... ,Stainless Steel Hollow Bolt,Bolt with Internal Thread.1.What’s the specification of our Products ? MaterialsCarbon steel,Stainless steel,Alloy steel,Copper,Aluminum are available.Carton steel ... ,Bugle head,Oval head,Hex flange head,Round head,Ball head,Button head... Socket typesPhillip type,Pozi type,Eleven ... to call me any time !Tel:+86-15917002605 Stainless Steel Hollow Bolt With Internal Thread