self drilling screw 1.feature:hex head,drill-shaped point. 2.material:carbonsteel 3.finished:zinc coated 1.Standard of Sheet Metal Fabrication : DIN 933/931 ... /912,DIN 960/961,IS0 4014/4017,ANSI/ASME B18.2.1 IFI A101)Standard of Sheet Metal Fabrication : DIN95/96/97 ... )Material of Sheet Metal Fabrication : 6A,8A,brass,stainless steel and so on.4)Surface of Sheet Metal Fabrication : plain, zinc ...