Features Reliable Performance: The milling tool holder has high thermal strength and oxygen resistance, as well as good comprehensive mechanical properties. Premium Metal Material: Using excellent 40CrMnTi material, surface quenching process, stable work and high hardness, no deformation after long term use. Double Sided Restraint Design: Bilateral card key, double sided restraint design, the milling tool holder is not easy to swing left and right during heavy cutting, ensures processing rigidity. Professional Made: The mill cutter tool holder has standard 7/16-20 thread, with high accuracy, easy installation and clamping and good work stability. For Milling Tool: The mill arbor adapter is commonly used in milling machine brackets, suitable for various CNC milling processes situations. Specification: Item Type: Milling Tool Holder Model: R8 FMB32 Material: 40CrMnTi Accuracy: 0.005mm Hardness: >HRC50°-55° Thread Size: 7/16-20 Package List: 1 x Milling Tool Holder Package List 1 x Milling Tool Holder