points. For critical applications with significant moment loading, a profiled linear guide rail system (THK/Hiwin style) is more appropriate than LM round shaft bearings — the four-way load capacity of a profiled rail carriage handles moment loading far more effectively than a round shaft bearing can. Installation and Alignment Correct installation is the single biggest factor in linear bearing service life after correct sizing. The most common causes of premature failure are not bearing defects — they are installation errors. Housing bore tolerance: The housing bore must be machined to H7 tolerance for a standard LM bearing. A bore that is too tight will crush the outer race and reduce internal clearance, causing the bearing to run rough or seize. A bore that is too loose will allow the bearing to spin in the housing under load, causing housing wear and eventual loss of positional accuracy. Do not attempt to compensate for an oversized bore with adhesive alone — re-machine the housing or use an interference-fit sleeve. Press fitting: Always press on the outer race — never the inner race or balls. Pressing on the inner race forces the load through the balls, which can indent the raceways and cause premature failure. Use a mandrel or press tool that contacts only the outer ring end face. A soft mallet against a properly fitting mandrel is acceptable for light-interference installations. Shaft alignment: Two parallel shafts (as in a twin-shaft gantry or slide) must be parallel within the manufacturer's specified tolerance — typically 0.05 to 0.1mm over the full shaft length. Misalignment creates a pre-load on the bearings throughout the stroke, drastically reducing service life and increasing operating force. If the carriage feels stiff or jerky when moved by hand with no external load applied, misalignment or housing bore error is the cause. For applications requiring precision shimming of shaft supports to achieve correct alignment, refer to the AIMS industrial shim guide — shim stock selection and material considerations apply directly to linear motion system alignment work. Shaft support spacing: Support the shaft at intervals appropriate to its diameter and expected load. Unsupported shaft spans that are too long will allow the shaft to deflect under load, creating a curved travel path that overloads the bearing in the deflection zone. As a general guideline, the support span should not exceed 40–60 times the shaft diameter for standard industrial loads — shorter spans for heavier loads or higher speed applications. Lubrication and Maintenance Recirculating ball linear bearings require lubrication to protect the ball-to-raceway contact surfaces. Without adequate lubrication, the Hertzian contact stress at ball-to-raceway interfaces causes surface fatigue and early failure — typically spalling of the raceway surface. Grease: NLGI 2 lithium-based grease is the standard specification for sealed LM bearings in general industrial applications. Apply a small amount of grease through the nipple fitting (if present) or by removing the end seal and applying directly. Grease quantity matters — over-packing creates churning resistance and heat; under-packing starves the contact. As a general guide, fill approximately one-third of the internal free space. Oil: Light machine oil (ISO VG 32 or VG 46) is used in applications where grease would be displaced by high-speed recirculation, or where the bearing is part of an oil recirculation system. Oil-lubricated open bearings require more frequent replenishment than grease-lubricated sealed bearings. Relubrication intervals: For general industrial applications with sealed UU bearings under moderate load and speed (linear speed <0.5 m/s, load <30% of rated capacity), a relubrication interval of 6–12 months is a reasonable starting point. Increase frequency for higher speeds, higher loads, elevated temperature, or contaminated environments. The symptom of inadequate lubrication is increased operating noise — a clicking or grinding sound that develops gradually as the bearing surface deteriorates. For open bearings or applications in contaminated environments, a penetrating lubricant used as a maintenance flush (to clear contamination before regreasing) can extend bearing life between full replacements. See the AIMS penetrating oil guide for product selection by application context. Polymer plain bearings: Require no lubrication — self-lubricating material releases lubricant under load from the bearing matrix. Do not apply grease or oil to polymer bearings — it attracts dirt, which then acts as an abrasive and accelerates wear. Keep polymer bearings dry and clean. Common Failure Modes and How to Identify Them Understanding how a linear bearing fails helps in diagnosing cause and preventing recurrence in the replacement bearing. Spalling (raceway fatigue): Surface flaking of the raceway or ball surface. Appears as a rough, irregular texture in the ball track zone. Cause: fatigue under load — normal end-of-life mode if the bearing has reached its rated travel life. Premature spalling indicates overloading, contamination, or inadequate lubrication. Scoring and scratching: Linear grooves in the raceway or shaft surface running parallel to the shaft axis. Cause: contamination — hard particles (swarf, grit, debris) trapped between balls and raceway. Prevention: sealed bearings (UU), shaft wipers, and cleaner operating environment. Replacement of the shaft may also be required if the scoring is significant. Pitting and corrosion: Rust pitting on balls or raceway. Cause: moisture ingress into the bearing — condensation in a closed environment, washdown without sealed bearings, or inadequate sealing. Prevention: chrome-plated shafts, sealed UU bearings, stainless variants for extreme environments, and correct storage (bearings stored in factory packaging with desiccant until installation). False brinelling: Evenly spaced indentations in the raceway matching ball spacing. Cause: vibration while stationary — the bearing oscillates slightly under vibration without full rolling motion, causing Hertzian contact damage at rest positions. Common in machinery shipped long distances or stored adjacent to vibrating equipment. Prevention: store and transport with shaft in place or with a dummy shaft through the bearing; isolate from vibration during storage. Excessive noise: Clicking, rattling, or grinding during travel. Cause: contamination, inadequate lubrication, overloading, or worn raceways. If a bearing that previously ran quietly begins to produce noise under unchanged operating conditions, check lubrication first — then inspect for contamination. If noise persists after relubrication, replacement is the correct action. Sourcing Linear Bearings in Australia The LM series is globally standardised — an LM12UU from any reputable manufacturer (THK, NSK, Hiwin, IKO, PMI) will have the same external dimensions and is interchangeable with any housing machined to H7 bore tolerance. This standardisation means replacement sourcing is straightforward: you need the designation, not the brand. For rotating bearings in the drive systems that pair with linear motion assemblies — motor end-shield bearings, gearbox bearings, idler shafts — the AIMS Bearing Cross Reference Guide decodes SKF, NSK, NTN, FAG, Koyo, NACHI and other brand designations for those components. Quality variation exists between manufacturers. Precision grade (P5 or P4) bearings from major Japanese and Taiwanese manufacturers hold tighter tolerances than standard-grade economy bearings. For precision CNC applications or medical/food processing machinery, specify the precision grade. For general industrial slides, transfer carriages, and maintenance replacements, standard grade is adequate and represents significantly better value. For LM8UU through LM40UU, same-day or next-day availability from industrial bearing suppliers in Australia is typical for standard UU variants. LUU (long) versions and larger sizes (LM50UU and above) may require 2–5 working days. Linear guide rail systems (THK, Hiwin) generally require longer lead times if not held in local stock — confirm availability before committing to a design that depends on them. Frequently Asked Questions How does a linear bearing work? A linear bearing allows controlled, low-friction movement along a straight path. In the most common type — the recirculating ball linear bearing (LM series) — a series of steel balls sits in internal raceways within the bearing body. As the bearing moves along a hardened steel shaft, the balls roll along the shaft surface and recirculate through internal return channels, maintaining continuous contact. This rolling contact produces very low friction (typically 0.001–0.004 coefficient of friction) compared to plain sliding contact, making it suitable for high-speed, precise, and repetitive linear motion applications. What are the different types of linear bearings? The three main categories are: recirculating ball linear bearings (LM series — cylindrical bearings running on round hardened steel shafts, the most common type in automation and industrial equipment), polymer or plain linear bearings (self-lubricating bushings for contaminated or maintenance-inaccessible environments), and linear guide rail systems (profiled steel rails with recirculating ball or roller carriages, used for high-load and high-precision machine tool applications). Each type suits different load, speed, precision, and environmental requirements. Can linear bearings be used vertically? Yes. Linear bearings operate correctly in any orientation — horizontal, vertical, or at an angle. In