These holes, located on the inner side of the bushings away from bearing area, function as a reservoir for extra lubricant. This feature reduces chain wear and extend the chain’s operating life.

OCM's repunching process removes the taper

of hole. Both sides of the hole are parallel, better

bearing between pins and holes. 

This process increases fatigue strength

Cylindrical Roundness - Solid Bushings

The advantage of solid bush, cylindrical roundness, makes for a large bearing area and oil port as an oil reservoir, improves the chain wear resistance and minimize chain elongation.

OCM roller chain is preloaded automatically after 

assembly to minimize initial elongation