Keo 902-000-040 Cobalt Counterbore Set 7 Piece

Product Description

The KEO 902-000-040 is a 7-piece cobalt steel counterbore set designed for use with socket head cap screws. Each cutter features a solid standard pilot, straight cylindrical shank, and 3 flutes ground for forward cutting. Cobalt steel construction provides increased heat and wear resistance compared to standard high-speed steel, making this set appropriate for harder workpiece materials and higher-production drilling environments. The set covers fractional fastener sizes from 1/4 inch through 1/2 inch and arrives in a plastic storage case. The set weighs 1.9 pounds.

This counterbore set is used to create flat-bottomed recesses that allow socket head cap screw heads to sit flush with or below a workpiece surface. It is suited for machine shops, maintenance facilities, and fabrication environments where socket head cap screws in the 1/4 inch, 5/16 inch, 3/8 inch, and 1/2 inch range are commonly installed. The straight shank design accommodates standard drill press and milling machine chucks. The plastic storage case keeps cutters organized and protected between uses.

Key Features

• Cobalt steel construction for improved heat resistance and tool life in harder materials
• Standard solid pilot for accurate bore alignment over existing clearance holes
• 3-flute geometry for forward cutting with efficient chip evacuation
• Straight cylindrical shank for compatibility with standard chucks and collets
• Covers four fractional sizes: 1/4 inch, 5/16 inch, 3/8 inch, and 1/2 inch socket head cap screws
• Bright finish; 7-piece set stored in a plastic case

Compatibility

Designed for use with socket head cap screws ranging from No. 10 wire size through 1/2 inch fractional size, covering 1/4 inch, 5/16 inch, 3/8 inch, and 1/2 inch fastener sizes.

Installation Notes

Counterbore operations are typically performed by machinists or maintenance technicians using a drill press, milling machine, or hand-held power drill with a stable fixture. Power down and de-energize all equipment before changing or setting cutters. Use appropriate cutting fluid for the workpiece material to extend tool life and improve finish quality. Secure the workpiece firmly before starting the cut to prevent movement that could damage the pilot or cutter.