vertical applications, the bearing must be rated to support the weight of the moving element as a continuous load. Grease retention in sealed bearings (UU) is generally adequate for vertical use, though open bearings in vertical orientation may require more frequent relubrication of the upper end as gravity draws grease downward over time. The bearing itself does not resist free travel under gravity — if power loss would allow an unsupported carriage to fall, a brake or counterbalance must be part of the system design. What does LM8UU mean? LM8UU is the designation for a specific linear bearing. LM stands for Linear Motion. The number (8) is the bore diameter in millimetres — this must match the shaft diameter. UU indicates double rubber end seals on both ends of the bearing, which retain grease and exclude contamination. The standard LM8UU has a bore of 8mm, outer diameter of 15mm, and length of 24mm. An LM8LUU is the long version of the same bearing, with a length of 45mm for higher load capacity. What is the difference between LM and LME bearings? LME bearings are a metric variant of the LM series common in European machinery. They have the same bore diameter as the equivalent LM bearing but different outer dimensions — the outer diameter and length follow European metric standards rather than the JIS (Japanese Industrial Standard) used for the LM series. LM and LME bearings are not directly interchangeable if the housing bore has been machined to a specific series. When replacing a bearing, confirm whether the housing was designed for LM or LME dimensions before ordering. LM series is the more common format in Australian industrial equipment and automation. How do I choose the right size linear bearing? Start with the shaft diameter — the bore of the bearing must match the shaft. Then check the dynamic load rating (C) of the candidate bearing against your application load with a suitable safety factor (2–3× for industrial applications). If the standard-length bearing is marginal on load capacity, move to the long (LUU) version of the same bore size. For applications with significant moment loading (offset loads, cantilevered carriages), use two bearings per shaft spaced as far apart as practical. If your calculated load exceeds what the LM series can handle at the required bore size, consider a linear guide rail system instead. What is the difference between polymer and recirculating ball linear bearings? Recirculating ball bearings (LM series) use rolling ball contact for very low friction, high load capacity, and high precision. They require lubrication and are sensitive to contamination. Polymer bearings (igus drylin and similar) use a self-lubricating polymer sliding contact — they require no grease, tolerate contamination and moisture, and are corrosion-resistant, but have lower load capacity and are less precise. Choose recirculating ball for standard automation, CNC, and precision applications in clean environments. Choose polymer for food processing, outdoor, washdown, or maintenance-inaccessible applications where contamination of lubricant is a real concern. How long do linear bearings last? Service life depends on load, speed, lubrication, and contamination. The ISO standard reference life is 50km of travel at 90% reliability under rated dynamic load (C). Reducing the applied load significantly extends life — halving the load increases travel life by approximately eight times (life scales with the cube of the load ratio). In a well-maintained, correctly loaded industrial application, LM series bearings routinely achieve hundreds of kilometres of travel. Common causes of early failure are contamination (swarf, grit), inadequate lubrication, overloading, and misalignment — none of which are inherent bearing weaknesses. Do linear bearings need lubrication? Recirculating ball linear bearings (LM series) do require lubrication. Without lubricant, the ball-to-raceway contact stress causes surface fatigue and early failure. NLGI 2 lithium grease is standard for sealed bearings in general industrial use. Sealed UU bearings come pre-greased and require periodic relubrication (typically every 6–12 months under moderate conditions). Open bearings require more frequent attention. Polymer plain bearings (igus drylin) are self-lubricating and do not require — and should not receive — added grease or oil. What causes linear bearings to fail early? The most common causes of premature linear bearing failure are: contamination (swarf, grit, or abrasive particles entering the ball track — prevented by sealed UU bearings and clean installation), inadequate lubrication (dry contact causes rapid raceway fatigue — maintain correct relubrication intervals), incorrect shaft hardness (using a mild steel rod instead of hardened SUJ2 bearing shaft — the shaft wears rapidly and destroys the bearing), misalignment (parallel shafts out of alignment create a pre-load throughout the stroke, drastically reducing life), and overloading (exceeding the dynamic load rating — always apply a 2–3× safety factor). What is a linear guide rail and how does it differ from a linear bearing? A linear guide rail is a profiled steel rail paired with a precision carriage block — as used in machine tools, CNC machining centres, and precision automation. Multiple rows of recirculating balls or rollers between the carriage and rail provide high load capacity in all directions, including moments. A standard round-shaft LM linear bearing runs on a cylindrical shaft and handles radial loads and limited moments. Linear guide rails offer significantly higher stiffness, load capacity, and moment resistance than round shaft bearings, but require precision ground mounting surfaces and carry a higher cost. They are the correct choice for heavy machine tool applications; LM round shaft bearings suit lighter automation and general industrial use. What is the correct housing bore tolerance for LM linear bearings? The standard housing bore tolerance for LM series linear bearings is H7 (for example, an LM12UU with 21mm OD requires a housing bore of 21mm H7). H7 provides a light interference fit between the bearing outer race and the housing, preventing the bearing from rotating in the housing under load. A bore machined too tight will crush the outer race and cause the bearing to run rough or seize. A bore too loose allows the bearing to spin in the housing, wearing both components. Do not attempt to compensate for an oversized bore by applying adhesive alone — the housing must be correctly sized for the bearing to perform as specified. For GD&T symbols and their meanings under Australian and international standards, see our GD&T Symbols Guide. AIMS Industrial stocks loc-line — see the full range for trade and industrial use.How far apart should shaft supports be spaced on a linear bearing system? Support the shaft at intervals appropriate to its diameter and the expected load — as a general guideline for standard industrial loads, the support span should not exceed 40 to 60 times the shaft diameter, with shorter spans required for heavier loads or higher-speed applications. Unsupported shaft spans that are too long allow the shaft to deflect under load, creating a curved travel path that overloads the bearing in the deflection zone rather than distributing load evenly along the shaft. If a linear bearing carriage feels stiff or jerky at certain points along its travel but smooth elsewhere, check the shaft support spacing before suspecting the bearing itself. What is moment loading on a linear bearing and how do I avoid it reducing capacity? Moment loading occurs when the applied load creates a turning force about the bearing — for example when the load point is offset from the bearing centreline, a single bearing carries a cantilevered load, or acceleration acts on an off-centre mass. Moment load (M) equals applied force (F) multiplied by offset distance (L). The standard fix is to use two bearings per shaft spaced as far apart as the application allows — doubling the bearing span halves the effective moment on each bearing. For heavily cantilevered loads, long (LUU) bearings or a profiled linear guide rail system are more appropriate than standard-length round-shaft bearings. Are THK, NSK, Hiwin, IKO and PMI linear bearings interchangeable? Yes, for the standard LM series — it is globally standardised, so an LM12UU from any of these manufacturers has the same external dimensions and fits a housing machined to H7 bore tolerance regardless of brand. Replacement sourcing only needs the size designation, not the original brand. Quality does vary between manufacturers though: precision-grade (P5 or P4) bearings from major Japanese and Taiwanese makers hold tighter tolerances than standard-grade economy bearings, which matters for precision CNC or medical/food processing machinery but is unnecessary for general industrial slides and maintenance replacements. What is the difference between standard-grade and precision-grade (P5/P4) linear bearings? Standard-grade bearings are adequate for general industrial slides, transfer carriages and routine maintenance replacements, and represent significantly better value where ultra-tight tolerances are not required. Precision grade (P5 or P4) bearings hold tighter dimensional and running tolerances and are specified for precision CNC applications or medical and food processing machinery where positioning accuracy and repeatability matter more than cost. Availability also differs: standard LM8UU through LM40UU are typically stocked for same-day or next-day supply, while precision-grade and larger sizes may need 2-5 working days lead time.
