The Robert Charles Plain Shank Counterbore is a precision cutting tool designed for engineers, machinists, and workshops that demand clean, accurate counterbores and dependable performance. Crafted from M35-HSS-E with 5% cobalt, it combines heat resistance with durable wear life, while the plain shank ensures straightforward mounting in standard tool holders.

• Material and Grade: M35-HSS-E with 5% cobalt for enhanced heat resistance and extended wear life in demanding cutting conditions.
• Shank Type: Plain shank design for easy fitment into standard tool holders and stable, reliable machining.
• Counterbore Size and Pilot: Engineered for a 3/4 cap screw size with a 0.766 inch pilot to ensure precise alignment through the workpiece.
• Cutting Geometry: Optimized edge and flute geometry to produce clean, flat-bottom counterbores with smooth chip evacuation.
• Precision and Tolerances: Manufactured to tight tolerances to deliver repeatable depths and consistent results across jobs.
• Application Fit: Ideal for precision engineering, automotive assemblies, and general workshop machining where durable, repeatable counterboring is essential.

This counterbore helps you achieve flush-cap screw seating with minimal burrs, boosting joint strength and finish quality. The cobalt-enhanced alloy maintains hardness under higher cutting speeds, reducing tool wear and downtime. With its straightforward plain-shank design, it integrates seamlessly into existing setups, while the 0.766 inch pilot ensures accurate guidance through the workpiece for reliable, repeatable performance.