Value Collection GH8790529 Pilot Counterbore 13/16 in Hss

Product Description

The VALUE COLLECTION GH8790529 is a three-flute interchangeable pilot counterbore designed for precision enlarging and finishing of bolt-seat recesses in metal workpieces. Built from high-speed steel with a bright, uncoated polished finish, it delivers reliable cutting performance in general machining and fabrication environments. The straight shank measures 5/8 inches in diameter and 3-7/8 inches in length, with an overall length of 5-3/8 inches. The counterbore diameter is 13/16 inches, and it accepts a 1/4-inch pilot shank for accurate hole alignment. Right-hand cutting direction is standard. This tool is installed and used by machinists, tool-and-die technicians, and maintenance mechanics.

This counterbore is suited for use in drill press, milling machine, or hand-held power drill applications where a flat-bottomed recess is required for fastener seating. Typical applications include creating counterbores for socket head cap screws, machine bolts, and similar hardware in steel, aluminum, and other machinable materials. The interchangeable pilot design allows the pilot to be swapped out for different clearance hole diameters without replacing the counterbore body, making it practical for shops working across multiple fastener sizes.

Key Features

• 13/16-inch counterbore diameter for standard fastener recess applications
• High-speed steel construction provides wear resistance in ferrous and non-ferrous materials
• Three-flute geometry promotes smooth cutting and reduces chatter
• Interchangeable pilot accepts 1/4-inch pilot shank for precise hole alignment
• Bright, uncoated polished finish suitable for general-purpose machining
• Straight 5/8-inch shank is compatible with standard drill chucks and milling holders

Compatibility

Designed as an OEM-style replacement or direct-use interchangeable pilot counterbore compatible with standard straight-shank toolholders and drill chucks accepting a 5/8-inch shank diameter.

Installation Notes

Secure the straight shank firmly in a drill chuck or milling collet rated for 5/8-inch shanks before operation. Ensure the workpiece is clamped and the pilot is correctly seated in the pilot hole to prevent tool walking or oversizing the recess. Run at appropriate spindle speeds for the workpiece material and tool diameter per standard machining practice. Inspect the pilot and cutting edges for wear before each use.