Keo 902-000-056 Solid Pilot Counterbore 11mm 3 Flutes

Product Description

The KEO 902-000-056 is a solid pilot counterbore designed to produce clean, flat-bottomed counterbore seats for socket-head cap screws in metalworking and machining applications. Built from cobalt steel with a bright, uncoated finish, it delivers strong wear resistance and heat tolerance during cutting. The tool features a 11 mm counterbore diameter, a 6.4 mm pilot diameter for precise hole alignment, and 3 flutes for efficient chip evacuation. With an 8 mm shank diameter and an overall length of 80 mm, it fits standard drill press and milling machine setups used by machinists and toolroom professionals.

This counterbore is suited for creating recessed seating for 6 mm socket-head cap screws in ferrous metals, alloy steels, and other materials where cobalt steel tooling is appropriate. It is used in production machining, maintenance and repair operations, and toolroom work where accurate counterbore depth and concentricity are required. The standard pilot ensures proper alignment with a pre-drilled clearance hole, making it a reliable choice for repetitive fastener seating operations on manual mills, drill presses, and CNC equipment.

Key Features

• 11 mm counterbore diameter seats 6 mm socket-head cap screws flush or below workpiece surface
• 6.4 mm standard pilot diameter aligns tool concentrically with pre-drilled clearance hole
• 3-flute geometry promotes efficient chip removal and smooth cutting action
• Cobalt steel construction provides elevated heat and wear resistance compared to standard high-speed steel
• Bright, uncoated finish for straightforward resharpening in the field
• 8 mm shank diameter fits common drill chuck and collet setups

Compatibility

Designed for use with 6 mm socket-head cap screws. Compatible with standard pilot counterbore applications requiring an 11 mm counterbore diameter and a 6.4 mm pilot. Fastener type compatibility is socket-head cap screw per manufacturer specifications.

Installation Notes

Installation of this counterbore is performed by machinists using a drill press, manual milling machine, or CNC machining center. Always ensure the workpiece is securely clamped and the spindle speed is appropriate for the material being cut and the tool diameter before beginning operation. The pilot must engage a pre-drilled clearance hole that matches the pilot diameter to maintain concentricity. Inspect the pilot for wear or damage before each use, and avoid forcing the tool into the workpiece to prevent pilot breakage or chatter.