Roller chain

In a roller chain adapted to have a load applied longitudinally thereto during its use comprising an assembly of apertured links, bushings which during use have a loaded side and an opposite unloaded side, rollers surrounding the bushings, pins connecting said links and passing through said bushings, said bushings being press fitted at both ends into transversely spaced pairs of alternate sets of links, and said bushings being formed from finite lengths of strip material and having a seam with the seam of being orientated to face one another, the improvement which comprises:

• providing at least one longitudinal groove in each pin terminating short of the ends thereof and within the bushing, said at least one groove being orientated to face the seam of the bushing through which it passes and orientated away from the direction of the load on the chain during use.