Hertel K007008AS Sti Tap 5-40 Unc 2 Flute Plug Hss

Product Description

The HERTEL K007008AS is a spiral point STI tap designed for cutting Screw Thread Insert (STI) threads in a 5-40 UNC configuration. It features a plug chamfer style and a 2-flute spiral point geometry that pushes chips ahead of the tap during through-hole threading operations. Constructed from high-speed steel (HSS) with a bright, uncoated finish, this tap offers good performance in ferrous and non-ferrous materials. The overall length measures 2-1/8 inches, with a thread length of 3/4 inches. The thread limit is H1, making it appropriate for close-tolerance STI thread production where helicoil inserts will be installed.

This tap is used in maintenance, repair, and manufacturing applications where stripped or damaged threads need to be restored using helical wire thread inserts. The 5-40 UNC size is common in small fastener repair work found in precision assemblies, instrumentation panels, and light mechanical equipment. Installation is typically performed by machinists, tool and die technicians, and maintenance professionals working with tapping machines or hand tapping equipment. The Helicoil Reference Number for this tap is 05CSB.

Key Features

• Spiral point geometry pushes chips forward, suited for through-hole tapping
• STI UNC thread standard for use with helical wire thread inserts
• Plug chamfer style for standard starting and through-hole applications
• H1 thread limit for tight-tolerance STI thread cutting
• High-speed steel construction for durability in a range of workpiece materials
• Bright, uncoated finish with no added coating buildup on thread profile

Compatibility

Designed as an STI-style tap compatible with 5-40 UNC helical thread insert systems. The Helicoil Reference Number is 05CSB. Verify thread insert system requirements before use.

Installation Notes

STI taps should be installed by qualified machinists or maintenance technicians familiar with thread insert systems. Always secure the workpiece and ensure the tapping axis is properly aligned before starting the cut. Use appropriate tapping fluid for the workpiece material to extend tap life and improve thread quality. Power down or disengage any tapping machine before changing or inspecting the tap.