Value Collection GH8830408 Counterbore 5/8 in 4 Flute Hss

Product Description

The VALUE COLLECTION GH8830408 is a 4-flute interchangeable pilot counterbore designed for precision enlarging and finishing of drilled holes to seat fastener heads flush or below a workpiece surface. Built from high speed steel with a bright, uncoated finish, this tool features a 5/8-inch counterbore diameter and a 1/2-inch straight shank for secure chuck retention. At 4.25 inches overall length, it is sized for general-purpose countersinking work in metalworking and aircraft-style fabrication applications. The right-hand cutting direction suits standard drill press and milling machine setups. Machinists, toolmakers, and aerospace maintenance technicians are the primary users.

This counterbore is built for aircraft-style applications where precise, clean counterbore seats are required for flush or recessed fasteners. It accepts interchangeable pilots, allowing one tool body to serve multiple hole sizes with the correct pilot installed. The 1/8-inch pilot shank diameter compatibility accommodates standard pilot sizes. Suitable for use in ferrous and non-ferrous metals in both production and maintenance repair operations. Typical installations include airframe work, general machining, and precision assembly where fastener seating depth and concentricity are critical.

Key Features

• 5/8-inch counterbore diameter for accurate fastener seat sizing
• 4-flute geometry provides smooth cutting action and cleaner finishes
• High speed steel construction handles a range of metalworking materials
• Interchangeable pilot design for versatility across multiple hole sizes
• 1/2-inch straight shank for compatibility with standard chuck setups
• Bright, uncoated finish suited for use with cutting fluids

Compatibility

Designed for use with interchangeable pilots having a 1/8-inch pilot shank diameter. Compatible with standard drill press, milling machine, and hand-held drill motor setups that accept a 1/2-inch straight shank tool.

Installation Notes

Installation and use should be performed by a qualified machinist or maintenance technician familiar with rotating cutting tool safety. Secure the shank firmly in the chuck and verify the correct pilot is seated before operation. Always bring the spindle to a full stop before changing pilots or inspecting the tool. Use appropriate cutting fluid for the material being machined to extend tool life and improve finish quality.