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