... ,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, Zinc-Plating or according ...