Value Collection GH8790420 Counterbore 21/32 in 3 Flute Hss

Product Description

The VALUE COLLECTION GH8790420 is a three-flute interchangeable pilot counterbore designed for precision counter-boring operations in metal fabrication and machining applications. Built from high-speed steel (HSS) with a bright, uncoated polished finish, this tool delivers consistent cutting performance at moderate speeds. It features a 21/32-inch counterbore diameter and a 1/2-inch straight shank, giving it reliable tool-holder compatibility. The right-hand cutting direction suits the overwhelming majority of standard drill press and milling setups. With a 5-1/8-inch overall length and a 3-7/8-inch shank length, the tool provides adequate reach for typical workpiece thicknesses encountered in production and maintenance environments.

This counterbore is suited for use in machine shops, maintenance facilities, and manufacturing operations requiring clean, flat-bottomed recesses for socket-head cap screws and similar fasteners. The interchangeable pilot design accepts a 3/16-inch pilot shank, allowing the same tool body to be used with different pilot sizes as the job demands. It is appropriate for use in drill presses, milling machines, and CNC machining centers where a 1/2-inch straight shank is accepted. Both production machinists and skilled maintenance technicians will find this tool fits standard workflows without modification.

Key Features

• 21/32-inch counterbore diameter for socket-head cap screw recessing
• High-speed steel construction for durability across a range of ferrous and non-ferrous materials
• Bright, uncoated polished finish reduces built-up edge in light-duty cutting applications
• Three-flute geometry balances chip evacuation with surface finish quality
• Interchangeable pilot accepts a 3/16-inch pilot shank for setup flexibility
• 1/2-inch straight shank provides broad compatibility with standard tool holders and chucks

Compatibility

Designed as an OEM-style replacement or standard-fit counterbore for drill presses, milling machines, and CNC machining centers accepting a 1/2-inch straight shank. Compatible with 3/16-inch interchangeable pilot shanks.

Installation Notes

Installation and use of this counterbore should be performed by a qualified machinist or maintenance technician familiar with rotating cutting tools. Secure the straight shank firmly in a properly sized chuck or collet before operation, and verify the pilot shank is fully seated before engaging the workpiece. Always power down and lock out the machine before changing pilots or inspecting the cutting edges. Follow applicable shop safety standards and the machine manufacturer guidelines for speed and feed recommendations based on workpiece material.