Value Collection GH8790396 Counterbore 39/64 in 3 Flute Hss

Product Description

The VALUE COLLECTION GH8790396 is a 3-flute interchangeable pilot counterbore designed for precision counterboring operations in metal fabrication and machining applications. Built from high speed steel with a bright, uncoated finish, this tool delivers consistent cutting performance in drilling and boring setups. The straight shank measures 1/2 inch in diameter and 3-7/8 inches in length, with an overall length of 5-1/8 inches. The 39/64-inch counterbore diameter is paired with a 3/16-inch pilot shank compatibility, making it suitable for controlled spot-facing and counterboring of bolt-hole patterns and fastener seats.

This counterbore is used in machine shop, manufacturing, and maintenance environments where accurate fastener recessing is required. It is compatible with standard drill press, milling machine, and CNC setups that accept straight shank tooling. Right-hand cutting geometry makes it appropriate for conventional clockwise-spindle equipment. Machinists and maintenance technicians working with bolt flange preparations and precision hole finishing will find this tool a reliable fit for standard production and repair workflows.

Key Features

• 39/64-inch counterbore diameter for precise fastener seat preparation
• High speed steel construction for durability in ferrous and non-ferrous materials
• 3-flute design provides balanced cutting action and chip evacuation
• Straight shank at 1/2 inch diameter for secure chuck retention
• Bright, uncoated polished finish suitable for general-purpose machining
• Right-hand cutting direction compatible with standard spindle rotation

Compatibility

Designed for use with interchangeable pilot counterbore systems accepting a 3/16-inch pilot shank and a 1/2-inch straight shank. Fits standard drill press, milling machine, and CNC spindle chucks designed for straight shank tooling.

Installation Notes

Installation should be performed by a qualified machinist familiar with rotating cutting tool procedures. Secure the straight shank firmly in a compatible chuck before operation and verify that spindle speed is appropriate for the workpiece material and tool diameter. Always power down and lock out the spindle before changing pilots or inspecting the cutting edges. Do not exceed the tool's rated operating parameters for feed rate or depth of cut.