ISO 7380-1 button head with hex drive, 08.8 M5 x 16, Article number 7380805016. Property class / material: steel 8.8, surface finish plain. Button Head with Hex Drive manufactured to ISO 7380-1 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.