Value Collection GH8790594 Counterbore 59/64 in 3 Flute Hss

Product Description

The VALUE COLLECTION GH8790594 is a 3-flute interchangeable pilot counterbore designed for precision spot-facing and counterboring operations in metal fabrication and machining applications. Built from high speed steel with a bright, uncoated finish, this tool accepts a 1/4 inch pilot shank and features a 59/64 inch cutting diameter. The 3/4 inch straight shank seats securely in standard tool holders. Right-hand cutting geometry produces clean, flat-bottomed seats for fastener heads and bearing shoulders. The bright finish reduces friction during cutting and makes wear inspection straightforward. Machinists and toolroom technicians working on drill press, milling machine, or CNC setups will find this tool compatible with common straight-shank toolholding systems.

This counterbore is suited for production and maintenance machining where interchangeable pilots allow a single body to serve multiple hole sizes. Typical applications include creating recessed seats for socket head cap screws, hex bolts, and dowel pin bores in steel, aluminum, and similar machinable metals. The 6-1/8 inch overall length and 4-5/8 inch shank length provide reach for deeper setups or fixtures that require clearance from a spindle nose. Shops running low-volume job work or repair machining will find this tool a practical addition to a general counterbore set.

Key Features

• 59/64 inch counterbore cutting diameter for precise fastener seat sizing
• 3 flutes for smooth chip evacuation and balanced cutting action
• High speed steel construction provides good wear resistance across common work materials
• Straight 3/4 inch shank fits standard drill press and milling machine toolholders
• Interchangeable 1/4 inch pilot design allows pilot replacement without changing the body
• Bright, uncoated finish for easy inspection and reduced built-up edge on non-ferrous cuts

Compatibility

Designed as a straight-shank interchangeable pilot counterbore for use with 1/4 inch pilot shanks; compatible with standard 3/4 inch straight-shank toolholding setups on drill presses, milling machines, and similar machine tools.

Installation Notes

Installation and use should be performed by a qualified machinist or toolroom technician. Secure the 3/4 inch shank firmly in a properly sized collet or drill chuck before operation, and verify the pilot is fully seated and locked before cutting. Power down and de-energize the machine spindle completely before changing pilots or removing the tool. Cutting speeds and feeds should follow the tooling manufacturer or standard HSS counterbore recommendations for the work material being machined.