Heli-coil A1191-7CN438 7/16-20 Unf Threaded Insert

Product Description

The HELI-COIL A1191-7CN438 is a free running wire thread insert designed to create or restore durable internal threads in tapped holes. Manufactured from 304 stainless steel with a bright uncoated finish, this insert accepts a 7/16-20 UNF thread and measures 0.438 inches in overall length, representing a 1D length-to-diameter ratio. The tanged design allows for installation using a standard HELI-COIL installation tool, and the tang is removed after seating. This insert suits applications where corrosion resistance and thread integrity are priorities in metalworking, maintenance, and repair operations.

This insert is used in thread repair and new thread installation applications across industrial, mechanical, and equipment maintenance environments. It is well suited for ferrous and non-ferrous base materials where stripped or weak threads need reinforcement. Installers in manufacturing, field maintenance, and equipment service operations use free running inserts of this type to restore OEM thread dimensions without replacing the parent part. The single-insert package accommodates targeted repairs, with a minimum order quantity of 10 units.

Key Features

• 7/16-20 UNF thread size for fine-pitch fastener applications
• 0.438 inches overall length with a 1D length-to-diameter ratio
• 304 stainless steel construction for corrosion resistance
• Tanged design for controlled installation and positive seating
• Bright uncoated finish - no coating interference with thread fit
• 6-5/8 free coils for consistent thread engagement

Compatibility

Designed as an OEM-style thread repair insert for any application requiring a 7/16-20 UNF internal thread in a standard free running insert configuration.

Installation Notes

Installation requires a HELI-COIL or compatible wire thread insert installation tool sized for 7/16-20 UNF. The parent hole must be drilled and tapped to the correct HELI-COIL oversized tap dimension before inserting. After the insert is fully seated, remove the drive tang using a tang break-off tool or punch. Power down or de-energize any equipment before performing thread repair on in-service components.