Value Collection GH8840647 Counterbore 1 in 4 Flute Hss

Product Description

The VALUE COLLECTION GH8840647 is a 1-inch diameter interchangeable pilot counterbore designed for precision counterboring operations in metal fabrication and aircraft-style applications. Built from high-speed steel with a bright, uncoated polished finish, this tool delivers reliable cutting performance across a range of ferrous and non-ferrous materials. The 4-flute design provides smooth chip evacuation and a clean seat finish. The straight shank measures 1/4 inch in diameter and the tool has an overall length of 3.125 inches. Right-hand cutting direction makes it compatible with standard drill press and CNC setups. Licensed tradespeople and machinists in aerospace, industrial maintenance, and fabrication shops will find this counterbore ready to work out of the package.

This counterbore is suited for creating flat-bottomed recesses for socket head cap screws and similar fastener heads in structural and sheet metal assemblies. The interchangeable pilot design accepts a 3/16-inch pilot shank, allowing the tool to be guided precisely along a pre-drilled hole. Aircraft-style geometry makes it appropriate for tight-tolerance work where seat concentricity matters. It is used in both production and repair environments by machinists, aircraft maintenance technicians, and industrial fabricators.

Key Features

• 1-inch counterbore diameter for standard socket head fastener clearance
• High-speed steel construction for durability across a range of workpiece materials
• 4-flute cutting geometry for smooth chip flow and clean seat finish
• Interchangeable pilot accepts 3/16-inch pilot shank for guided, concentric boring
• Bright uncoated polished finish reduces friction and aids chip release
• Aircraft-style design for tight-tolerance and structural fabrication applications

Compatibility

Designed for use with interchangeable pilot systems accepting a 3/16-inch pilot shank diameter. Compatible with standard drill press, mill, and CNC spindles fitted with a 1/4-inch straight shank collet or chuck.

Installation Notes

Installation should be performed by a qualified machinist or maintenance technician familiar with rotating cutting tools. Secure the 1/4-inch straight shank in a properly sized collet or drill chuck before operation, and confirm the pilot shank is seated firmly before engaging the workpiece. Always power down and lock out the machine spindle before changing pilots or removing the tool. Use appropriate cutting fluid for the workpiece material to extend tool life and improve finish quality.