DIN 6921-Z hexagon head screw with flange (form Z), M8 x 20, sst 400 h, serrated, Article number 6921Z8080201SST400. Property class / material: steel 8.8, surface finish zinc plated. Hexagon Head Screw with Flange manufactured to DIN 6921 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.