... More than 20 years experience in special field Name: cylindrically coil spring Ability for the material of this kind of hanger: Grade3 ... .6,4.8,5.6,6.8,8.8,9.8,10.9,12.9,etcCarbon steelGr.B,Gr.C,Gr.D,Gr ... for exporting so that you couldavoid lots of risks. cylindrically coil spring