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Chain – Industrial Roller Chain

Chain is a component used in machines which transmits power by means of tensile forces and is used mostly for power transmission and conveyance systems. The function of chain is similar to the function of a belt.

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Chain can be categorized into five types:

  1. Cast Iron Chain
  2. Cast Steel Chain
  3. Forged Chain
  4. Steel Chain
  5. Plastic Chain

Components that make up the basic structure of Power Transmission Chain:

Connecting Link: This is the part that connects the chain together. The pin and link plate slip into the chain connecting each link of chain. This type of connecting link is 20 percent lower in fatigue strength than the chain itself, but there are some special connecting links that have the same strength as the chain.

Tap Fit Connecting Link: This link, the pin and the tap fit connecting link plate are press fit. It has fatigue strength almost equal to that of the chain.

Offset Link: An offset link is used when an odd number of chain links is required. It is 35 percent lower in fatigue strength than the chain itself. The pin and two plates slip in to fit. There is also a two-pitch offset link available that has a fatigue strength as great as the chain.

Once the link is put into place a spring clip or cotter pin is placed on the outside holding the connecting link in place.

Functions of Chain Parts:

Plate: the plate bears the tension placed on the chain. The plate must hold up to the forces of load and shock and must be resistant to corrosion, abrasion or any other environmental requirement.

Pin: The pin is subject to shearing and bending forces from the plate. The pin also forms a load-bearing part with the bushing when the chain flexes during sprocket engagement. Therefore, the pin requires high tensile and shear strength, resistance to bending and must have enough endurance against shock and wear.

Bushing: Like the pin, the bushing is subject to shearing and bending as well as shock loads when the chain engages the sprocket.
Roller – The roller handles the impact load as it meets the sprocket teeth during the chain engagement with the sprocket. After that, the roller changes its point of contact and balance. It is held between the sprocket teeth and bushings and moves on the tooth face while receiving a compression load.

Cotter Pin, Spring Clip, T-Pin: This is the point of connection that holds the out plate from falling off the pin. They could wear out during high speed operation. These parts should be heat treated.

Power transmission machines use either chains, gears, or belts to operate. Generally, chain is a more economical part of power transmission machines for low speeds and large loads. It is possible, however, to use chain in high speed environments. Chain is more suitable for long term continuous running.

Features of Chain Drives:

  • Speed reduction or increase of up to seven to one can be accommodated.
  • Chain can manage long shaft center distances and is more versatile.
  • It is possible to use chain with multiple shafts or drives using both sides of the chain.
  • Standardization of chains allow ease of selection.
  • Chain is easy to cut and connect.
  • The sprocket diameter for a chain set up may be smaller than a belt system while transmitting the same torque.
  • Sprockets are subject to less wear than gears because the load is spread over many teeth.
  • Chain needs to be lubricated.
  • Chain does wear and elongates.
  • Chain needs proper alignment.
  • Chain is weak if subjected to loads from the side.


To order chain, request a quote, or request information, please submit a Quote Request, and a Bearing & Transmission Supply representative will contact you. For immediate help, call us at 800-621-0237.