Conveyor chains: how to select a traction chain

What a conveyor (traction) chain is

A conveyor (traction) round-link chain is the traction element of continuous transport machinery. It transmits force from the drive to the working element and moves cargo or material: in bucket elevators, chain and scraper conveyors, on sawmill, sorting and packaging lines.

It differs from a load-handling chain in its duty cycle: not individual lifts, but constant operation within the mechanism — the chain runs around sprockets and pulleys, takes alternating loads and wears against the engagement. That is why for a traction chain not only strength matters, but also stable link geometry.

The conveyor versions of our plant are collected in the category Conveyor chains (traction) — it covers both lines: general-purpose round-link chains (class 3) and T8 lifting chains within the current range.

Two types of traction chains

In imported practice two families are standardised for conveyors, and they are convenient reference points when choosing:

• Long-link chain (pitch 5d, DIN 762 type) — for conveyors and bucket elevators with a coarse engagement pitch.
• Short-link calibrated (pitch about 3.5d, DIN 764 type) — for precise engagement and compact sprockets; it differs from an ordinary short-link chain in the extended pitch and calibration for stable operation in the mechanism.

DIN and EN are reference standards, not the basis of production: the products are manufactured to our technical specifications, and the final conformity to an imported size is confirmed by a technologist. Analyses of specific standards are on the pages Analogue of DIN 762 chain and Analogue of DIN 764 chain.

To which documents we manufacture

Both plant lines apply to conveyor tasks:

• TU 25.93.17-001-06515248-2020 (TU-001, strength class 3) — for standard conveyors: long-link and short-link class 3 versions, including calibrated (groups A1, A2, B1, B2);
• TU 25.93.17-002-06515248-2026 (TU-002, class 8, T8) — for heavy-duty conveyors and severe duties: short-link calibrated chains of increased strength.

The Russian regulatory framework that is convenient for comparison:

• GOST 2319-81 (for reference) — round-link load and traction chains of normal strength: type A — short-link, type B — long-link; version 1 — calibrated, version 2 — non-calibrated;
• GOST 25996-97 (ISO 610-90) — high-strength calibrated chains for mining equipment: chain and scraper conveyors, chain-and-belt conveyors, transfer conveyors, bucket elevators; gauges 14–30 mm. The standard explicitly states that such chains are not intended for lifting devices — cranes and slings. For severe traction duties the reference is our TU-002 T8 line within the range; supply specifically to GOST and gauges outside our range are clarified with a manager and a technologist.

If your documentation specifies the previous TU of the same line — TU 25.93.17-001-26518198-2016 — the products are equivalent to it in size range and load norms: we manufacture to the current TU-001, and the confirmation of technical equivalence is arranged via a manager.

What to choose from

Pitch and gauge — compatibility with the sprocket

A traction chain engages with a sprocket or runs around a pulley. The stability of the pitch determines how evenly the link enters the teeth and seats in the groove: calibrated chains hold the pitch within a narrow tolerance — the conveyor runs without jerks, wear and noise are reduced, and the sprocket's service life increases.

When selecting, verify the pitch and gauge against the parameters of the existing sprocket: even a close size with a different pitch will engage incorrectly. Designations and measurements are covered in the articles How to decode a chain designation and How to determine the size of an unknown chain; definitions of the terms — in the glossary.

Loads

The set of standardised loads is set by the TU itself:

• TU-001 (class 3): proof (WLL) and breaking (BL);
• TU-002 (T8): acceptance proof, technological and breaking; the working load is not standardised in the TU — as a guide the reference value BL/4 is used (outside the TU).

Rely on the working load with a safety factor, not on the breaking load: BL is a limit, not an operating mode. How to read the columns — in the article Chain load tables; the Selection by load tool will help you select a size by load.

Strength class and purpose

• standard conveyor, moderate loads — class 3 (TU-001);
• heavy-duty drive, severe duty, abrasive environment — T8 (TU-002) by drive calculation.

The class and size are selected by drive calculation and the link parameters, and a match of the gauge with an imported one does not by itself confirm applicability — the decision for each mechanism is confirmed by a technologist. The difference between the classes — in the article Chain strength classes.

Operating conditions and coating

• Moisture and aggressive environment. Port atmosphere, wash bays, condensation accelerate corrosion: the protective coating is galvanic zinc plating, applied as a service; more details — in the article Chain zinc plating.
• Abrasive wear. Sand, grain, ore, wood chips accelerate the wear of the links — the version is selected with the environment in mind.
• The version and coating — to the customer's specification.

Length and packaging

The chains are supplied in measured cut lengths and in whole links; winding to the customer's metreage is possible — see Round-link chains on reels. Non-standard lengths are made to the customer's parameters.

How to select a traction chain: step by step

1. Describe the mechanism. Type (bucket elevator, chain or scraper conveyor), traction force, duty, sprocket parameters, environmental conditions.
2. Measure the chain parameters if you have a sample or a worn chain: gauge d, pitch t (measure 10 links and divide by 10), outer width b, weight per 1 m. The Chain identification by measurements tool will help reduce the measurements to sizes.
3. Determine the class — class 3 or T8 — by drive calculation and duty.
4. Check the loads against the table of the corresponding TU; to convert units — the converter.
5. Agree the version: calibration, coating, length, packaging. The Chain weight and length calculator will help estimate the mass and length, and Size comparison — compare the options.
6. Send the data to a manager — they will verify the parameters, involve a technologist if necessary and prepare a quotation.

The Selection by load tool will suggest class 3 and T8 sizes with a safety factor, and Analogue selection for an imported chain — correspondences for DIN 762, DIN 764 and other standards (for reference, with a technologist's confirmation).

Operation: what to watch

A traction chain constantly works in the mechanism, so it is important to monitor its condition:

• elongation (pitch stretching) — a chain that has “lengthened” will seat in the sprocket incorrectly;
• wear of the links and rod, especially in an abrasive environment;
• cracks and weld defects;
• corrosion pits.

The basic rule: if any defect is found, the chain is taken out of service; the specific rejection criteria and inspection intervals are defined by your company's instructions. The Elongation and wear tool will help measure the elongation relative to the nominal pitch; the general inspection procedure is in the article Chain storage and inspection.

Where traction chains are used

• Ports and bulk cargo handling — ship unloaders, reclaimers, bucket elevators, scraper reclaimers: industry solution.
• Mining industry — scraper and chain conveyors, transfer conveyors: industry solution.
• Agriculture — bucket elevators and conveyors for grain and feed: industry solution.
• Logging and woodworking — sorting, debarking, sawmilling: industry solution.
• Mechanical engineering — machine assemblies and conveyor lines: industry solution.
• Water utilities and treatment plants — mechanisms in a wet and aggressive environment: industry solution.

How to order

Send us the chain parameters — gauge, pitch, link width, class, coating, required length — or a drawing (sample). For a conveyor task, add the mechanism data: traction force, duty, sprocket parameters.

• Non-standard versions are made to the customer's parameters — the Custom chain manufacturing service; parts to drawing — Manufacturing to customer drawings.
• Send the enquiry via the Contacts page. The manager will prepare the price and supply terms individually — prices are not published on the website.

A short algorithm

1. Determine the duty: standard conveyor (class 3) or high load (T8).
2. Measure the gauge, pitch, link width and weight per 1 m — or take the parameters from the mechanism's data sheet.
3. Check the pitch against the sprocket and the loads against the table of your TU.
4. Specify the coating, length and packaging.
5. Send the parameters to a manager — the selection will be confirmed by a technologist.