Value Collection GH8830168 Counterbore 1/4in 4 Flute Hss

Product Description

The VALUE COLLECTION GH8830168 is a 4-flute interchangeable pilot counterbore designed for precision seat preparation in metal fabrication and aerospace-style drilling applications. The tool features a 0.25-inch counterbore diameter and a 15/64-inch straight shank, making it compatible with standard drill chucks and collet holders. Constructed from high speed steel (HSS) with a bright, uncoated polished finish, it delivers reliable performance in ferrous and non-ferrous materials. The aircraft-style geometry provides clean, flat-bottomed counterbore seats required for flush fastener installation. With a 4-inch overall length (OAL), it reaches deeper bores without requiring extension tooling.

This counterbore is suited for aircraft-style fastener seat preparation, machine shops, and general metalworking environments where interchangeable pilots allow a single body to serve multiple fastener sizes. The 3/32-inch pilot shank diameter compatibility allows the use of interchangeable pilots to guide the cut and maintain concentricity with a pre-drilled hole. Right-hand cutting direction is standard for use with conventional clockwise-rotation drill presses, CNC machines, and hand drills. Machinists, toolmakers, and maintenance technicians in aerospace, automotive, and industrial fabrication settings will find this tool appropriate for their workflows.

Key Features

• 0.25-inch counterbore diameter for precise flat-bottomed seat preparation
• Interchangeable pilot system accepts 3/32-inch shank diameter pilots for guided, concentric cuts
• 4-flute design improves chip evacuation and surface finish quality
• High speed steel construction provides durability in ferrous and non-ferrous materials
• Aircraft-style geometry engineered for flush fastener seating
• Bright, uncoated polished finish suitable for general-purpose machining without coolant-reactive coatings

Compatibility

Designed for use with interchangeable pilot counterbore systems accepting a 15/64-inch straight shank. Compatible with pilots having a 3/32-inch shank diameter. Fits standard drill chucks and collet holders used on drill presses, mills, and CNC machining centers.

Installation Notes

Installation and use should be performed by a qualified machinist or toolmaker familiar with rotating cutting tool safety. Secure the straight shank firmly in a properly sized collet or drill chuck before operation. Ensure the workpiece is clamped securely to prevent movement during the counterboring operation. Verify pilot fit and concentricity with the pilot hole before engaging the cutter to avoid tool deflection or workpiece damage.