Value Collection GH8815318 Counterbore 31/64 in Cobalt

Product Description

The VALUE COLLECTION GH8815318 is a cobalt steel interchangeable pilot counterbore designed for precision recess cutting in metalworking and machining applications. With a 31/64-inch counterbore diameter and a 7/16-inch straight shank, this tool delivers consistent, accurate counterbores in ferrous and hard materials where standard high-speed steel tooling falls short. The 3-flute geometry promotes chip clearance and smooth cutting action. Overall length is 4-5/16 inches, with a shank length of 3-1/16 inches. The bright, uncoated finish indicates the cobalt composition without any additional coating, keeping tool prep simple for the machinist.

This counterbore is suited for job shop, production machining, and maintenance environments where operators need to create recesses for socket head cap screws, bolts, or similar fastener heads. The interchangeable pilot design allows the pilot diameter to be swapped to match the fastener clearance hole, making this a versatile addition to a machining setup. It accommodates a 3/16-inch pilot shank diameter. Right-hand cutting direction is standard for conventional drill press and milling machine use.

Key Features

• Cobalt steel construction for improved heat and wear resistance compared to standard HSS
• 31/64-inch counterbore diameter for precise fastener head recesses
• 3-flute design promotes efficient chip evacuation during cutting
• Interchangeable pilot accepts 3/16-inch pilot shank diameter
• Straight 7/16-inch shank for secure chuck or collet holding
• Bright, uncoated finish — no pre-treatment required before use

Compatibility

Designed as a standard interchangeable pilot counterbore for use in drill presses, milling machines, and similar machine tool setups requiring a 7/16-inch straight shank and 3/16-inch pilot shank diameter compatibility.

Installation Notes

This tool is intended for use by machinists and toolroom professionals in machine tool applications. Secure the straight shank firmly in a drill chuck or collet before operation and confirm the correct pilot is installed for the clearance hole diameter in use. Power down the machine completely before changing pilots or removing the tool. Do not exceed the recommended spindle speed for the workpiece material and tool diameter.