ISO 14581 flat head screw with torx, 08.8 M4 x 18, Article number 14581804018. Property class / material: steel 8.8, surface finish plain. Flat Head Screw with Torx manufactured to ISO 14581 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.