Value Collection GH8815409 Counterbore 5/8 in 3 Flute Cobalt

Product Description

The VALUE COLLECTION GH8815409 is a 3-flute interchangeable pilot counterbore designed for precision enlarging of pre-drilled holes to accept socket head cap screws, bolts, and similar fastener heads. Built from cobalt steel with a bright, uncoated finish, it delivers solid performance in tough materials including stainless steel and high-strength alloys. The straight shank measures 0.5 inches in diameter and 3.875 inches in length, with an overall tool length of 5.125 inches. The pilot accepts a 0.1875-inch pilot shank diameter. Right-hand cutting geometry and a cobalt steel construction make this a reliable choice for machinists and metalworkers in production and repair environments.

This counterbore is suited for general metalworking and machining operations where a flat-bottomed recess is needed above an existing bore. Typical applications include fabrication shops, aerospace maintenance, and industrial maintenance operations. It is used in manual mills, drill presses, and CNC setups where a straight shank toolholder is employed. The interchangeable pilot design allows the same body to be used with different pilot diameters, improving versatility across multiple job setups without requiring a dedicated tool for each fastener size.

Key Features

• Cobalt steel construction for heat and wear resistance in hard materials
• 3-flute design provides smooth cutting action and efficient chip evacuation
• Bright, uncoated finish suited for a wide range of workpiece materials
• Interchangeable pilot system allows use with multiple pilot sizes
• Right-hand cutting direction for standard mill and drill press setups
• Straight shank compatible with standard collet chucks and drill chucks

Compatibility

Designed for use with a 0.1875-inch pilot shank diameter. Compatible with straight shank toolholders, collet chucks, and drill press chucks accepting a 0.5-inch shank. Interchangeable pilot design allows use with separately sourced pilots of appropriate diameter.

Installation Notes

This tool is installed and operated by machinists and tool-and-die professionals using a mill, drill press, or similar machine tool. Secure the straight shank firmly in a collet or chuck before operation, and ensure the pilot is properly seated and locked before cutting. Always bring the spindle to the correct speed for the workpiece material before engaging the cut, and allow chips to clear regularly to prevent heat buildup. Follow your facility's lockout/tagout procedures when changing tooling or adjusting setups.