Chain & Sprockets

A chain and sprocket drive transmits rotary power from one shaft to another using a positive mechanical link, rather than the friction grip of a belt. The chain's rollers seat into the sprocket teeth, so there's no slip under load — torque goes in one end and comes out the other at a fixed ratio, cycle after cycle. That's why chain drives turn up wherever a belt would slip, stretch or perish: conveyors, agricultural machinery, packaging lines, pumps, mixers, and general workshop drive systems across Australian industry. We've put together a Roller Chain: Sizes, Types & Sprockets if you'd like more detail before you buy.

AIMS Industrial stocks a genuinely deep chain and sprocket range — 243 products spanning British Standard (BS) and American Standard (ASA/ANSI) roller chain in simplex, duplex, triplex and quad strand, connecting links and offset (half/crank) links, leaf chain, stainless steel and nickel-plated chain for corrosive or washdown environments, agricultural chain, and the full family of sprockets — taper lock, pilot bore, weld-fit and plate wheel — plus idler sprockets, chain tensioners, chain pullers and chain breakers. This page is the hub for the whole category: use it to get your bearings on chain pitch, standards and selection, then jump into the specific sub-range you need.

Chain Types at a Glance

Choosing the Right Chain and Sprocket

Pitch and standard — BS vs ASA/ANSI

Pitch is the centre-to-centre distance between adjacent chain pins, and it's the number that has to match exactly between chain and sprocket. British Standard (BS, to ISO 606) is the dominant system in Australian industrial plant; American Standard (ASA, to ANSI B29.1) turns up mostly on US-spec and imported equipment and a good deal of agricultural machinery. The two systems overlap in nominal pitch at several sizes but are not interchangeable — roller diameter and inner plate width differ even when the pitch number looks the same, so BS 08B and ASA #40 (both roughly 1/2" pitch) will not run cleanly on each other's sprockets.

Always confirm pitch by measuring across several pins with callipers rather than guessing from chain "size" alone, and check for stamped markings on the sprocket or chain plates where they exist.

Strand count — simplex, duplex, triplex, quad

Simplex is a single strand and covers most general workshop drives. Duplex and triplex chain run two or three strands side by side on common pins, roughly doubling or tripling load capacity for a given pitch — useful when a single-strand chain at the next pitch up would need an awkwardly large sprocket or centre distance. Quad (four-strand) chain sits at the top of that range for heavy agricultural and industrial loads. Strand count has to match on both chain and sprocket — a duplex chain needs a duplex sprocket with two rows of teeth, not a simplex sprocket run twice.

Sprocket type — taper lock, pilot bore, weld-fit, plate wheel

Taper lock sprockets use a separate tapered bush to clamp onto the shaft, so the same sprocket bore can suit a range of shaft diameters and the bush can be swapped without removing the sprocket from the chain — the most maintenance-friendly option where shafts get serviced regularly. Pilot bore sprockets are supplied with a small bore for the workshop to machine out and key to the exact shaft size — useful where a non-standard bore or keyway is needed. Weld-fit sprockets are welded directly and permanently to the shaft or hub, chosen where taper lock or pilot bore mounting isn't practical. Plate wheel sprockets are a simpler, flat pattern often used on lighter drives and idlers. Sprocket tooth count sets the drive ratio in combination with the driven sprocket, and running too few teeth on a fast-turning sprocket increases chordal action and wear — as a general rule, more teeth on the drive sprocket means smoother, longer-lived running.

Material — steel, stainless and nickel-plated

Standard carbon steel chain and sprockets suit the vast majority of dry, indoor industrial drives. Stainless steel chain and connecting links are the right call for washdown areas, food-adjacent equipment, coastal sites, or anywhere corrosive contamination is a real risk — AIMS stocks stainless roller chain and matching stainless connecting/offset links across several pitch sizes. Nickel-plated chain gives a lighter-duty corrosion buffer at a lower cost than stainless, suited to mildly damp or humid environments rather than genuine washdown or chemical exposure.

Lubrication

Roller chain needs oil to penetrate the pin-and-bush joint, not just coat the outside — a running chain with no lubrication reaching that joint wears out far faster than the same chain properly oiled, regardless of how clean it looks. See our lubrication range for chain oils suited to your operating temperature and environment, and consider a self-lubricating chain (AIMS stocks these in ASA simplex) for drives that are hard to access for routine oiling.

