Standard: DIN 912 / ASME B18.3
mm diameter: up to M36 Strength: CLS 12.9
Inch diameter: up to 1 ” Strength: Gr. 8
Generally supplied black without coating
Coatings and protective layers: Zinc – white, black, yellow.
Zinc iron – colored, white, black Zinc nickel – white, black
See also Allen screw with stainless steel head