... 8 ,6.8,8.8,9.8.... Copper Bolts,Copper Bolt,Brass Bolts.1.What’s the specification ... Products ? MaterialsCarbon steel,Stainless steel,Alloy steel,Copper,Aluminum are available.Carton steel is high quality ... A 40GP will be 40T-52T.additioal processes Washer assembly,Heat treatment,Baking hydrogen,Anti-slipping ... more than 20 years experiences in screw,bolt,nut,washer,rivet, stud, pin,wrench and so on ...