Butterfly screws. 1)Standard :DIN316 (American Form) 2)Size:M3 to M12, 1/4 to 1/2" 3)Material :mild steel,SUS304 Feature:1) Standard of butterfly screws: DIN316 (American Form)2) Size: M3 to M12, 1/4 to 1/2"3) Material: mild steel, SUS304Outer packing: Carton or poly bag + PalletOur company supply butterfly screw. Butterfly Screws