The Robert Charles Plain Shank Counterbore – Standard Metric (M4) is a precision cutting tool designed for accurate counterboring in metalworking and manufacturing. It features a plain shank for compatibility with standard tool holders, delivering reliable, repeatable results in metric hole applications.

• Plain shank design: Compatible with standard tool holders for quick setup and stable alignment.
• Metric size: Standard metric M4 configuration tailored to metric hole standards.
• Clean, precise counterboring: Geometry engineered to produce flat-bottom holes with smooth walls for accurate fastener seating.
• Reliable performance: Built for repeatability in demanding workshop environments.
• Versatile applications: Suitable for general engineering, automotive, and workshop tasks requiring precision and consistency.

Using this counterbore helps achieve well-defined counterbored features that improve nut and bolt seating, torque transfer, and joint integrity. The plain shank simplifies tooling setup and reduces runout, contributing to tighter tolerances and more consistent results across multiple parts. Ideal for technicians and hobbyists who value reliability and accuracy in metric hole standards.