welding screw Material:Aluminum, stainless steel, iron,copper Size:M3-M20 Standard:GB,DIN,ISO,ANSI,JIS etc welding screw with high quality and competitive priceMaterial:Aluminum, stainless steel, iron,copperSize:M3-M20Standard:GB,DIN,ISO,ANSI,JIS etcwe also can according to the customers drawing to make FD welding screw