Hollow Bolt,Stainless 1.ISO,ANSI,CE,JIS,DIN,BS& non- ... :4.8 ,6.8,8.8,9.8..... Hollow Bolt,Stainless Steel Hollow Bolt,Bolt with Internal Thread.1.What’s the ... ,Combined type... FinishZinc plated,Nickel plated,Dacroment Plated,chromium plated,Tin plated,Black phosphating ,anodized ,Parkerising,and Environmental Plated is used ...