DIN-EN

1.6566 = 17CrNiMo6-4 and 1.6569 = 17CrNiMoS6-4는
DIN-EN 10084-2, Case Hardening Steels 규정을 따르고

1.6569 = 17NiCrMoS6-4는 DIN-EN 10084-2 and DIN-EN
10277-4 Bright Steel Products 규정, 2가지