... , enamel, hot-dip, polishing, hardening clear anodizing, chrome plating, nickel plating, zinc plating, oil injection, black oxide coating and so onmaterialstainless steel ... , iron ( SPCC, SECC, SPTE, tinplate), aluminum alloy, red copper,brass, bronze finish Zinc/nickel/chrome plating, hot galvanized, painting, PVC powder coating ...