The Robert Charles Plain Shank Counterbore is a high-performance cutting tool built for precision counterboring in metalworking. Designed for machinists, engineers, and automotive and workshop teams, it delivers reliable performance with clean, repeatable results.

• Material and alloy: M35-HSS-E with 5% cobalt for superior heat resistance, wear life, and cutting performance.
• Plain shank: Simple, standard shank design for easy fitment in common tool holders and stable machining.
• Counterbore geometry: Precisely engineered profile to produce accurate, smooth counterbores with consistent depth control.
• Size and pilot: 1/4 cap screw size with a 0.25 inch pilot to initiate cutting precisely where you need it.
• Applications: Ideal for precision engineering, automotive work, and general workshop tasks requiring durable, dependable counterboring.

This counterbore delivers steady performance under demanding workloads, helping you achieve accurate hole depths and clean finishes with fewer reworks. The cobalt-enhanced HSS keeps its edge longer in heat-intensive cuts, extending tool life and reducing downtime. The plain shank simplifies setup and minimizes runout, supporting reliable, repeatable results across multiple jobs.