Keo 902-000-015 Solid Pilot Counterbore 0.346 in 3 Flute

Product Description

The KEO 902-000-015 is a solid pilot counterbore designed for precision seat cutting in metal fabrication and machine shop applications. Built from cobalt steel with a bright, uncoated finish, this tool delivers the hardness and heat resistance required for consistent performance in ferrous and harder materials. It features a 0.346-inch counterbore diameter, a 0.221-inch oversize pilot diameter, and three flutes for efficient chip evacuation and a clean, accurate bore seat. The straight-cylindrical shank measures 9/32 inch in diameter, providing secure tool holding in standard drill press or milling machine setups. Machinists and tool-and-die professionals rely on this style of counterbore for flush-seat preparation work.

This counterbore is sized for use with number 10 socket-head cap screws, making it well suited for tooling fixtures, machine components, and mechanical assemblies where cap screws must sit flush or below the workpiece surface. The oversize pilot ensures the tool tracks cleanly in a pre-drilled clearance hole, maintaining concentricity between the pilot bore and the counterbore seat. Its 4.5-inch overall length provides adequate reach for standard workpiece thicknesses encountered in general machining and production environments. The forward cutting direction is standard for right-hand drill press and mill spindle operation.

Key Features

• Cobalt steel construction for increased hardness and heat resistance compared to standard high-speed steel
• 0.346-inch counterbore diameter sized for number 10 socket-head cap screws
• 0.221-inch oversize pilot diameter maintains concentricity in pre-drilled holes
• Three-flute geometry promotes efficient chip clearance and smooth seat finish
• Straight-cylindrical 9/32-inch shank for secure chuck or collet holding
• Bright, uncoated finish suitable for general-purpose ferrous and non-ferrous machining

Compatibility

Designed for use with number 10 socket-head cap screws. Intended for workpieces with a pre-drilled clearance hole that accepts the 0.221-inch oversize pilot. Compatible with standard drill press chucks and milling machine collets sized for a 9/32-inch straight shank.

Installation Notes

This tool is installed and operated by machinists using a drill press, mill, or similar machine tool. Secure the straight shank firmly in a chuck or collet before operation and verify the spindle is fully stopped before making any tool changes or adjustments. Use appropriate cutting fluid for the workpiece material to extend tool life and improve finish quality. Always follow shop safety protocols and machine manufacturer guidelines when operating rotating cutting tools.