... Bolt,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 ... demand .Threads/ScrowsType "M","UNC","UNF","BSW"thread are available. Head typesHexagon head,Mushroom head,Pan ... more than 20 years experiences in screw,bolt,nut,washer,rivet, stud, pin,wrench and so on .2. ...