Common Applications

Chain and sprocket drives are everywhere in Australian trade and industrial settings: conveyor systems in processing and packaging lines, general machinery drives on pumps, mixers and fans, agricultural equipment (balers, harvesters, augers — where quad-rivet and heavy-series ASA/BS chain is common), forklift masts and lift mechanisms (leaf chain rather than roller chain), and as the mechanical drive inside chain blocks and lever hoists. Idler and tensioner sprockets keep chain tension correct on long or variable-load spans, and connecting or offset links let a workshop join or shorten a chain run on site without sourcing a custom length.

Chain Wear, Inspection and Maintenance

Roller chain wears at the pin-and-bush joint as it runs, and that wear shows up as elongation — the chain gets measurably longer than its new pitch length. Once elongation passes roughly 2–3% of the original pitch length, the chain starts riding up on the sprocket teeth instead of seating properly, accelerating wear on both chain and sprocket and raising the risk of a sudden jump or failure. Practical checks worth building into a maintenance routine:

• Measure elongation across a set number of pitches with a ruler or purpose-made chain wear gauge, and compare against the chain's new length.
• Look at the sprocket teeth for a hooked or "shark fin" profile — a sign the chain has been riding high and wearing the tooth face unevenly.
• Check tension — most horizontal drives want roughly 1–2% of centre distance as slack-side sag; too tight loads bearings and accelerates chain stretch, too loose risks the chain jumping teeth.
• Check alignment between drive and driven sprockets with a straightedge — misalignment wears one side of the chain and sprocket teeth faster than the other and is a common, easily-missed cause of premature failure.
• Replace chain and sprockets together where either shows real wear — a new chain run on worn sprockets wears out again quickly, so the saving from reusing tired sprockets is rarely worth it.

Brands Stocked at AIMS

Across the 243 products in this range, two chain manufacturers make up the large majority of the catalogue, with a specialist sprocket and chain-accessory supplier rounding out the mounting hardware side:

• SY Chain — around 103 products (roughly 42% of the range): the broadest single-brand spread, covering BS and ASA roller chain across simplex through quad strand, leaf chain, double-pitch and stainless variants, and the matching connecting and offset links.
• KCM — around 96 products (roughly 40%): BS and ASA roller chain including cottered, H-type, HE-type, hollow pin, side bow, X-ring and self-lubricating variants, nickel-plated and stainless chain, leaf chain, and connecting/offset links.
• Finer Power Transmissions — around 33 products (roughly 14%): the specialist sprocket brand in this range, supplying taper lock, pilot bore, weld-fit and plate wheel sprockets in steel and cast iron, plus idler sprockets, chain pullers and chain breakers.
• Agri-Power and ECO — a small, focused range of agricultural quad-rivet roller chain for balers, harvesters and similar equipment.

Between SY Chain and KCM, AIMS covers essentially every common BS and ASA roller chain configuration a trade or maintenance buyer is likely to need, with Finer Power Transmissions supplying the sprockets to match.

Browse Chain & Sprockets by Type

This page covers the category as a whole — for the full listing of a specific chain or sprocket type, head into the relevant range:

• Roller Chain — BS and ASA roller chain in all strand counts and configurations
• Sprockets — taper lock, pilot bore, weld-fit and plate wheel sprockets
• Roller Chain Links — connecting links and offset/half (crank) links
• Stainless Steel Roller Chain — for washdown and corrosive environments
• Leaf Chains — AL and BL series for forklift masts and similar equipment
• Agricultural Chain — quad-rivet chain for balers, harvesters and augers
• Chain Idlers & Accessories — idler sprockets, tensioners, chain pullers and breakers
• Lifting Chain Links — WLL-rated links for lifting applications, not drive chain
• Chain Blocks and Chain Lever Blocks — lifting and hoisting equipment

Also see related power transmission ranges: couplings, V-pulleys and industrial V-belts.

Frequently Asked Questions

What's the difference between BS and ASA roller chain?

