Value Collection GH8791329 Counterbore 1-1/2 in 5 Flute Hss

Product Description

The VALUE COLLECTION GH8791329 is a 5-flute interchangeable pilot counterbore designed for precision counterboring operations in metal fabrication and machining environments. Built from high speed steel with a bright, uncoated finish, it produces clean, flat-bottomed recesses for socket head cap screws and similar fasteners. The counterbore measures 1-1/2 inches in diameter with a 1-1/4-inch straight shank, giving it solid tool-holder engagement and reduced runout during operation. Overall length is 7-7/8 inches, with a shank length of 5-7/8 inches. The interchangeable pilot design accepts a 3/8-inch pilot shank, allowing the cutting head to be swapped without replacing the full tool assembly. Machinists, tool-and-die makers, and maintenance technicians working in job shops, manufacturing facilities, and industrial maintenance settings are the primary users.

This counterbore is suited for right-hand cutting in ferrous and non-ferrous metals where accurate bolt-seat geometry is required. The 5-flute configuration provides a good balance of chip clearance and surface finish quality, making it appropriate for production runs and precision one-off work alike. Typical applications include preparing bolt holes in structural steel, machinery frames, and fabricated assemblies where fastener heads must sit flush or recessed. The interchangeable pilot feature is especially useful when working with multiple hole sizes, as pilots can be changed to match varying drill diameters without swapping the body.

Key Features

• 1-1/2 inch counterbore diameter for large-diameter fastener seat preparation
• 5-flute geometry balances chip evacuation with smooth finish quality
• Interchangeable pilot accepts 3/8-inch pilot shank for versatile hole sizing
• High speed steel construction provides durability across ferrous and non-ferrous materials
• Bright, uncoated finish allows visual wear monitoring during use
• Straight 1-1/4-inch shank compatible with standard milling and drill press chucks

Compatibility

Designed for use with standard straight-shank tool holders and drill press chucks sized for a 1-1/4-inch shank. Accepts a 3/8-inch interchangeable pilot shank as specified.

Installation Notes

This tool is installed and operated by machinists and tool-and-die professionals using milling machines, drill presses, or similar equipment. Secure the straight shank fully in a properly rated chuck or collet holder before operation. Ensure the pilot is fully seated and locked before beginning the cut. Inspect the cutting edges and pilot fit before each use; do not operate with a loose or worn pilot, as this will compromise hole concentricity.