... Hollow Bolt,Stainless Steel Hollow Bolt,Bolt with Internal Thread.1.What’s the specification of ... head,Countersunk head,Bugle head,Oval head,Hex flange head,Round head,Ball head,Button head... ... used in our products,Hexavalent chromium are accord with ROHS Standard. Weight Packing for each carton ... ,good technology1.We are a professional manufacturer with more than 20 years experiences in screw,bolt ...