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Loctite 243 Guide: Medium-Strength Threadlocker Use
Loctite 243 is the most widely used threadlocker in Australian industrial and maintenance applications. Walk into any workshop, service bay, or trade.
Read moreIndustrial Rust Remover Guide: Types, Methods & Best Practices
Rust is iron oxide — what forms when iron or steel reacts with oxygen and moisture over time. Once it takes hold, it weakens the metal, seizes.
Read morePenetrating Oil & Spray Lubricants: What to Use and When
What Is Penetrating Oil? Penetrating oil is a low-viscosity solvent-based lubricant designed to wick into the tight gaps between corroded, seized or rusted threaded fasteners and joints. The thin carrier solvent flashes off after creeping into the joint, leaving a lubricant film that breaks the friction bond between rust and metal. It's the first tool to reach for on a stuck bolt, seized fitting, frozen hinge or rusted pin — before resorting to heat, impact or extraction. Is penetrating oil the same as WD-40? Not exactly. WD-40 (the original blue-can product) is a multi-purpose water displacement spray with mild penetrating action. Dedicated penetrating oils — like CRC 5-56, Aerokroil, Plus Gas and WD-40 Specialist Penetrant — have stronger, more aggressive solvent formulations specifically engineered to free seized fasteners. For light corrosion WD-40 may do the job; for badly seized fasteners use a dedicated penetrant. For a full rundown on what WD-40 is actually for (and where CRC 5-56 and dedicated penetrants take over), see our WD-40 FAQ. Need to pick the right Loctite product? Our Loctite Application Guide maps every grade to its job. For grease gun selection (lever, pneumatic, battery), see our grease guns range. For tin snips and aviation shears (straight, left-cut, right-cut), see our snips and shears range. Penetrating Oil & Spray Lubricants: What to Use and When May 11, 2026 AIMS Industrial Penetrating Oil & Spray Lubricants: What to Use and When May 11, 2026 AIMS Industrial Penetrating Oil & Spray Lubricants: What to Use and When Apr 28, 2026 AIMS Industrial Pick up the wrong can and you will waste time, money, and sometimes damage what you are trying to fix. In Australian workshops, the most common error is treating WD-40 or CRC 5-56 as an all-purpose lubricant — applying it to chains, bearings, and hinges that need lasting protection, not a light penetrant that evaporates in an hour. The second most common error is reaching for silicone spray when you need something that will actually penetrate rust. This guide covers every major category of spray lubricant and penetrating oil available in Australia: what each product is formulated to do, where it performs well, where it fails, and which products AIMS Industrial stocks for trade and industrial applications. The WD-40 vs lubricant debate gets a definitive answer. So does every related question about CRC 5-56, INOX MX3, silicone spray, dry PTFE, and the rest of the field. Products covered: WD-40 Original, WD-40 Specialist range, CRC 5-56, INOX MX3, INOX Lanox MX7, CorrosionX, Rocol, Molytec, Dy-Mark, Helmar, and 3-in-1 Oil. WD-40 vs CRC 5-56 vs Aerokroil — Penetrating Oil Quick Reference Penetrating oils break the bond between rusted threads, seized fasteners + corroded joints. Despite popular use, WD-40 is a water-displacing oil — not a true penetrating oil. The comparison below shows what each product is actually designed for. Product Best Use Penetration Rating WD-40 (Original) Water displacement, light lube, displacing moisture from electrics Low — not a true penetrant CRC 5-56 Multi-purpose — light penetrating, lubricating, water-displacing Medium CRC Knock'er Loose Heavy penetrant — seized fasteners + rust High WD-40 Specialist Penetrant Capillary action — rusted fasteners High Aerokroil (Kano Labs) Premium — extreme penetration via molecular size Very High — industry benchmark PB Blaster Workshop seized bolts + automotive High Loctite Freeze + Release Thermal shock + penetrant combined Very High — best for stubborn rust ATF + Acetone (50/50 DIY) Workshop home brew — surprisingly effective Very High — independent tests confirm Critical: WD-40 is the brand name people reach for, but it's NOT the strongest penetrant. For seized fasteners use a dedicated penetrant + give it 15-30 minutes (longer if rust is heavy). Apply, tap with a hammer to set up vibration, then attempt removal. Heat (oxy torch) is the most effective rust-breaker but creates fire risk. AIMS stocks inspection, WD-40, CRC, Loctite, lubrication + cutting lubricants. What Is a Penetrating Oil? A penetrating oil is a low-viscosity fluid formulated to creep into the microscopic gap between corroded metal surfaces — seized fasteners, rusted threads, stuck bolts, corroded electrical contacts — and chemically break the bond created by rust, oxidation, and mineral scale. It achieves this through a combination of solvents, surfactants, and light carrier oils that wick along metal surfaces via capillary action. The key distinction: penetrating oil is not a lubricant in the practical sense. A lubricant creates a lasting film between moving surfaces to reduce friction over time. A penetrating oil breaks corroded joints apart. Most penetrating oils contain very light carrier oils that evaporate within hours — they provide short-term lubrication as a side effect, but no lasting protection. Using them as a substitute for a proper lubricant is one of the most common and costly maintenance errors in industrial environments. How penetrating oils work Solvent component: Dissolves rust, mineral deposits, and corrosion products that bind metal surfaces together. Petroleum-based solvents are most common; some formulations use synthetic or bio-based solvents. Surfactant component: Reduces surface tension, allowing the fluid to wick into micro-gaps by capillary action. This is the property that makes a penetrating oil different from simply applying engine oil to a rusted bolt. Carrier oil: Suspends the solvents and surfactants, provides temporary lubrication during the break-free process, and helps flush corrosion debris. In INOX MX3 and CorrosionX, the carrier oil is formulated to remain on the surface and provide ongoing corrosion inhibition. The quality difference between penetrating oils comes from the surfactant package and carrier oil volatility. A well-formulated surfactant gets fluid into the joint faster and deeper. A less volatile carrier oil provides better post-application corrosion protection — which is why INOX MX3 outperforms WD-40 for long-term protection despite functioning similarly as an initial penetrant. WD-40: Penetrating Oil, Lubricant, or Solvent? This is the most argued question in every trade workshop and internet forum on the subject. The r/YouShouldKnow thread "WD-40 is a solvent, not a lubricant" generated over 390 comments. Here is the straight answer. WD-40 is primarily a water-displacement fluid and light penetrating oil. The name stands for "Water Displacement, 40th formula" — it was developed in 1953 by Norm Larsen at the Rocket Chemical Company for corrosion protection on Atlas missile components. It was never designed to be a long-term lubricant. What WD-40 contains Petroleum-based mineral spirits (solvent — primary constituent) Light mineral oil (temporary lubricant, approximately 25% of formulation) Liquefied petroleum gas propellant (aerosol form) Proprietary surfactants and corrosion inhibitors WD-40's own website acknowledges that the product