The Robert Charles Plain Shank Counterbore is a durable, precision cutting tool designed for clean, accurate counterbores in metalwork. Built for engineers, machinists, and workshop professionals, it delivers reliable performance from start to finish with a cobalt-enhanced edge for tough jobs.

• Material: M35-HSS-E with 5% cobalt for excellent heat resistance and edge retention during high-speed machining.
• Shank Style: Plain shank for quick, stable fitment in standard tool holders, enabling smooth setup and repeatable results.
• Pilot Size: 0.112" pilot to guide the countersink and help maintain accurate depth control.
• Cap Screw Compatibility: Sized for #4 cap screws, ensuring reliable seating and flush installation in common assemblies.
• Finish: Bright, polished body that resists wear and simplifies cleanup between jobs.

In practice, this counterbore delivers square, true counters with minimal runout, reducing rework and improving fastener seating across a range of metals. The high-performance cobalt-enhanced steel holds a sharp edge longer, meaning fewer tool changes in production or repair work. The plain shank and precise 0.112" pilot make it a dependable choice for precision engineering, automotive components, and general workshop applications where durability and consistent results matter.