Heli-coil 17551-4-5 Thread Insert Tool Replacement Blades 1/4-20

Product Description

The HELI-COIL 17551-4-5 is a set of replacement blades for the HELI-COIL hand installation tool used to install tangless thread inserts. The blades are the contact element that drives the insert into a prepared threaded hole without requiring a tang break-off step after installation. Designed for use with 1/4-20 UNC thread sizes, these replacement blades restore a worn or damaged installation tool to full working condition. Maintenance technicians, machinists, and field service professionals in HVAC, electrical, and mechanical trades rely on this consumable component to keep thread repair operations running without replacing the entire tool handle assembly.

These replacement blades are suited for any application where tangless thread inserts are being installed into 1/4-20 UNC threaded bores. Common use cases include thread repair and reinforcement on equipment housings, control panels, compressor bodies, and structural components in both residential and commercial service environments. The blades are specific to the hand installation tool format, making them appropriate for low-volume or field installation work where power tools are not practical or available.

Key Features

• Designed for tangless thread insert installation - no tang removal required after seating
• Compatible with 1/4-20 UNC thread size
• Replacement blades extend the service life of the existing hand installation tool body
• Conforms to UNC thread standard for use in standard inch-series threaded applications
• Lightweight at 0.1 pounds - suitable for tool kit and field carry

Compatibility

Designed as replacement blades for the HELI-COIL hand installation tool used with tangless thread inserts in 1/4-20 UNC applications.

Installation Notes

Installation of these replacement blades should be performed by a machinist or qualified mechanic familiar with thread insert tooling. Ensure the hand installation tool is fully disassembled and clear of any inserts before swapping blades. Follow the tool manufacturer's blade replacement procedure to ensure proper blade seating and alignment before returning the tool to service. Improper blade installation can damage thread inserts or the workpiece bore.