... ,9.8.... Copper Bolts,Copper Bolt,Brass Bolts.1.What’s the specification of our Products ? MaterialsCarbon steel,Stainless ... Tin plated,Black phosphating ,anodized ,Parkerising,and Environmental Plated is used in our products,Hexavalent chromium are accord with ROHS Standard. ... ,have some special persons in charge of quality control.we random check or total check products in each procedure,products will ...