... )2.Material: aluminum, mild steel, stainless steel, chrome steel, cold rolled sheet, bearing steel, brass, copper, ... bronze, chrome copper, mold steel , teflon ,PVC, bakelite, nylon, ... high frequency, anodizing, clear anodizing,black anodizing ,chrome plating, black oxide coating, nickel plating, zinc plating, nitriding, degreasing, painting and so on.4 ...