provides lubrication — they address the "WD-40 is not a lubricant" myth in their FAQs. It does lubricate. The issue is that the light mineral oil evaporates relatively quickly, so WD-40 Original is not suitable as a long-term lubricant. As a penetrating oil, it works adequately for light to moderate corrosion; for heavily seized fasteners, dedicated penetrating oils outperform it. Where WD-40 works well Displacing moisture from electrical contacts and connections Freeing mildly stuck or lightly rusted hinges, latches, and pivots Short-term surface rust prevention on tools and exposed metal Removing sticker and adhesive residue from metal and glass Loosening mildly corroded nuts and bolts before the main penetrant soak Where WD-40 falls short Heavily corroded or seized fasteners: Modest surfactant formulation compared to dedicated penetrants. For badly rusted joints, use CRC 5-56, INOX MX3, or a purpose-built penetrant. Long-term lubrication: WD-40 evaporates. Using it on chains, bearings, or hinges means constant reapplication and poor protection in between. Rubber and plastic components: Petroleum solvent content can degrade certain rubber compounds and craze some plastics. Check compatibility before use. Food-processing environments: WD-40 Original is not food-safe. Bicycle chains: WD-40 strips existing lubricant without adequately replacing it. The WD-40 Specialist range WD-40 has addressed the limitations of their original formula with the Specialist range — purpose-built products for specific applications. The range includes: Specialist Penetrant (faster-acting, comparable to CRC 5-56), Specialist Silicone, Specialist Dry PTFE Lubricant, Specialist White Lithium Grease, and Specialist Chain Lubricant. If you have been using WD-40 Original for everything, switching to the appropriate Specialist product is a material improvement. CRC 5-56 vs WD-40: The Australian Workshop Standard In Australian trade workshops — manufacturing, fleet maintenance, electrical, mining support, construction — CRC 5-56 has largely displaced WD-40 Original as the go-to penetrating fluid. Both are petroleum-based water-displacement penetrants, but there are meaningful differences. Property WD-40 Original CRC 5-56 Penetrant aggressiveness Moderate Moderate to good Corrosion inhibition Light Better — leaves a protective film Electrical use Good Good — marketed to electricians specifically Trade availability (AU) Excellent — everywhere Excellent — electrical and industrial wholesalers Food safety No No For the core use case — water displacement and light penetration on mildly corroded components — CRC 5-56 and WD-40 Original perform similarly. CRC has a slight edge in corrosion inhibition because its carrier oil leaves a better protective residue. Neither is the right choice for heavy corrosion or long-term lubrication. Types of Spray Lubricants Not all spray lubricants are penetrating oils. There are six distinct product categories, each engineered for a different job. Using the wrong category is the root cause of most maintenance spray errors. 1. Penetrating oils Low-viscosity, high-surfactant formulations designed to wick into corrosion and break seized joints. Light carrier oil provides temporary lubrication only. Not designed for long-term lubrication. Examples (AIMS): CRC 5-56, INOX MX3, CorrosionX, Dy-Mark Penetrating Oil Use for: Seized fasteners, rusted pivots, moisture displacement Do not use for: Long-term lubrication, chains, bearings, rubber seals 2. Silicone spray lubricants Silicone polymer in a carrier solvent. Solvent evaporates, leaving a slippery, clear silicone film. No petroleum — safe on rubber and most plastics. Does not attract dust. Suitable for non-load-bearing applications where a clean, long-lasting film is needed. Examples (AIMS): CRC Silicone Lubricant, Helmar Silicone Spray Use for: Rubber seals, window tracks, door runners, plastic sliding surfaces, conveyor and treadmill belts Do not use for: Surfaces to be painted (silicone prevents adhesion), electrical contacts, load-bearing metal-on-metal, woodworking 3. Dry lubricant sprays (PTFE/Teflon) PTFE particles in a carrier solvent. Solvent evaporates completely, leaving a dry, invisible PTFE film with no sticky residue — will not attract dust or grit. PTFE is the same material used in non-stick cookware. Examples (AIMS): Rocol Dry PTFE Lubricant, CRC Dry Film PTFE Use for: Cables, cable housings, locks, padlocks, bicycle chains (dry conditions), jig table slides Do not use for: High-load applications (insufficient film strength), wet or muddy environments 4. White lithium grease sprays Aerosol-delivered white lithium grease. Heavier and longer-lasting than penetrant-type sprays. Suitable for metal-on-metal sliding contact where spray application is more practical than direct grease. For a full overview of grease types, see the Grease Types & Selection Guide. Use for: Gate hinges, metal drawer runners, exposed sliding joints, trailer couplings Do not use for: Precision bearings, chains, rubber or plastic surfaces 5. Chain lubricants Formulated to penetrate chain link interfaces and remain on the chain under centrifugal load. Available as wet chain lube (oil-based, for heavy industrial chains and wet conditions) or dry chain lube (wax/PTFE-based, for bicycles and dusty conditions). For detailed guidance see the Industrial Roller Chain Guide. Examples (AIMS): Rocol Chain Lubricant, CRC Chain Lube Do not use WD-40 as a chain lubricant — it strips existing lubricant and leaves no lasting film. 6. Corrosion inhibitor sprays Designed primarily for long-term corrosion protection rather than immediate penetration. Leave a durable, water-resistant film on metal surfaces — most effective in marine, agricultural, and outdoor industrial environments. Examples (AIMS): INOX MX3, INOX Lanox MX7 (food-grade), CorrosionX Use for: Marine fittings, outdoor electrical connections, agricultural machinery, exposed fasteners in coastal environments These are for protecting clean or already-treated metal, not for treating active rust that's already present — if rust needs treating first, see AIMS's Rust Converter Guide for how to deal with it in place before applying ongoing protection. INOX, Lanox and Other Australian Penetrant Brands Of the major brands available in Australian workshops, the strongest performer for coastal and agricultural conditions is also one of the least well-known outside the trade. INOX MX3 INOX is made in Brisbane. Developed for Australian conditions, it has become the standard penetrant and corrosion inhibitor in Australian marine, agricultural, and heavy industrial applications. The MX3 product combines penetrating oil, lubricant, and corrosion inhibitor in one formulation. Key advantages over WD-40 and CRC 5-56: the carrier oil is less volatile (lasting protective film after use), corrosion inhibition is significantly better in salt spray testing, and it is generally safe on rubber and most plastics (check SDS for specific polymer compatibility). The trade-off is slightly slower initial penetration — for badly seized fasteners, some tradespeople apply CRC 5-56 first to initiate penetration, then follow with INOX MX3 for protection. Available at AIMS Industrial. INOX Lanox MX7 The food-grade version of INOX MX3. H1 lubricant registered — approved for incidental food contact. Meets FDA, USDA, and Australian food contact requirements. Does not contain petroleum distillates. Required in any HACCP-accredited food processing, beverage, or packaging facility where