alloy round bar standard:Chinese GB,ASTM, DIN Material: ... 400mm length:6m or more for industry alloy steel round barstandard:Chinese GB,ASTM, DINMaterial:42CrMo,42CrMo4,4040diameter:12 ... , connecting rod, transmission gear, supercharger gear, engine cylinder, spring, 1200mm~2000mm rotary shouldered connections for petroleum industry, jar knocker ... larger size than 35CrMo. 42CrMo alloy steel round bar