Our A Series Roller Chain meet or exceed DIN, ANSI,ISO,BS, ... toughest working environment. Our A Series Roller Chain meet or exceed DIN, ANSI,ISO,BS,JS standard, ... future.General Standard for Roller Chain:ROLLERSolid RollerMaterial 1035,1045 or 1050Through harden with surface and ... specCASE HARDENED PINMaterial 10B21 fine grain, 4118 or 8620Case harden(Carburized) 89HR 15MinimumHardness total case ...