... ..... Hollow Bolt,Stainless Steel Hollow Bolt,Bolt with Internal Thread.1.What’s the specification of ... plated,Nickel plated,Dacroment Plated,chromium plated,Tin plated,Black phosphating ,anodized ,Parkerising,and Environmental Plated is used in our products,Hexavalent chromium are accord with ... ,good technology1.We are a professional manufacturer with more than 20 years experiences in screw,bolt ...