Hertel K007301AS Spiral Flute Sti Tap 2-56 Unc Hss

Product Description

The HERTEL K007301AS is a spiral flute STI (Screw Thread Insert) tap designed for cutting internal threads that will accept Helicoil-style thread inserts. Ground from high-speed steel with a bright finish, this tap features a 2-56 UNC thread form, 2 flutes, and a 52-degree helix angle. The steep helix promotes efficient chip evacuation in blind and through holes. The bottoming chamfer allows threading close to the bottom of a blind hole, making this tool well suited for applications where thread depth is limited. Overall length is 1-7/8 inches.

This tap is used wherever a 2-56 UNC STI thread is required before installing a Helicoil or equivalent wire thread insert. Typical applications include repair of stripped threads in aluminum, magnesium, and other softer alloys, as well as original equipment manufacturing in aerospace, electronics, and precision instrument assembly. The fine 2-56 thread size is common in small-fastener and instrument work. The Helicoil reference number for this tap is 6905-02.

Key Features

• 2-56 UNC STI thread form for use with Helicoil-style wire thread inserts
• 52-degree spiral flute helix angle for positive chip evacuation in blind holes
• Bottoming chamfer allows threading to near the bottom of a blind hole
• High-speed steel construction provides wear resistance across a range of workpiece materials
• Bright finish suitable for general-purpose tapping applications
• H2 thread limit for controlled tolerance on the STI thread form

Compatibility

Compatible with Helicoil-style screw thread insert systems; Helicoil reference number 6905-02. Designed as an OEM-style STI tap for 2-56 UNC thread insert applications.

Installation Notes

This tap is installed by qualified machinists or maintenance technicians using a standard tap wrench or machine tap holder. Always use cutting fluid appropriate for the workpiece material to extend tool life and improve thread finish. Drill the correct STI tap drill size for the 2-56 UNC insert before tapping. Do not exceed the recommended cutting speed for high-speed steel tooling in the material being tapped.