... ,Worm,Spiral or other types 5) Use application: gear box for steelworks Product TypeCNC hobbing gearMaterial:42CrMo, 20CrMnMo, 20Cr2Ni4, 35CrMo, 20CrMnTi ... ,17CrNi2MoA and other high intensity alloy steelProcess methodCNC Turning, milling ,hobbing,drilling, grinding,plating etc.Surface finish:Chrome plating ...