Value Collection GH8790404 Counterbore 5/8 in Hss 3 Flute

Product Description

The Value Collection GH8790404 is a straight-shank interchangeable pilot counterbore designed for creating accurate counterbored holes in metal workpieces. Machined from high speed steel with a bright, uncoated finish, this tool features a 5/8 inch cutting diameter and a 1/2 inch straight shank. Three right-hand flutes provide efficient chip evacuation during cutting. The interchangeable pilot design accepts a 3/16 inch pilot shank, allowing the counterbore to be used with separately sourced pilots for precise hole location and concentricity control. Overall length is 5-1/8 inches with a shank length of 3-7/8 inches.

This counterbore is suited for use in machine shop, maintenance, and metalworking environments where bolt-head or fastener seating requires a flat-bottomed recess. It is compatible with standard drill presses, knee mills, and machining centers equipped with a 1/2 inch toolholder or collet chuck. Typical applications include producing counterbores for socket head cap screws and similar fasteners in ferrous and non-ferrous metals. This tool is intended for professional machinists, tool and die makers, and maintenance technicians working in production or job-shop settings.

Key Features

• 5/8 inch counterbore diameter for standard fastener seating applications
• High speed steel construction provides good wear resistance across ferrous and non-ferrous materials
• Three right-hand flutes for efficient chip removal and smooth finish
• Interchangeable pilot accepts 3/16 inch pilot shank for accurate hole location
• Bright uncoated finish suitable for general-purpose machining
• Straight 1/2 inch shank for compatibility with standard collets and toolholders

Compatibility

Designed as a standard interchangeable pilot counterbore compatible with 1/2 inch straight-shank toolholders and collet chucks; accepts a 3/16 inch diameter pilot shank.

Installation Notes

This tool is installed and operated by machinists and metalworking technicians using drill presses, mills, or machining centers. Secure the shank firmly in a 1/2 inch collet or toolholder before operation and verify the pilot is properly seated before beginning the cut. Ensure the workpiece is clamped securely to prevent movement during counterboring. Use appropriate cutting fluid for the workpiece material to extend tool life and improve surface finish.