Value Collection GH8815219 Pilot Counterbore 21/64in

Product Description

The VALUE COLLECTION GH8815219 is a 3-flute interchangeable pilot counterbore designed for precision countersinking and seat preparation in metal fabrication and machining applications. Built from cobalt steel with a bright, uncoated finish, it delivers durability in demanding cutting conditions. The tool features a 21/64-inch counterbore diameter and a 5/16-inch straight shank, making it compatible with standard drill press and milling machine setups. Right-hand cutting geometry ensures clean, consistent material removal. With an overall length of 3-13/16 inches, this counterbore suits a range of workpiece depths encountered in general machining and assembly operations.

This interchangeable pilot counterbore is intended for use in machine shops, aerospace fabrication, and general metalworking environments where accurate bolt-seat or fastener-head recesses are required. The cobalt construction makes it well-suited for harder ferrous materials, stainless steels, and high-temperature alloys where high-speed steel tooling may underperform. A licensed machinist or tool-and-die professional typically installs and operates this type of cutting tool in production or maintenance contexts.

Key Features

• 21/64-inch counterbore diameter for precise fastener-head seating
• Cobalt steel construction for improved heat and wear resistance in hard materials
• 3-flute design provides balanced cutting action and smooth finish
• Straight 5/16-inch shank for compatibility with standard drill chucks and collets
• Bright, uncoated finish suitable for use with cutting fluids
• Right-hand cutting direction for use in standard spindle rotation setups

Compatibility

Designed for use with interchangeable pilots with a 3/32-inch pilot shank diameter. Fits standard straight-shank tool holders and drill chucks accepting a 5/16-inch shank.

Installation Notes

Installation and operation should be performed by a qualified machinist familiar with rotary cutting tools and machine tool setups. Secure the straight shank firmly in a matching collet or drill chuck before operation, and confirm the pilot fits freely in the pre-drilled pilot hole. Always power down and lock out the spindle before changing the pilot or inspecting the cutting edges. Use an appropriate cutting fluid for the workpiece material to extend tool life and improve surface finish.