Value Collection GH8816241 Counterbore 1-3/8 in 5 Flute

Product Description

The Value Collection GH8816241 is a 5-flute interchangeable pilot counterbore designed for precision recess-cutting in metalworking and machining applications. Built from cobalt steel with a bright, uncoated finish, this counterbore delivers the hardness and heat resistance needed for cutting tough alloys and hardened steels. It features a 1-3/8 inch cutting diameter, a 1 inch straight shank, and a 6-5/8 inch overall length. The interchangeable pilot design accepts a 3/8 inch pilot shank, allowing technicians to swap pilots for different fastener clearance requirements without replacing the body. Right-hand cutting direction is standard.

This counterbore is used in machine shops, maintenance facilities, and aerospace or industrial fabrication environments where countersunk or counterbored holes are required for cap screws, bolts, or socket head fasteners. The cobalt construction makes it suitable for harder workpiece materials where high-speed steel tooling would wear prematurely. It is typically run on a drill press, milling machine, or CNC machining center. The 4-5/8 inch shank length provides solid grip and reduced runout in standard tool holders.

Key Features

• 1-3/8 inch counterbore diameter for standard cap screw seating
• Cobalt steel construction for improved heat and wear resistance over standard HSS
• 5-flute geometry for smooth cutting action and improved surface finish
• Interchangeable pilot accepts 3/8 inch pilot shank for flexible fastener compatibility
• Bright, uncoated finish suitable for use with cutting fluids
• Right-hand cutting direction for standard machine spindle use

Compatibility

Designed for use with 3/8 inch interchangeable pilots. Fits standard straight-shank tool holders with a 1 inch bore. Suitable for drill presses, milling machines, and CNC machining centers configured for straight-shank counterbore tooling.

Installation Notes

Installation and operation should be performed by a qualified machinist. Secure the 1 inch straight shank firmly in a collet or drill chuck rated for the shank diameter before operation. Ensure the pilot is fully seated and locked before cutting to prevent lateral movement and oversized holes. Apply appropriate cutting fluid for the workpiece material to extend tool life and improve finish quality.