high 20CrMnTi material, high hardness, wear resistance. Widely used for clamping , 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 surface and no harm to your hand operation. Specification: Product Model: Tool Holder Model: BT30-ER32-70 Use: 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 are not included. Note: Light reflection and different displays may cause the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.