high quality 20CrMnTi material, high hardness, wear resistance. Widely used for clamping , drills, reamers and other cutting . 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 surface and no harm to your hand operation. Specification: Product : Tool Holder : BT30-ER32-70 : machining Working length of tool post: about 70mm Nut diameter: about 50mm Spindle taper: 7/24 Speed: 25000U/min Main body accuracy: 0.002-0.005mm Coaxiality: less than 0.005mm Overall clamping accuracy: 0.002-0.005mm Hardness: 52-58HRC Colour: Silver Material: 20CrMnTi Package Contents: 1 x BT30-ER32-70 Milling Tool Holder Only the above package content, other products are not included. Note: Light reflection and different displays may the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.