Value Collection GH8790636 Counterbore 63/64 in 3 Flute Hss

Product Description

The VALUE COLLECTION GH8790636 is a 3-flute interchangeable pilot counterbore designed for precision enlarging and finishing of drilled holes in metalworking applications. Built from high speed steel with a bright, uncoated finish, this tool delivers reliable performance in production and maintenance environments. It features a 63/64 inch counterbore diameter, a 3/4 inch straight shank, and a 6-3/8 inch overall length. The interchangeable pilot design accommodates a 5/16 inch pilot shank, allowing the tool to be adapted to different pilot sizes without replacing the body. Right-hand cutting direction is standard. Machinists, tool and die workers, and general machine shop personnel are the primary users.

This counterbore is suited for use in manual mills, drill presses, and CNC machining centers where spot-facing or counterboring operations are required to seat fastener heads flush or below a workpiece surface. It is appropriate for ferrous and non-ferrous metals in both production and job-shop settings. The straight shank allows direct mounting in a drill chuck or collet holder with a matching 3/4 inch bore. The 4-5/8 inch shank length provides adequate reach for most standard fixturing setups.

Key Features

• 63/64 inch counterbore diameter for close-tolerance fastener seat preparation
• High speed steel construction for durability across ferrous and non-ferrous materials
• 3-flute geometry promotes smooth chip evacuation and consistent finish
• Interchangeable pilot accepts 5/16 inch pilot shank diameter
• Straight 3/4 inch shank for direct chuck or collet mounting
• Bright, uncoated finish — no coating buildup concerns in precision bores

Compatibility

Designed as an OEM-style interchangeable pilot counterbore for use in standard drill press, manual milling machine, and CNC machining center setups requiring a 3/4 inch straight shank holder and a 5/16 inch pilot shank.

Installation Notes

Installation should be performed by a qualified machinist. Secure the straight shank firmly in a 3/4 inch drill chuck or collet before operation, and confirm the pilot is properly seated before beginning the cut. Power down the machine completely before changing pilots or inspecting the cutting edges. Do not exceed the recommended feed and speed parameters for high speed steel tooling in the workpiece material being machined.