... 6.3mm 4.Finish:zinc plated Hexagon washer head self drilling screw with tapping screws thread Standard:DIN 7504, ANSI/ASME B18 ... .64, Hex washers self drilling screw,Washer Head Self-Drilling Screw ... ,Pan Framing,drywall screw of self drilling screw), Hex Head self drilling screwSpecial ...