Feature:1. FOR LATHE OR MILL: Collet chuck can be mounted to a backing plate of your choice for use on a lathe or as a fixture on a mill2. OXIDATION RESISTANT CARBON STEEL: Made of excellent carbon steel material with black surface treatment, come with strong oxidation resistance, high hardness and long service life3. EASY SWITCHING: Threaded chuck allows for quick and easy installation and removal, saving your time when switching between applications4. HIGH ACCURACY WITHOUT LOOSENING: The flange adopts a seven hole structure, which can firmly lock your milling machine during use, not easy to loosen, and has higher operation accuracy5. FOR CNC MACHINES: Collet diameter is 100mm, used for CNC milling tools, and lathe, useful and practicalSpecification:Item Type: Collet ChuckModel: ER50 D100 (seven holes)Material: Carbon steelDiameter: Approx. 100mm / 3.94inAccuracy: 0.005.Package List:1 x Collet Chuck