Value Collection GH8840506 Counterbore 25/32 in 4 Flute Hss

Product Description

The VALUE COLLECTION GH8840506 is a 4-flute interchangeable pilot counterbore designed for precision enlarging and finish-cutting of counterbored holes in metal workpieces. Built from high speed steel with a bright, uncoated finish, this tool accepts a 3/16 inch pilot shank and is mounted via a 1/4 inch straight shank for compatibility with standard drill chucks and collet holders. At 3.125 inches overall length, it provides adequate reach for most production and maintenance drilling setups. Right-hand cutting direction and aircraft-style geometry make it a practical choice for general metalworking and aerospace-adjacent applications where close-tolerance counterboring is required.

This counterbore is suited for use in machine shops, aircraft maintenance facilities, and general metalworking environments. It is typically used with a drill press, milling machine, or hand drill to produce clean, flat-bottomed counterbores that seat socket-head cap screws flush with or below the workpiece surface. The interchangeable pilot design allows the same body to be used with different pilot diameters, adding flexibility to a standard tooling inventory. Machinists and maintenance mechanics are the primary users of this tool type.

Key Features

• 25/32 inch counterbore diameter for precision flat-bottom hole finishing
• 4-flute geometry for smooth chip evacuation and surface finish
• High speed steel construction for durability in ferrous and non-ferrous metals
• Interchangeable pilot accepts 3/16 inch pilot shank
• 1/4 inch straight shank fits standard drill chucks and collet systems
• Aircraft-style design for close-tolerance counterboring applications
• Bright uncoated finish for easy wear inspection

Compatibility

Compatible with 3/16 inch interchangeable pilots. Designed as a straight-shank counterbore for use in any 1/4 inch capacity drill chuck or collet holder on drill presses, milling machines, or similar equipment.

Installation Notes

Installation is performed by machinists or maintenance mechanics using a drill press, milling machine, or equivalent rotating equipment. Secure the 1/4 inch straight shank firmly in a properly sized collet or drill chuck before operation and verify the pilot is fully seated and locked before cutting. Run at appropriate surface feet per minute for the workpiece material and use cutting fluid where recommended for high speed steel tooling. Inspect the pilot and cutting edges for wear before each use to maintain dimensional accuracy.