Our Precision roller chain meet or exceed DIN, ANSI,ISO,BS,JS standard, ... stand up to the toughest working environment. Our Precision roller chain meet or exceed DIN, ANSI,ISO,BS,JS standard, ... with you in the near future.General Standard for Roller Chain:ROLLERSolid RollerMaterial 1035,1045 or 1050Through harden with surface ... 45HRCShot peening per the spec Duplex B Series 12B Precision Metal Chain