Cleveland C91723 Solid Pilot Counterbore 25/32 in 3 Flutes Hss

Product Description

The CLEVELAND C91723 is a solid pilot counterbore designed for precision spot-facing and counterboring operations in metal fabrication and machining applications. Built from high-speed steel (HSS) with a bright, uncoated finish, this tool delivers clean, accurate seats for socket-head cap screws in production and maintenance environments. It features a 25/32-inch counterbore diameter, a 17/32-inch standard pilot diameter, and three flutes for efficient chip evacuation and smooth cutting action. The straight-cylindrical shank measures 1/2 inch in diameter, and the overall length is 7.25 inches, making it suitable for both benchtop and floor-standing drill press setups. Machinists, tool-and-die workers, and maintenance technicians are the primary installers of this type of tooling.

This counterbore is sized specifically for 1/2-inch socket-head cap screws, providing the correct counterbore diameter and pilot combination for a standard, interference-free fit. It is well suited for use in alloy tool steel, carbon steel, and cast iron workpieces. Forward cutting direction makes it compatible with conventional right-hand drill press and milling machine spindles. It is commonly used in job shops, OEM production lines, and maintenance repair operations where consistent screw-seat geometry is required.

Key Features

• 25/32-inch counterbore diameter sized for 1/2-inch socket-head cap screws
• 17/32-inch standard pilot diameter for accurate hole alignment and concentricity
• 3-flute geometry promotes efficient chip removal and smooth cutting in ferrous materials
• High-speed steel construction handles alloy tool steel, carbon steel, and cast iron
• Bright, uncoated finish suitable for use with cutting fluids in standard machining environments
• 1/2-inch straight-cylindrical shank fits standard drill chucks and end mill holders
• 7.25-inch overall length provides reach for most standard workpiece thicknesses

Compatibility

Designed for use with 1/2-inch socket-head cap screws. Compatible with alloy tool steel, carbon steel, and cast iron workpieces. Fits standard drill press and milling machine spindles accepting a 1/2-inch straight shank.

Installation Notes

This tool is installed and operated by machinists or qualified maintenance technicians using a drill press, mill, or similar machine tool. Before mounting, ensure the machine spindle is fully stopped and the chuck or collet is clean and undamaged. Secure the straight shank firmly in the chuck or collet to the full depth of the shank to prevent pullout during cutting. Apply an appropriate cutting fluid for the workpiece material to extend tool life and improve surface finish quality.