DIN 7504-K hexagon head self-tapping screw with flange, ST5.5 x 38, Article number 7504K550381. Property class / material: steel, surface finish zinc plated. Hexagon Head Self-Tapping Screw with Flange manufactured to DIN 7504-K with ISO 1478 tapping screw thread (ST) 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.