Hertel K007001AS Hand Sti Tap 4-40 Unc H1 Bottoming

Product Description

The HERTEL K007001AS is a hand STI tap designed to cut 4-40 UNC threads in through-hole and blind-hole applications. STI taps produce oversized threads intended for Heli-Coil and similar wire thread insert installations, restoring or upgrading thread strength in softer base materials. This tap features a bottoming chamfer, allowing threads to be cut close to the bottom of a blind hole. Manufactured from high-speed steel with a bright uncoated finish, it delivers consistent cutting performance in steel, aluminum, and similar machinable materials. The 3-flute geometry provides efficient chip evacuation in standard hand-tapping operations.

This tap is suited for maintenance, repair, and production work where 4-40 UNC wire thread inserts are required. Common applications include restoring stripped threads in aluminum housings, electronics enclosures, and light mechanical assemblies. With an overall length of 2 inches and a thread length of 11/16 inches, it fits standard tap handles used in bench and field work. Machinists, maintenance technicians, and precision assembly trades typically use this tool in low-volume and repair scenarios.

Key Features

• 4-40 UNC thread form sized for STI wire thread insert installation
• Bottoming chamfer allows threading to the base of blind holes
• 3-flute design promotes chip clearance during hand tapping
• High-speed steel construction provides durability across common machinable materials
• Bright uncoated finish for standard cutting applications
• Compact 2-inch overall length fits standard tap handles

Compatibility

Designed for use with 4-40 UNC Heli-Coil and compatible wire thread insert systems requiring an STI oversized tap in the H1 thread limit.

Installation Notes

This tap is intended for hand operation using a properly sized tap handle or T-handle wrench. Secure the workpiece before tapping and apply cutting fluid appropriate for the base material to extend tool life and improve thread finish. Use a tap guide where perpendicularity is critical. Back the tap off periodically to break chips and prevent binding in blind-hole applications.