Features Material 40CrMnTi: The cutter shank has high thermal resistance and oxidation resistance, as well as good integral mechanical properties, fully carbureted heat treatment for inner and outer diameter grinding, strong wear resistance and stable. High Accuracy - The accuracy of this milling head is up to 0.01mm, which can perfectly complete the tasks you need to complete. Main Application: The tool used by CNC milling machine can be connected to the spindle through the tool holder, and the speed and torque are transmitted by the tool holder, and the milling cutter is rotated to achieve the purpose of milling the work. Cooling Process: The cooling process on the surface of the cutter shank increases the hardness of the object and will not deform after prolonged use. Not easy to sway - the cutter handle has a double-sided card key and a double-sided restriction. It is not easy to turn left and right during heavy cutting to ensure rigidity of processing. Specification: Item Type: Shell Mill Spindle Adapter Material: 40CrMnTi Model No.: R8 FMB40 Accuracy: 0.01 mm Hardness: >HRC50°-55°3 Thread Size: 7/16-20 Package List: 1 x Shell Mill Tree Adapter Package List 1 x Shell Mill Arbor Adapter