The Robert Charles Plain Shank Counterbore is a high-performance cutting tool designed for precision metalworking. Crafted from M35 HSS-E with 5% cobalt, it delivers heat resistance and durable cutting for consistent counterboring in demanding shops.

• Material: M35 HSS-E with 5% cobalt for enhanced heat resistance, wear life, and sustained cutting performance.
• Shank Type: Plain shank for easy fitment in standard tool holders and stable, reliable machining.
• Pilot Size: 0.179" pilot to guide the counterbore accurately and start the hole consistently.
• Cap Screw Compatibility: Designed for #8 cap screws, ensuring proper seating and flush appearance in assemblies.
• Counterbore Geometry: Precision-cut edges and geometry that produce clean, square, perpendicular counterbores.
• Ideal Applications: Suitable for precision engineering, automotive work, and general workshop tasks requiring durable, repeatable counterboring results.

This counterbore delivers predictable performance across common metalwork tasks, helping machinists achieve clean holes and secure fasteners with minimal rework. The cobalt-enhanced steel maintains sharpness longer under heat, while the plain shank simplifies tool changes and setup in everyday machining workflows. Use with appropriate feeds, speeds, and cooling as part of a well-managed cutting process to maximize tool life and accuracy.