alloy round bar standard:Chinese GB,ASTM, DIN Material:a42CrMo,42CrMo4,4040 ... :12-400mm length:6m or more for industry alloy steel round barstandard:Chinese GB,ASTM, DINMaterial:42CrMo,42CrMo4,4040diameter:12-400mm ... is often applied for making important machinery parts, such as bearing, gear, connecting rod, transmission gear, supercharger gear, engine cylinder, spring ...