maintenance spray may contact food or food-contact surfaces. Do not use WD-40, CRC 5-56, or standard INOX MX3 in these environments. Available at AIMS Industrial. CorrosionX Originally developed for the US aviation industry, CorrosionX offers exceptional penetration and corrosion inhibition in wet and salt-laden environments. Used by the Royal Australian Navy, commercial marine operators, and mining teams in coastal Queensland. Works via Polar Bonding — molecules orient perpendicular to the metal surface, forming a persistent barrier against moisture and oxygen. More expensive than INOX or CRC; the right choice for severe environments where the cost of corrosion damage justifies the premium. Available at AIMS Industrial. Rocol UK industrial brand with strong Australian trade distribution. Rocol's spray range focuses on specific industrial applications: dry PTFE spray, chain lubricants, anti-corrosion coatings, and food-grade lubricants. Rocol Dry PTFE Lubricant is the standard choice for cable and lock applications in Australian maintenance workshops. Available at AIMS Industrial. Molytec, Dy-Mark, and Helmar Molytec produces molybdenum disulphide-based lubricants and anti-seize compounds for extreme-pressure assembly applications — not penetrating oils. When you free a seized fastener, applying a Molytec anti-seize on reassembly prevents recurrence. See the Anti-Seize Compound Guide for selection guidance. Dy-Mark and Helmar are general Australian industrial maintenance spray brands offering penetrant, silicone lubricant, contact cleaner, and dry lubricant options — suitable for standard applications. When to Use Penetrating Oil vs Lubricant: Decision Guide The following table covers the most common maintenance spray situations in Australian trade and industrial environments, with the correct product type and notes for each. Situation Correct Product Notes Seized or rusted bolt/nut Penetrating oil (CRC 5-56, INOX MX3) Apply, wait minimum 20 minutes, reapply. See technique section below. Hinge needing long-term fix White lithium grease or silicone spray Penetrant evaporates. Use grease for metal-on-metal, silicone for plastic/rubber hinge components. Bicycle or motorcycle chain Dedicated chain lube (wet or dry) WD-40 strips existing lube. Use dry lube in dusty conditions, wet lube in wet or heavy-load conditions. Door and window runners/tracks Silicone spray No oil staining on rubber seals or plastic tracks. Electrical connections — moisture WD-40 or CRC 5-56 Short-term. For outdoor or marine connections, use CorrosionX for lasting protection. Metal-on-metal sliding (guide rails) Silicone spray or dry PTFE Oil attracts grit in workshop environments. Dry film preferred. Marine fittings and rigging INOX MX3 or CorrosionX Salt-resistant formulation essential. Food processing machinery Lanox (INOX MX7) or NSF H1 lubricant Legal and HACCP requirement. No petroleum products. High-load fastener assembly Anti-seize compound (Molytec, Loctite) Prevents seizing on reassembly. Different application, different timing. Rusty tools — clean and protect CRC 5-56 or WD-40 to clean, INOX MX3 for storage protection Two-step: clean the rust, then apply a protective coat. Cable inners and brake cables Dry PTFE spray Oil lubricants collect grit inside cable housing and cause premature wear. Locks and padlocks Dry PTFE or graphite spray Oil lubricants gum up lock internals over time. Rubber seals and O-rings Silicone spray Petroleum solvents degrade rubber compounds. Silicone is compatible with most seal rubbers. Plastic sliding or moving parts Silicone spray Petroleum solvents can craze some plastics. How to Use Penetrating Oil on Seized Bolts and Rusted Fasteners The majority of penetrating oil failures are technique failures, not product failures. The single most common mistake is applying the product and trying to turn the fastener within 30 seconds. Penetrating oil requires time to work. Penetrating oil is the foundation of every fastener removal procedure. For the dedicated stud and broken-fastener removal techniques (cam-grip extractors, weld-a-nut method, drilling out), see our Stud Extractor Guide; if extraction damages the parent thread, our Stripped Thread Repair Guide covers the Recoil and Helicoil thread insert recovery. Step 1: Clean the area Remove loose rust, dirt, and grease from around the fastener before applying penetrant. The fluid needs to reach the thread contact interface — surface contamination slows penetration. A wire brush or rag is sufficient. Step 2: Apply at the thread interface Direct the spray at the point where the fastener enters the nut or casting — the thread contact line — not just the head of the bolt. If it has a nut, spray both the top and bottom thread interfaces. Penetrant needs to wick into the gap between male and female thread. Step 3: Wait — this is the critical step Minimum wait for mild rust: 15–20 minutes. Heavy corrosion: reapply every 20 minutes for 2–4 hours. Severely seized fasteners: reapply and leave overnight. The capillary action that drives penetrant into the thread gap is slow. Impatience is the primary cause of stripped bolt heads and broken fasteners. Step 4: Apply heat if available Heat expands metal and opens the joint, allowing penetrant to wick deeper. Use a gas torch or heat gun — not an open flame near aerosol penetrant. Apply heat to the nut (outer component), not the bolt where possible. Allow the joint to cool slightly before attempting to turn — the contraction cycle helps break the rust bond. Do not apply aerosol penetrant to a component that is still hot. Step 5: Apply shock and work back-and-forth An impact wrench (rattle gun) is more effective than sustained hand torque — the shock loading disrupts the rust bond rather than just applying continuous rotational force that strips the head. If using hand tools, apply a sharp hammer blow to the head of the bolt before using the wrench. Work the fastener in both directions rather than trying to undo it in one continuous rotation — tighten slightly, then loosen. The alternating motion scrubs corrosion off the thread contact surfaces. Step 6: When it still will not move Options: a longer overnight soak, a nut splitter (cuts the nut off without damaging the stud), a bolt extractor (left-hand drill bit and extractor socket for broken bolts), or cutting and welding a new nut onto a rounded fastener. If the screw won't turn because it's a one-way (clutch-head) security screw rather than a seized one, no amount of soaking or heat will help — see our One-Way Screw Removal Guide for the removal methods that actually work on these. Once free, apply anti-seize compound on reassembly to prevent recurrence. See the Anti-Seize Compound Guide and note that torque values for dry threads do not apply directly when anti-seize is used. For thread locking and sealing information see also the Thread Locking & Sealing Guide. Silicone Spray Lubricant: What It Is and When to Use It Silicone spray is not a penetrating oil and not a general-purpose lubricant substitute for WD-40 — it deposits a silicone polymer film that's petroleum-free, non-greasy and safe on rubber, vinyl and most plastics, making it the right choice for door and window seals, tracks and runners, conveyor belts and plastic-on-plastic contact. Keep it away from anything due to be painted or glued, and away from electrical switches and connector contacts. For the full picture — properties, application technique, food-grade options, and exactly where it should and shouldn't go — see