... screw with all kinds of head and sizes finish:nickel plated,zinc plated with or without hardend self tapping screw with all kinds of head and sizesfasterner ... ,screws,1.finish:nickel plated,zinc plated,2. with or without hardend3. head ... ,M16,M18,M20,M22,M24,M27,M30 self tapping screw with all kinds of head and sizes