Hertel K011016AS Spiral Point Tap 4-40 Unc Hss

Product Description

The HERTEL K011016AS is a spiral point plug tap designed for cutting 4-40 UNC internal threads in through-hole applications. Built from high-speed steel with a bright uncoated finish, it features a 2-flute spiral point geometry that pushes chips ahead of the cutting edge, keeping the flutes clear and reducing the risk of chip packing in production environments. The H11 thread limit designation indicates a slightly oversized thread form, compensating for springback in tougher materials. Thread length is 9/16 inches and the shank diameter is 0.141 inches. This tap is suited for machinists, maintenance technicians, and toolroom professionals working on small-diameter threaded fastener applications.

This tap is used in machine tapping of through holes in ferrous and non-ferrous materials where chip evacuation is critical. The 4-40 UNC thread size is common in electronic enclosures, instrument panels, small mechanical assemblies, and precision sheet metal work. The plug chamfer provides a gradual thread lead-in, making it appropriate for both hand tapping and low-speed machine tapping setups. Right-hand thread cutting direction is standard for conventional 4-40 UNC fastener applications.

Key Features

• Spiral point geometry pushes chips forward, ideal for through-hole tapping
• H11 thread limit with 0.005 inch oversize for consistent thread fit after springback
• High-speed steel construction provides durability across a range of workpiece materials
• Bright uncoated finish suitable for general-purpose tapping without coolant-through requirement
• Plug chamfer for gradual thread engagement and controlled lead-in
• Right-hand cut, 4-40 UNC thread standard

Compatibility

Designed for use in standard 4-40 UNC through-hole tapping applications. Compatible with tap handles, tapping heads, and CNC machine tool holders configured for straight-shank taps with a 0.141-inch shank diameter.

Installation Notes

This tap should be installed by a machinist or qualified technician familiar with thread-cutting tooling and speeds. Secure the workpiece fully before tapping and use cutting fluid appropriate for the workpiece material to extend tool life. Ensure the tap is driven at a speed consistent with the material and tap diameter to avoid breakage. Inspect the tap and tap holder for runout before use, as small-diameter taps are sensitive to misalignment.