Precision machine and ground. Heavy duty and high quality material. OD Turning Tool Holder Brother Industries CNC Lathe Bolt-On Block Bundle. Measurements are posted in the pictures. Please feel free to reach out with any questions you may have. I will do my best to answer your questions and can provide more pictures if need be. Priced low to sell fast. I have so much that I can’t keep up with posting it. Thank you for your interest and support.