Our A Series Roller Chain meet or exceed DIN, ANSI,ISO,BS,JS ... and stand up to the toughest working environment. Our A Series Roller Chain meet or exceed DIN, ANSI,ISO,BS,JS ... 15MinimumHardness total case depth per the specCASE HARDENED PINMaterial 10B21 fine grain, 4118 or 8620Case harden(Carburized) 89HR 15MinimumHardness total ... core 39-45HRCShot peening per the spec 5-Strands A Series Roller Chain