Value Collection GH8790248 Counterbore 3/8in 3 Flute Hss

Product Description

The VALUE COLLECTION GH8790248 is a 3-flute interchangeable pilot counterbore designed for precision enlarging and finishing of drilled holes to accept fastener heads in metal fabrication and machining applications. Built from high speed steel with a bright, uncoated finish, this counterbore measures 3/8 inches in diameter and accepts a 5/32-inch pilot shank for accurate hole centering. The straight shank measures 5/16 inches in diameter and 3-1/16 inches in length, with an overall length of 4-1/16 inches. Right-hand cutting direction and a polished surface finish contribute to clean, consistent results in production and repair environments. Machinists and tool-and-die professionals are the primary users of this tooling.

This counterbore is suited for use in drill press, milling machine, and manual or CNC machining setups where a flat-bottomed recess is required for socket head cap screws, bolts, or other flush-mount fasteners. The interchangeable pilot design allows the same body to be used with different pilot diameters as job requirements change, reducing the need for multiple dedicated tools. Applications commonly include aerospace-adjacent fabrication, general metalworking, and maintenance repair operations on steel and similar materials.

Key Features

• 3/8-inch counterbore diameter for standard fastener head recessing
• High speed steel construction for durability in metal cutting applications
• 3 flutes for efficient chip evacuation and smooth finish
• Interchangeable pilot accepts 5/32-inch pilot shank for repeatable hole centering
• Straight 5/16-inch shank compatible with standard drill chucks and collets
• Bright, uncoated finish with polished surface for reduced friction during cutting

Compatibility

Designed as an OEM-style interchangeable pilot counterbore for use in standard drill presses, milling machines, and similar metalworking equipment that accept a 5/16-inch straight shank tooling.

Installation Notes

Installation is typically performed by a machinist or skilled fabricator. Secure the straight shank firmly in a drill chuck or collet before operation, and confirm the correct pilot diameter is seated before cutting. Ensure the workpiece is clamped securely and the spindle speed is appropriate for the material and tool diameter. Do not exceed the recommended RPM for high speed steel tooling in the material being cut.