Bushed Chain vs Roller Chain: Differences, Wear Measurement and When to Replace a Conveyor Chain

Bushed chains and roller chains look similar, but they behave differently in service. Choosing the wrong type, or running a chain past its wear limit, leads to unplanned stops, damaged sprockets and expensive repairs. This guide explains the difference, how to measure wear and when a conveyor chain should be replaced.

VBN Vertriebs GmbH supplies original AUFT bushed conveyor chains, roller chains, special chains and sprockets from Germany. If you already know what you need, send us your data and we will quote.

Bushed chain versus roller chain

Bushed chain (no rollers): the bushing is in direct sliding contact with the sprocket tooth and with the track. The design is simple and robust. It is typically used for slow, heavy conveying and in dirty, dusty or abrasive environments where rollers could clog.
Roller chain: a roller rotates around the bushing. Rolling instead of sliding reduces friction and wear on sprocket teeth and guide rails. Roller chains are common in drives and in conveyors that run faster or must run quietly.

As a general guide, choose a bushed chain where load and contamination dominate and speed is low. Choose a roller chain where speed, efficiency and low wear on the sprockets matter. The right choice always depends on load, speed, environment and lubrication, so please describe your application when you ask for a quote.

How chain wear shows up

Most wear happens inside the joint, between pin and bushing. With every movement the joint loses a little material and the chain becomes longer, even though the plates look fine from outside. This is called elongation. Typical warning signs are:

The chain sits higher on the sprocket teeth or hooks into them
Noise, jerky running or whipping on long strands
Stiff or seized joints, rust or dried-out lubricant
Worn or polished contact surfaces on plates, rollers and bushings
Cracked, bent or loose attachments and carriers
Sprocket teeth with a hooked or sharp profile

How to measure elongation

Lay the chain straight or tension it lightly to its normal operating tension.
Measure the distance over a defined number of links, for example 10 or 20, from pin centre to pin centre.
Calculate the nominal length: number of links multiplied by the nominal pitch.
Elongation in percent = (measured length − nominal length) ÷ nominal length × 100.

Example: 10 links with a nominal pitch of 50 mm should measure 500 mm. If you measure 510 mm, the chain has stretched by 2 %.

When to replace the chain

A common rule of thumb for roller chains is to plan the replacement at about 2 to 3 % elongation. For long conveyor strands, tight tolerances, carriers or synchronised strands the limit can be lower. The exact limit for your chain should always be confirmed with the manufacturer. Replace earlier if you see cracks, stiff joints, damaged attachments or if the chain no longer runs cleanly on the sprocket.

Replace sprockets together with the chain

A stretched chain wears the sprocket teeth, and a new chain on worn sprockets wears out much faster. Check the sprockets at every chain change. If the teeth are hooked, thinned or polished, replace the sprockets together with the chain.

How to extend chain life

Lubricate at regular intervals with a lubricant suitable for the temperature and environment.
Keep chain tension within the recommended range and check alignment of sprockets and tracks.
Remove dust, chips and process residues from the chain path.
Inspect at fixed intervals and record the measured elongation, so you can predict the next replacement.

Plan your spare parts

Custom chains with attachments are not off-the-shelf items. For critical lines keep a spare chain or at least spare lengths, connecting links and the most worn attachments in stock, and order the next set when the measured elongation approaches the limit. Our guide on how to order a replacement conveyor chain lists the data you need for the order.

Frequently asked questions

What is the main difference between a bushed chain and a roller chain?

A bushed chain slides on the sprocket and track. A roller chain has a roller that turns on the bushing and rolls on the sprocket, which reduces friction and wear.

At what elongation should a conveyor chain be replaced?

For roller chains about 2 to 3 % is a common rule of thumb. Long or synchronised strands often need a lower limit, so confirm the value with the manufacturer.

Can I replace only the chain and keep the old sprockets?

Only if the sprockets are still in good condition. Worn sprockets damage a new chain quickly, so check them at every chain change.

Can you supply sprockets and chains together?

Yes. We supply original chains, sprockets and drive components from Germany. Please send the pitch, tooth count and bore data.

For belts, drives, sensors and safety devices for the whole line, see our overview of conveyor belt components and spare parts from Germany.

Request a quote — 24h response. Send us a drawing, a photo of the chain with a ruler, or your chain data, and we will come back with price, lead time and country of origin.