This spur gear shaft used in construction machinery . Gear shafts in transmission machinery are usually made of 45 steel in high-quality carbon steel, 40Cr, 20CrMnTi in alloy steel, etc. Generally, it meets the strength requirements of the material, and the wear resistance is good. This spur gear shaft was made by 20MnCr5 low carbon alloy steel ,carburizing into 58-62HRC.