our Silicone Spray Guide. Dry Lubricant Spray: Best Applications Dry lubricant sprays are underused in Australian workshops — partly because they are less familiar, partly because the invisible dry film makes people assume they have not worked. They are essential where oil-based lubricants attract contaminants or leave unacceptable residue. How dry PTFE spray works PTFE particles suspended in a fast-evaporating carrier solvent. Apply, wait 5–10 minutes for the solvent to evaporate, and a dry, invisible PTFE film remains. PTFE has one of the lowest friction coefficients of any solid material. The film is dry — it does not attract dust, grit, or metal particles. In dusty environments, a wet lubricant can turn into an abrasive paste of oil and airborne particles; a dry PTFE film lubricates without creating a contamination trap. Best applications Cable inners: Inner wire cables in machinery, bicycle brake and gear cables, vehicle handbrake cables. Apply to the inner wire before threading through the housing. Locks and padlocks: The correct lubricant for lock mechanisms. Oil lubricants dissolve factory grease in pin tumblers and collect dirt — over time making locks stiffer. PTFE spray or graphite powder is the standard lock lubricant. Bicycle chains (dry conditions): On gravel, trail, and dry-road bicycles, PTFE dry chain lube keeps the drivetrain clean. Switch to wet chain lube in wet or muddy conditions. Woodworking jig tables and fences: Dry film on cast iron table surfaces keeps workpieces sliding smoothly without oil contamination of the timber. Drawer slides, sewing machine mechanisms, precision equipment: Applications where cleanliness and residue-free lubrication matter. Not suitable for high-load applications (insufficient film strength) or wet/muddy conditions where the film washes off. Product Comparison: WD-40, 3-in-1, CRC 5-56, INOX MX3, Silicone Spray Product Type Primary Use Rubber/Plastic Safe Food Safe Long-Term Protection WD-40 Original Multipurpose penetrant/WD Moisture displacement, light penetration Limited No Poor — evaporates CRC 5-56 Penetrating oil / WD Penetration, moisture displacement Limited No Fair INOX MX3 Penetrant + corrosion inhibitor Penetration + lasting corrosion protection Yes (check SDS) No Good INOX Lanox MX7 Food-grade penetrant/lubricant Food processing, agriculture Yes Yes — H1 Good CorrosionX Penetrant + corrosion inhibitor Marine, aviation, severe environments Yes No Excellent 3-in-1 Oil Light machine oil General lubrication, hinges, sewing machines No (petroleum) No Fair — heavier than WD-40 Silicone spray Silicone lubricant Rubber, plastic, tracks, seals Yes No (check product) Good Rocol Dry PTFE Dry lubricant (PTFE) Cables, locks, clean environments Yes Some grades yes Moderate Molytec products Anti-seize / assembly lubricant High-load fastener assembly, extreme pressure Depends on grade Some grades Very good WD-40 vs 3-in-1 Oil 3-in-1 Oil (originally a blend of oil, lubricant, and rust preventive) is a light machine oil with a heavier base oil than WD-40's light mineral oil. For lubrication of precision mechanisms, hinges, and light machinery, 3-in-1 is a better choice than WD-40 because its heavier oil does not evaporate as quickly. For penetrating rust and displacing moisture, WD-40 is the better choice. Neither is suitable for heavy-duty lubrication or hostile environments. For a broader overview of industrial lubricant types and selection criteria, refer to the Industrial Lubricants Guide. Penetrating Oil Safety and Storage Aerosol penetrating oils and spray lubricants contain petroleum-based solvents and pressurised propellants. Standard precautions apply. Flammability: Most aerosol penetrants — WD-40, CRC 5-56, INOX MX3 — are flammable. Do not apply near open flames, welding arcs, or grinding sparks. Aerosol cans must not exceed 50°C. CorrosionX has a higher flash point and is classified as non-flammable in aerosol form in most jurisdictions — check the SDS. Ventilation: Aerosol mist in a confined space creates an inhalation risk from petroleum solvent vapours. Use in well-ventilated areas. In enclosed spaces (vessel interiors, pits, confined workshops), provide mechanical ventilation and wear respiratory protection for organic solvent vapours. The relevant Australian standard for confined space entry is AS 2865. Skin and eye contact: Wash skin thoroughly after prolonged contact — use a workshop industrial hand cleaner (citrus or walnut-shell formulation) rather than dish soap; petroleum distillates strip the skin lipid barrier on contact. Nitrile gloves provide adequate protection for most spray lubricant handling. For eye contact, flush with clean water for at least 15 minutes and seek medical assessment. Storage: Store upright in a cool, dry location away from direct sunlight, heat sources, and ignition sources. Partially full cans are hazardous waste — do not place in general waste or recycling. Empty cans can be recycled via most council kerbside programs. SDS documents for all products stocked at AIMS Industrial are available on request. Frequently Asked Questions What is penetrating oil used for? Penetrating oil is used to free seized, rusted, or corroded fasteners and joints — bolts, nuts, hinges, and pivots that have corroded together and cannot be turned by normal force. It contains solvents and surfactants that wick into the microscopic gap between corroded metal surfaces and break the rust bond. Secondary uses include moisture displacement from electrical connections, light corrosion protection on bare metal, and cleaning adhesive residue. Penetrating oil is not a long-term lubricant — use a proper grease or oil-based lubricant for ongoing lubrication needs. Is WD-40 a penetrating oil or a lubricant? WD-40 is primarily a water-displacement fluid and light penetrating oil. The name stands for "Water Displacement, 40th formula." It does provide short-term lubrication through a light mineral oil component, and WD-40's own website acknowledges this. However, that mineral oil evaporates relatively quickly, so WD-40 Original is not suitable as a long-term lubricant for chains, bearings, hinges, or any application requiring a lasting film. For long-term lubrication, use a dedicated lubricant — white lithium grease, chain lube, grease, or machine oil depending on the application. What is the difference between WD-40 and 3-in-1 Oil? WD-40 is primarily a water-displacement penetrant — it excels at displacing moisture and freeing mildly corroded components, but its light oil evaporates and does not provide lasting lubrication. 