The Robert Charles Plain Shank Counterbore is a high-performance tool engineered for precise, repeatable counterboring in metalworking. Designed for machinists, engineers, and workshop professionals, it pairs durability with straightforward integration into standard tool holders.

• Material: M35-HSS-E with 5% cobalt for improved heat resistance, wear life, and cutting performance at higher speeds.
• Shank Type: Plain shank for easy clamping in conventional tool holders, delivering stable and reliable machining.
• Counterbore Size: 7/8 inch counterbore diameter compatible with standard cap screws and flush seating.
• Pilot Size: 0.891 inch pilot provides precise start and accurate hole centering for clean counterbores.
• Geometry: Optimized flute design and relief to promote efficient chip evacuation and minimal chatter.
• Applications: Ideal for precision engineering, automotive assembly, and general workshop tasks requiring durable, consistent counterboring results.

This counterbore delivers consistent, repeatable results across workpieces, helping you achieve flush-cap screw seating with minimal rework. The cobalt-enhanced HSS composition maintains cutting efficiency during extended machining cycles, while the plain shank simplifies setup and reduces tool-change time. Built for reliability in demanding environments, it’s a practical choice for shops that value accuracy, durability, and steady performance.