BS (British Standard, to ISO 606) and ASA (American Standard, to ANSI B29.1) are two different roller chain sizing systems. BS is the dominant standard in Australian industrial plant; ASA is common on US-spec and imported machinery and a lot of agricultural equipment. They're not interchangeable — even at the same nominal pitch, roller diameter and plate width differ, so a chain from one system won't run properly on a sprocket from the other.

How do I identify the pitch of a chain I need to replace?

Pitch is the centre-to-centre distance between adjacent chain pins. Measure across several pitches with callipers for accuracy rather than a single link, since small measurement errors compound. Check for any stamped size markings on the chain plates or the old sprocket first — that's the fastest way to confirm the exact designation before measuring.

Should I replace just the chain, or the chain and sprockets together?

If the sprocket teeth show any real wear — a hooked or pointed profile — replace both. Chain wear and sprocket wear happen together, and a new chain run on worn sprockets wears out again quickly, so the cost saving from reusing tired sprockets rarely pays off.

What's the difference between simplex, duplex and triplex chain?

Simplex is a single strand and covers most general workshop drives. Duplex (two strands) and triplex (three strands) run side by side on shared pins, increasing load capacity for the same pitch. They need matching duplex or triplex sprockets — a wider chain needs a wider-toothed sprocket, not a simplex sprocket run twice.

What is a taper lock sprocket and why use one?

A taper lock sprocket mounts via a separate tapered bush rather than a machined bore, so the sprocket can be fitted and removed without pulling it off the chain, and the same sprocket bore accommodates a range of shaft sizes depending on the bush fitted. It's the preferred choice for drives that get serviced regularly.

What's the difference between a pilot bore and a weld-fit sprocket?

A pilot bore sprocket ships with a small bore that the workshop machines and keys out to the exact shaft dimension, giving flexibility for non-standard shafts. A weld-fit sprocket is welded directly and permanently to the shaft or hub — used where taper lock or pilot bore mounting isn't practical, common on conveyor and agricultural drives.

When should I replace a worn roller chain?

Once a chain has elongated roughly 2–3% beyond its new pitch length, it starts riding up on the sprocket teeth rather than seating fully, which accelerates wear on both chain and sprocket. Measure elongation across a known number of pitches with a ruler or chain wear gauge and compare to the new-chain length; don't wait for visible failure.

How much sag should a roller chain drive have?

Most horizontal drives want roughly 1–2% of the centre distance as slack-side sag. Too tight loads the shaft bearings and stretches the chain prematurely; too loose risks the chain whipping or jumping the sprocket teeth. Vertical and near-vertical drives generally need less sag than horizontal ones.

Why does chain and sprocket alignment matter?

Misaligned drive and driven sprockets force the chain to run at a slight angle across the teeth, wearing one side of the rollers, bushes and teeth faster than the other. Check with a straightedge across both sprocket faces and confirm the shafts are parallel — it's a quick check worth doing before commissioning any new drive.

What lubricant should I use on a roller chain?

The lubricant needs to reach the pin-and-bush joint, not just coat the outside of the chain — that's the actual wear surface. See our lubrication range for chain oils suited to your operating temperature and environment. AIMS also stocks self-lubricating ASA roller chain for drives that are hard to access for routine oiling.

What is leaf chain used for?

Leaf chain (AL light-duty and BL heavy-duty series in this range) is built differently to roller chain — it's a series of pin-jointed link plates rather than rollers — and is typically used in forklift masts and lift-cylinder mechanisms rather than as a rotary power transmission chain.

Is drive chain the same as lifting chain?

No. Roller chain, leaf chain and drive sprockets are rated for power transmission duty, not overhead lifting. WLL (Working Load Limit)-rated lifting chain, slings and the load chain in chain blocks and lever hoists are separately manufactured and rated for lifting duty. Never substitute one for the other.

When should I use stainless steel roller chain instead of standard steel?

Choose stainless steel chain for washdown areas, food-adjacent equipment, coastal sites, or anywhere corrosive contamination is a genuine risk to a standard steel chain's service life. For mildly damp or humid environments that don't involve washdown or chemical exposure, nickel-plated chain is a lower-cost alternative.

What quantities does roller chain come in?

Roller chain in this range is available by the box (commonly 10-foot and up to 50 or 100-foot box quantities depending on chain size) as well as connecting and offset links sold individually — useful for workshops stocking spares ahead of scheduled maintenance as well as one-off repairs.