Value Collection GH8831240 Counterbore 1-3/8 in 4 Flute Hss

Product Description

The VALUE COLLECTION GH8831240 is a 4-flute interchangeable pilot counterbore designed for precision counterboring operations in metalworking and fabrication applications. Built from high-speed steel with a bright, uncoated finish, this tool delivers consistent performance on ferrous and non-ferrous materials. The 1-3/8 inch counterbore diameter pairs with a 1/2 inch straight shank for secure tool holder engagement, and the 5-1/2 inch overall length provides adequate reach for standard machining setups. The aircraft-style geometry ensures clean, flat-bottomed seats for fastener heads in demanding industrial work.

This counterbore is suited for machine shops, maintenance facilities, aerospace fabrication environments, and general industrial production floors where counterbored fastener holes are required. The interchangeable pilot design allows the operator to swap pilots to match different fastener shank diameters without replacing the body, making it a practical choice for shops that work across multiple fastener sizes. A 1/4 inch pilot shank diameter compatibility is specified. Right-hand cutting direction is standard for conventional drill press and milling machine spindles.

Key Features

• 1-3/8 inch counterbore diameter for large-fastener seating applications
• High-speed steel construction provides durability across a range of workpiece materials
• 4-flute design promotes smooth cutting action and clean seat finish
• Interchangeable pilot system accepts 1/4 inch pilot shank diameter
• Aircraft-style geometry for flat-bottomed, precision counterbore seats
• Bright, uncoated finish suitable for use with cutting fluids

Compatibility

Compatible with tool holders and chucks accepting a 1/2 inch straight shank. Designed for use with interchangeable pilots with a 1/4 inch pilot shank diameter. Fits standard drill press, mill, or lathe spindle setups running right-hand rotation.

Installation Notes

Installation and operation should be performed by a qualified machinist familiar with rotating cutting tools and machine tool safety. Secure the straight shank firmly in a properly sized chuck or collet before operation, and verify the pilot is seated and locked before cutting. Always use an appropriate cutting fluid for the workpiece material to extend tool life and improve finish quality. Ensure the machine spindle is fully stopped and the tool is clear of the workpiece before making any adjustments.