Heli-coil 05CBB Hand Sti Tap 5-40 Unc H1 Bottoming

Product Description

The HELI-COIL 05CBB is a hand STI tap designed to cut threads for Heli-Coil screw thread inserts in 5-40 UNC applications. It features a bottoming chamfer for threading close to the bottom of blind holes, a 3-flute geometry that clears chips efficiently in short-run and hand-tapping operations, and an H1 thread limit for tight tolerance control. The tap is manufactured from high-speed steel with a bright uncoated finish, offering reliable wear resistance for production and repair work. Overall length is 2.125 inches with a 0.75-inch thread length. Licensed machinists, maintenance technicians, and field repair professionals working with threaded inserts are the primary users of this tap.

This tap is used in applications where a stripped or damaged threaded hole is being repaired or where a new STI thread is being cut to accept a Heli-Coil insert. Typical scenarios include aerospace, automotive, industrial machinery, and general metalworking environments where restoring or creating accurate 5-40 UNC threads is required. The bottoming chamfer style makes it especially suited for blind holes where a standard or plug chamfer would leave unthreaded material at the base. Class of fit is 3B, appropriate for standard tolerance threaded connections.

Key Features

• Bottoming chamfer for threading to the base of blind holes
• H1 thread limit for consistent, close-tolerance thread production
• 3-flute design promotes chip evacuation during hand tapping
• High-speed steel construction provides durability across ferrous and non-ferrous materials
• Bright uncoated finish suitable for use with standard cutting fluids
• Class 3B fit for standard precision threaded insert applications

Compatibility

Designed for use with Heli-Coil screw thread insert systems requiring a 5-40 UNC STI tapped hole. Intended for use with the corresponding Heli-Coil insert installation system for that thread size and standard.

Installation Notes

This tap should be installed by a machinist or trained technician familiar with STI tapping procedures and thread insert systems. Always secure the workpiece and use appropriate cutting fluid for the base material before tapping. Power down or de-energize any equipment before performing threaded hole repair on assembled components. Follow tap manufacturer guidelines for tapping depth to avoid tap breakage in blind holes.