3-in-1 Oil is a light machine oil with a heavier base oil that persists longer as a lubricant. For penetrating rust and moisture displacement, WD-40 is the better choice. For lubricating precision mechanisms, sewing machines, hinges, and light machinery where a thin, persistent oil is appropriate, 3-in-1 is a better choice than WD-40. Neither product is suitable for heavy-duty lubrication or harsh environments. Is CRC 5-56 the same as WD-40? CRC 5-56 and WD-40 Original are similar in function — both are petroleum-based water-displacement penetrating oils — but they are different products with different formulations. CRC 5-56 has slightly better corrosion inhibition in its carrier oil and is preferred in Australian trade environments, particularly by electricians and maintenance fitters. WD-40 has greater consumer brand recognition. For most standard penetrating and moisture-displacement tasks, either product is acceptable. For better corrosion protection or more demanding penetration, INOX MX3 outperforms both. What is INOX MX3 used for? INOX MX3 is an Australian-made penetrating oil, lubricant, and corrosion inhibitor in one product. It is used for freeing seized and rusted fasteners, displacing moisture from electrical connections, protecting metal surfaces from corrosion, lubricating hinges and pivots, and maintaining marine and agricultural equipment. Its primary advantage over WD-40 and CRC 5-56 is a less volatile carrier oil that provides lasting corrosion protection after application, rather than evaporating and leaving bare metal. INOX MX3 is generally safe on rubber and most plastics (check the product SDS for specific polymer compatibility). When should I use silicone spray instead of WD-40? Use silicone spray instead of WD-40 when the surface is rubber, plastic or vinyl, or when you need a long-lasting, non-greasy film rather than a penetrant that evaporates. Typical applications are door and window seals, tracks and runners, and conveyor belts. Don't use it near paint, adhesive or electrical switching contacts. See our Silicone Spray Guide for full application guidance, food-grade options and where it should and shouldn't go. Can I use WD-40 as a long-term lubricant? No. WD-40 Original is not suitable as a long-term lubricant. The light mineral oil component evaporates within hours, leaving inadequate lubrication and, in some cases, bare metal that is more susceptible to rust than before. For long-term lubrication, choose the product appropriate to the application: white lithium grease spray for metal hinges and sliders, chain lube for chains, silicone spray for rubber and plastic tracks, or grease for bearings and heavily loaded pivots. The WD-40 Specialist range includes purpose-built lubricants that are far more suitable for sustained lubrication than WD-40 Original. What is the best penetrating oil for seized bolts? For lightly corroded fasteners, CRC 5-56 or WD-40 Specialist Penetrant perform adequately. For heavily seized or badly rusted fasteners, INOX MX3 or CorrosionX provide better penetration combined with corrosion protection after the joint is freed. The technique matters as much as the product: apply generously, wait at least 20 minutes (2–4 hours for severe corrosion), reapply, apply heat if possible, and use an impact wrench rather than sustained hand torque. Overnight soaking with multiple applications is the most effective approach for heavily corroded fasteners. What is dry lubricant spray best used for? Dry lubricant spray (PTFE/Teflon-based) is best used in applications where wet lubricants attract contaminating dust, grit, or debris. Common applications include cable inners and cable housings, locks and padlocks, bicycle chains in dry/dusty conditions, woodworking jig table surfaces, drawer slides in dusty workshops, and sewing machine mechanisms. The PTFE film is dry and invisible — it lubricates effectively without leaving a sticky residue. It is not suitable for high-load metal-on-metal contact or wet/muddy environments where the film would wash away. Is INOX food safe? INOX MX3 (the standard product) is not food safe — it contains petroleum-based components and should not be used in food-processing environments. INOX Lanox MX7 is the food-safe version: it carries H1 lubricant registration, is approved for incidental food contact, and meets FDA, USDA, and Australian food safety requirements. Lanox does not contain petroleum distillates. For any maintenance spray application in a food-processing facility, beverage plant, or food-handling environment, use Lanox MX7 or another NSF H1-registered product. How long should I leave penetrating oil on a rusted bolt? At minimum, 15–20 minutes for mildly rusted fasteners. For moderate corrosion, reapply every 20 minutes over 2–4 hours. For severely seized bolts — rusted solid or corroded into a casting — apply generously and leave overnight, reapplying before bed and again in the morning before attempting to turn. Most penetrating oil failures are the result of trying to turn the fastener within the first 30–60 seconds. The capillary action that drives penetrant into the thread gap requires time. Patience is the most effective penetrating oil technique. Can I use penetrating oil on bicycle chains? No — do not use penetrating oils such as WD-40 or CRC 5-56 as regular bicycle chain lubricants. Penetrating oils strip the factory lubricant from inside the chain's rollers and pins, leave a thin film that evaporates quickly, and leave the chain worse off than before. Use a purpose-formulated bicycle chain lubricant: dry chain lube (PTFE/wax-based) for dry and dusty conditions, or wet chain lube (oil-based) for wet weather and heavy-duty riding. If you have used WD-40 to clean a chain, allow it to evaporate fully, then apply a proper chain lubricant before riding. What is penetrating oil used for? Penetrating oil is a low-viscosity lubricant designed to creep into the narrow gaps between rusted, seized or corroded fasteners. It works by capillary action — wicking into the thread gap and breaking down rust at the contact surfaces — so that a stuck nut, bolt or fitting can be freed without snapping the fastener. Common uses include freeing rusted bolts on cars and trucks, releasing seized fittings in plumbing and pneumatics, and freeing rusted pins and bushes in agricultural equipment. How long does penetrating oil need to soak? Soak time depends on how badly the fastener is seized. For lightly stuck fasteners, a few minutes is usually enough. Heavily rusted fasteners benefit from soaking for an hour or overnight, with the oil reapplied periodically as it wicks into the joint. Tapping the fastener lightly with a hammer while soaking helps the oil work into the thread gap. Don't rush — patience here saves a broken bolt. Is WD-40 a penetrating oil? WD-40 is a multi-purpose water-displacing spray that has some penetrating action, but it is not as effective as dedicated penetrating oils on heavily seized fasteners. Products specifically formulated as penetrating oils have lower surface tension and better capillary action for getting into rust. WD-40 works fine for light tasks but for badly seized bolts, use a dedicated penetrant designed for the job. Can penetrating oil damage paint or rubber? Penetrating oils based on solvents can soften some paints and degrade some rubber components if left in contact for extended periods. Wipe off any overspray promptly and avoid spraying near rubber seals, hoses or painted surfaces unless the product is specifically marked as compatible. For applications near sensitive materials, choose a penetrant marked as safe on plastic and rubber. Shop Penetrating Oils and Spray Lubricants at AIMS Industrial AIMS Industrial stocks a full range of penetrating oils, spray lubricants, and maintenance sprays for trade and industrial use — including CRC, INOX MX3, INOX Lanox, CorrosionX, Rocol, Molytec, Dy-Mark, and Helmar products. Browse the complete range, available for trade ordering and delivery across Australia. Shop Penetrating Oils & Spray Lubricants at AIMS Industrial → For guidance on the broader range of industrial lubricants — greases, hydraulic oils, gear oils, and cutting fluids — see the Industrial Lubricants Guide. For hydraulic system-specific oil selection, see the Hydraulic Oil Guide. The full lubrication product range at AIMS covers everything from aerosol sprays to bulk drum supply. Pair this with cable-protection gear — see the AIMS grommets collection.
