1Made after fine workman, inner hole grinding, quenching and hardening, strong and durable 2Come with long service life, heat treatment with vacuum quenching furnace, improves the hardness of the tool holder 3Tool handle has a coating appearance, rustproof, wearresistant, and protect the spindle from wear 4Longterm thermal treatment, can effectively remove the residual internal stress during grinding 5Tool holder is used for CNC machine tool processing, speed 12000RPM, very practical Item Type: CNC Milling Tool Holder Model: SK40-ER32-70 Material: 20CrMnTi Hardness: 582HRC Purpose: Used for CNC machining Scope of Application: CNC machine tools Accuracy0.05mm Speed 12000RPM Clamping Range: Approx. 3 ~ 20mm / 0.1 ~ 0.8in L: Approx. 132mm / 5.2in D: Approx. 63mm / 2.5in d1 Nut Outer Diameter: Approx. 50mm / 2in 1 x CNC Milling Tool HolderPlease note that the new type and old type of this product will be sent randomly, and make sure you will not mind before ordering.