... , Length: 25-50mm Surface treatment:Phosphating Self tapping screw1.various kinds of self tapping screws are available.2.high quality,competive ... steel,alloy steel,copper etc.4.surface treatment of self tapping screw: Phosphating passivation,Zinc-Plating or according client's ... spec according to client's requirement.6.packing of self tapping screw:export packing cartons or according client's ...