The Robert Charles Plain Shank Counterbore is a high-performance cutting tool crafted from M35 HSS‑E with 5% cobalt, built for precise, clean counterboring. Ideal for precision engineers, automotive shops, and general workshop use, it delivers durable performance and repeatable results in demanding materials.

• Material and Grade: M35 HSS‑E with 5% cobalt for enhanced heat resistance, wear life, and cutting performance.
• Shank Design: Plain shank for easy fitment in standard tool holders, ensuring stable machining.
• Counterbore Geometry: Optimized profile for accurate depth control and clean, flat-bottom holes.
• Pilot Size: 0.5 pilot size provides reliable hole alignment and consistent starting point.
• Cap Screw Size: 1/2" cap screw compatibility for secure seating in common fixtures.
• Applications: Suited to precision engineering, automotive work, and general workshop tasks requiring durability and repeatability.

This counterbore delivers reliable, repeatable holes with crisp edges and reduced need for rework. The plain shank simplifies tool changes across machines and standard tool holders, helping you save setup time. The cobalt-enhanced HSS profile maintains sharpness and dimensional accuracy during extended cuts, making it suitable for projects such as precision fixtures, mounting plates, and fastener chambers where a true, flat-bottom counterbore matters most.