1) Items: welded link chain/ weldless chain / knotted chain. 2) Material:carbon steel /alloy steel / stainless steel 3) St Link chain: 1.6mm-22mm chains 2.Material:20Mn2 or 25Mnv 4.Automatic production machines 5.Grade 80 welded link chains 1) Grade: G80, G70, G60, G43, G302) Surface treatment: Self color, blackened, painted, electro galvanized, hot dip galvanized, painted etc.3) Material: 20Mn2, ...