Hertel K007083AS Spiral Point Sti Tap 3/8-24 Unf

Product Description

The HERTEL K007083AS is a spiral point STI tap designed to cut internal threads in materials where a Helicoil-style thread insert will be installed. Built from high-speed steel with a bright, uncoated finish, this plug-chamfer tap drives chips forward through the hole rather than packing them into the flutes, making it well suited for through-hole tapping operations. At 3-5/32 inches overall length with a 1-7/16 inch thread length, the K007083AS cuts 3/8-24 UNF threads to an H3 thread limit, producing the oversized internal thread geometry required to accept a standard Helicoil insert. Three flutes provide a good balance of chip clearance and tool rigidity for this tap diameter. Licensed machinists, tool-and-die makers, maintenance technicians, and HVAC or mechanical contractors use STI taps when restoring stripped threads or installing thread inserts in aluminum, cast iron, steel, and similar materials.

This tap is intended for 3/8-24 UNF STI applications requiring thread insert installation. The plug chamfer, with its standard 3-5 thread lead-in, makes it suitable for through-holes and deep blind holes where adequate chip clearance exists. The H3 thread limit designation means the tap cuts slightly oversized to the UNF standard, which is the correct tolerance class for STI work. The Helicoil reference number for this tap is 6FSA. It is sold individually and is appropriate for both production and maintenance-repair-overhaul (MRO) use in machine shops, field service, and industrial maintenance environments.

Key Features

• Spiral point geometry pushes chips forward, reducing chip packing in through-hole applications
• H3 thread limit provides the oversized tolerance required for STI Helicoil insert installation
• High-speed steel construction offers good wear resistance across a broad range of workpiece materials
• Plug chamfer provides a 3-5 thread lead-in for reliable thread starts in through-holes and deep blind holes
• Bright, uncoated finish allows easy visual inspection of tool condition during use
• Compact 3-5/32 inch overall length fits standard tap handles and CNC toolholders for this size range

Compatibility

Designed for use in 3/8-24 UNF STI thread insert applications. Helicoil reference number 6FSA confirms fitment with standard 3/8-24 UNF Helicoil insert systems. Verify tap drill size per the thread insert manufacturer specifications before use.

Installation Notes

STI taps should be installed by qualified machinists or maintenance technicians familiar with thread insert systems. Always use the correct tap drill size specified for the insert being used, as drilling to standard UNF tap drill dimensions will not produce a usable result with this tap. Apply cutting fluid appropriate to the workpiece material and use consistent feed pressure to avoid tap breakage, particularly in blind-hole applications. De-burr and clean the hole before tapping to extend tool life and improve thread quality.