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Weld Like A Pro With CRC Weld-Aid®
The new and improved Weld-Aid® product range is “engineered to improve your welding productivity”, so you can do easier and cleaner welds. They are specifically designed for MIG welding. Nozzle-Kleen Nozzle-Dip HD Nozzle-Kleen #2 Weld-Kleen Weld-Kleen HD Weld-Kleen Anti-Spatter 350 Lube-Matic Wire Kleener and Lubricant Kleener Pads (Red) Lube Pads (Black) Combo Pack (Red and Black) Nozzle-Kleen This product group consists of the Nozzle Dip HD and Nozzle Kleen #2. These are engineered to prevent, reduce and remove spatter build-up on your welder nozzles, tips and diffusers, so you can use them longer. Nozzle-Dip HD It will neither clog your torch, nor contaminate your weld like petroleum jelly (from which most conventional nozzle dips are made), thanks to its unique water-based gel formulation. More benefits: Effectively cools your nozzles and tips Reduces spatter build-up Works on both hot and cold torches Does not drift into the liner Water-based Biodegradable Non-flammable Non-hazardous Non-flashing Non-toxic Paintable Buy the CRC Nozzle-Dip HD. Nozzle-Kleen #2 All you need is a light spray of "the world’s best-selling anti-spatter aerosol” on the nozzle, and you can start welding right away. More benefits: Can be used even on surfaces to be welded Spatter can easily be wiped away No need to scrape or grind the finish Leaves less smoke and odor Dries quickly Does not contain fluorocarbons Non-flammable Paintable Buy the CRC Nozzle-Kleen #2. Weld-Kleen This product group consists of the Weld-Kleen HD and Weld-Kleen Anti-Spatter 350. Use them if you want to spend more time welding and less time on grinding and cleaning up spatter. Weld-Kleen HD It protects your welder’s parts as well as your clamps, tooling and other fixtures with its heavy-duty base metal treatment. More benefits: Accepts pre-heating Dries quickly Non-flammable Paintable Buy the CRC Weld-Kleen HD. Weld-Kleen Anti-Spatter 350 It has a “superior performance versus other water-based anti-spatters". More benefits: Available in non-pressurized and pressurized (aerosol) dispensers Spatter just wipes away (no need to scrape and grind) Effective for use in torch blow-down systems Ready to use, no need to mix Environmentally friendly Biodegradable Non-hazardous Non-toxic Paintable Buy the CRC Weld-Kleen Anti-Spatter 350. Lube-Matic This product group consists of the Wire Kleener and Lubricant and Kleener Pads. Use them if you want to improve the lifespan of your tips and liners for up to 300%. Wire Kleener and Lubricant This easy-to-use welding wire cleaner and lubricant is designed to promote smoother wire feeding (specifically, fabricated and mild steel wires) by reducing drag and friction from the feeder to your welder. It is applied to Kleener Pads as needed (see below). More benefits: Decreases downtime caused by wire jamming Helps feed fabricated and mild steel wires Reduces wire drag by up to 60% Removes dirt Cuts rusts Buy the CRC Wire Kleener and Lubricant. Kleener Pads (Red) and Lube Pads (Black) Applied with the Wire Kleener and Lubricant, these pads will help keep your wires thoroughly cleaned and lubricated to maximise your torch’s effectiveness and lifespan. You can buy them separately or as a bundle. More benefits of Kleener Pads (Red): Reduce burnback by up to 50% Effective for all wire types Excellent with aluminium Buy the CRC Kleener Pads (Red). More benefits of Lube Pads (Black): Effective pre-treatment for smoother feeding of wires with poor cast, helix and rust Good for long feed liners Best used for the pre-treatment of wires Can be used on all types of steel wires (but not recommended with aluminium) Buy the CRC Lube Pads (Black). *Need help with a purchase decision? Contact us directly via chat or send an email to sales@aimsindustrial.com.au or call us on (02) 9773 0122 Need welding gear? The AIMS Welding collection covers everything from entry-level inverters to multiprocess welders. AIMS stocks a comprehensive Lubrication collection — Loctite, Anglomoil, Macnaught, Triple7 and CRC products. Looking for butt weld fittings? Our butt weld fittings range covers the common sizes and brands. People Also Ask — Weld Aid Anti-Spatter Products Q: What does weld spatter protection spray do? Weld anti-spatter spray is applied to the workpiece and surrounding areas before welding to prevent molten metal droplets from adhering to the surface. After welding, spatter falls away cleanly instead of bonding to the steel, dramatically reducing post-weld clean-up time and protecting adjacent surfaces from surface contamination. Q: Can weld anti-spatter be used inside the MIG gun nozzle? Yes, nozzle-dip anti-spatter products are specifically formulated for applying to or dipping the MIG gun nozzle to prevent spatter build-up inside the nozzle and on the contact tip. This extends nozzle and tip life, maintains shielding gas flow and reduces downtime for nozzle cleaning during extended welding operations. Q: Is weld anti-spatter spray safe to use on stainless steel? Standard petroleum or silicone-based anti-spatter products should not be used on stainless steel that will be painted or coated afterward, as silicone contamination causes fish-eye defects in coatings. Water-based or silicone-free anti-spatter products are available specifically for stainless steel applications. Q: How should anti-spatter spray be applied for best results? Apply a thin, even coat to the workpiece surface before welding, allowing it to flash off briefly if specified by the manufacturer. Avoid spraying directly onto the weld zone or joint gap as this can contaminate the weld and cause porosity. Nozzle dip products should coat the inside of the nozzle without blocking the gas outlet holes.
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