The Robert Charles Plain Shank Counterbore is a durable, high-precision tool designed for clean, repeatable counterboring in metalwork. Built for engineers, machinists, and shops that demand consistent results, it delivers reliable performance in demanding materials and applications.

• Material: M35-HSS-E with 5% cobalt for superior heat resistance and wear life.
• Shank Type: Plain shank for easy fitment in standard tool holders, ensuring stable machining.
• Size & Pilot: #10 cap screw size counterbore with a 0.221" pilot to promote accurate hole alignment.
• Cutting Geometry: Optimized design for clean counterbores with a flat bottom and consistent depth.
• Applications: Ideal for precision engineering, automotive work, and general workshop counterboring tasks requiring durability.

Experience longer tool life and reliable performance even in demanding materials thanks to the cobalt-enhanced M35 steel. The plain shank simplifies changes and setup, while the precise 0.221" pilot guides the cutter for repeatable countersinks. Use this counterbore to achieve consistent, flush-bottom recesses on every part, reducing rework and improving part quality in both production runs and prototyping.