ISO 4017 hexagon head screw, M12 x 20, sst 72 h, Article number 40178120201SST072. Property class / material: steel 8.8, surface finish zinc plated. Hexagon Head Screw manufactured to ISO 4017 with ISO metric (M) thread, coarse pitch, fully threaded. Standard parts to the same standard, property class, dimensions and surface finish are interchangeable between manufacturers; confirm the controlling standard revision, any class-society or application approval, and the mating thread before substitution.