1.high cost performance screw 2.size of the screw:M1.6-M9.5 3.surface of screw:zp,hdg,black,oxide 4.rohs iso certification flat head self tapping screw1.various kinds of self tapping screw available.2.high quality competive price .3.material of the self tapping screw:stainless steel ,carbon steel,alloy steel,copper etc...4.surface treatment of self tapping screw:Passivation,Chromium-Plating,Black ...