Roller chain selection starts from the transmitted power, the speed of the small sprocket and the service factor of the driven machine. This guide walks through the steps our engineers use when sizing a chain drive.

1. Define the duty

• Motor power (kW) and small sprocket speed (rpm)
• Load character: smooth, moderate shock or heavy shock
• Daily running hours and environment (dust, moisture, temperature)

2. Choose pitch and number of strands

Multiply the motor power by the service factor to get the design power, then pick the smallest pitch whose rating covers it. If the pitch becomes too large for the available space, move to a duplex or triplex chain.

3. Sprocket teeth and ratio

Use at least 17 teeth on the small sprocket for normal speeds and 21+ for high speeds. Keep the ratio below 7:1 for a single stage.

4. Centre distance and lubrication

A centre distance of 30–50 pitches is ideal. Provide regular lubrication: drip or oil bath for medium speeds, forced lubrication for high speeds.

Send us your operating data and our team will confirm the chain and sprocket combination.