Cleveland C91695 Solid Pilot Counterbore 0.23 in 3 Flute Hss

Product Description

The CLEVELAND C91695 is a solid pilot counterbore designed for precision counter-boring operations in ferrous and alloy materials. It features a 0.23-inch cutting diameter, a 0.135-inch standard pilot diameter, and three flutes for efficient chip evacuation. Constructed from high-speed steel (HSS) with a bright, uncoated finish, it delivers reliable performance in alloy tool steel, carbon steel, and cast iron. The straight-cylindrical shank measures 7/32 inch in diameter, and the tool runs 3 inches in overall length. It is compatible with Number 6 socket-head cap screws, making it a go-to tool for machinists and maintenance technicians who need clean, accurately sized counterbores for cap screw seating.

This counterbore is suited for general metalworking and MRO applications where Number 6 socket-head cap screws must seat flush or below a workpiece surface. Typical installations include machine frames, fixtures, tooling plates, and fabricated steel assemblies. The forward-cutting, three-flute geometry is well-matched to drill press, milling machine, and CNC operations on carbon steel and cast iron workpieces. The standard pilot ensures the counterbore tracks the existing clearance hole without requiring a separate pilot bushing.

Key Features

• 0.23-inch counterbore diameter sized for Number 6 socket-head cap screws
• 0.135-inch standard pilot diameter for positive hole registration
• Three-flute design promotes smooth cutting and chip removal
• High-speed steel construction handles alloy tool steel, carbon steel, and cast iron
• Bright uncoated finish — suitable for use with cutting fluid in standard shop conditions
• Straight-cylindrical 7/32-inch shank fits standard drill chucks and collets

Compatibility

Designed for use with Number 6 socket-head cap screws. Compatible material applications include alloy tool steel, carbon steel, and cast iron as specified by the manufacturer.

Installation Notes

A licensed machinist or qualified maintenance technician should install and operate this tool. Secure the workpiece firmly before operation and run the counterbore at a speed appropriate for HSS tooling in the workpiece material. Apply a suitable cutting fluid to extend tool life and improve surface finish. Inspect the pilot for wear before each use — a worn pilot can cause counterbore runout and an oversized seat.