Washer head self‑drilling screw integrates a built‑in washer under the screw head. Its sharp drill tip can drill, tap and fasten in one step without pre‑drilled holes. The integrated washer enlarges contact area and distributes pressure. Material: carbon steel, stainless steel 304 / 316. Finishes: blue‑white zinc plated, color zinc plated, natural passivation. Widely used for metal sheet, roof panels, steel structure and building decoration.