Cleveland C91722 Solid Pilot Counterbore 49/64 in Hss

Product Description

The CLEVELAND C91722 is a solid pilot counterbore designed for precise counterboring operations on ferrous materials including alloy tool steel, carbon steel, and cast iron. The cutter features a 49/64 inch counterbore diameter paired with a 33/64 inch standard pilot diameter and three flutes for controlled chip evacuation and a clean, flat-bottomed seat. Built from high-speed steel with a bright, uncoated finish, this tool delivers reliable performance in manual and CNC machine applications. At 7.25 inches overall length with a straight-cylindrical 1/2 inch shank, it fits standard toolholders and drill press setups used by machinists and maintenance technicians alike.

This counterbore is sized specifically for 1/2 inch socket-head cap screw clearance applications. It is well suited for manufacturing, maintenance, and repair operations where a flat-bottomed recess is required to seat a cap screw flush with or below a work surface. Typical use cases include machine frame assembly, fixture fabrication, and structural component repair across industrial and production environments. The straight-cylindrical shank allows direct chucking without adapters in most standard drill press or milling machine setups.

Key Features

• 49/64 inch counterbore diameter sized for 1/2 inch socket-head cap screws
• 33/64 inch standard pilot diameter for accurate hole alignment and concentricity
• 3-flute geometry for efficient chip removal and smooth seat finish
• High-speed steel construction handles alloy tool steel, carbon steel, and cast iron
• Bright uncoated finish suitable for use with cutting fluid on a range of workpiece materials
• 1/2 inch straight-cylindrical shank fits standard chucks and toolholders without adapters

Compatibility

Designed for use with 1/2 inch socket-head cap screws. Compatible material applications include alloy tool steel, carbon steel, and cast iron. Standard pilot style — not aircraft style.

Installation Notes

This tool is installed by machinists and maintenance technicians in drill press or milling machine setups. Secure the straight-cylindrical shank firmly in a drill chuck or end mill holder before use, and verify pilot clearance in the existing hole before engaging the cutter. Apply appropriate cutting fluid for the workpiece material to extend tool life and improve surface finish. Always power down and lock out the machine spindle before changing or adjusting the counterbore.