high quality 20CrMnTi material, high hardness, wear resistance. Widely used for clamping cutters, drills, reamers and other cutting tools. Speed: 25000 rpm carburizing and quenching process to make the handle withstand certain impact and load, strong toughness, super clamping force, no looseness, no deformation, exquisite craftsmanship bring smooth and no harm to your hand operation., Manufacturer: Aundhegrtt