Keo 902-000-019 Solid Pilot Counterbore 0.475 in 3 Flutes

Product Description

The KEO 902-000-019 is a solid pilot counterbore designed for precision spot-facing and counterboring operations in metal fabrication and machining applications. It features a 0.475-inch counterbore diameter, a 0.312-inch standard pilot diameter, and three flutes for efficient material removal and chip evacuation. The tool is manufactured from cobalt steel, providing elevated heat and wear resistance compared to standard high-speed steel. With a straight-cylindrical shank diameter of 0.375 inches and a 4.5-inch overall length, this counterbore fits a broad range of milling machines, drill presses, and manual machining setups commonly used in shops and field maintenance environments.

This counterbore is sized for use with 5/16-inch socket-head cap screws, making it a go-to tool when preparing bolt seats in steel, aluminum, cast iron, and similar materials. It is suited for production machining, maintenance and repair operations, and prototype work where consistent counterbore depth and seat concentricity are required. The forward cutting direction and bright uncoated finish make it compatible with standard cutting fluid applications. Machinists, toolmakers, and maintenance technicians across manufacturing, aerospace support, and general metalworking will find this a reliable fit for repeat counterboring tasks.

Key Features

• 0.475-inch counterbore diameter sized for 5/16-inch socket-head cap screws
• 0.312-inch standard pilot diameter for accurate hole alignment and seat concentricity
• Three-flute geometry promotes efficient chip evacuation and clean seat finish
• Cobalt steel construction resists heat buildup during extended cutting cycles
• Straight-cylindrical shank at 0.375 inches diameter fits standard toolholders and drill chucks
• Bright uncoated finish compatible with water-soluble and oil-based cutting fluids

Compatibility

Designed for use with 5/16-inch socket-head cap screws. Fits toolholders and drill press chucks accepting a 0.375-inch straight-cylindrical shank.

Installation Notes

Install and remove this tool only with the machine powered down and locked out per applicable safety procedures. Secure the shank firmly in the toolholder or drill chuck before operation to prevent runout. Use appropriate cutting fluid for the workpiece material to extend tool life and maintain surface finish quality. This tool is intended for use by qualified machinists or maintenance technicians familiar with counterboring operations and machine tool safety practices.