Features 1、Via hardened treatment, the chuck holder is durable to use, which is also suitable for inner hole milling cutter. 2、Given that such collet chuck tool holder supports wide application, it is also suitable for various machine tools. 3、Lathe tool holder is with high hardness for long life, after quenching and hardening. 4、Made of high speed steel, chuck holder is not easy to damage, and you can use for a long time. 5、Built to strict quality control standards, the milling tool holder's design is improved for more durability. Specification Item Type: CNC tool holder Material: High speed steel Applicable Machine: Milling machine Hardness: Approx. 55 ~ 58 Accuracy: Within 0.003mm Clamping Range: Approx. 1 ~ 20mm / 0.04 ~ 0.79in Speed: 30000 rpm Whether Coated: Non-coated Shank Diameter: Approx. 20mm / 0.8in FMB Guide Post: Approx. 27mm / 1.1in Applicable Cutter Diameter: Approx. 80mm / 3.1in Package List 1 x CNC Tool Holder