Heli-coil A1191-4CN500 1/4-28 Unf Insert 0.5in Tanged Ss

Product Description

The HELI-COIL A1191-4CN500 is a free running helical wire threaded insert designed to create strong, wear-resistant internal threads in parent materials that require reliable fastening. Manufactured from 304 stainless steel with a bright, uncoated finish, this insert accepts a 1/4-28 UNF thread and measures 0.5 inches in overall length, corresponding to a 2D length-to-diameter ratio. With 11-3/8 free coils, it provides full thread engagement across its length. Licensed machinists, maintenance technicians, and assembly professionals install these inserts to restore stripped threads or to establish new threaded holes in softer base materials.

This insert is suited for applications in industrial assembly, mechanical maintenance, and precision repair work where a 1/4-28 UNF internal thread is required. The tanged design is compatible with standard HELI-COIL installation tools, making it a common choice on production lines, in field repair kits, and in MRO settings. The 304 stainless steel construction holds up in environments with exposure to moisture or mild corrosives, making it a practical choice for both indoor and light outdoor assemblies.

Key Features

• Thread size 1/4-28 UNF for precise inch-series fine-thread fitment
• 0.5 inch overall length with 2D length-to-diameter ratio for solid thread engagement
• 304 stainless steel construction provides corrosion resistance and durability
• Tanged design works with standard HELI-COIL insertion tools for consistent installation
• 11-3/8 free coils deliver full load distribution along the threaded bore
• Bright, uncoated finish maintains dimensional accuracy without coating buildup

Compatibility

Designed as an OEM-style free running insert for use in any application requiring a 1/4-28 UNF internal thread repair or new-thread installation using a standard HELI-COIL-compatible insertion tool.

Installation Notes

Installation requires a properly sized HELI-COIL tap to prepare the parent material bore before inserting. Power down or de-energize any equipment before performing thread repair on assembled components. Use the correct HELI-COIL insertion tool matched to the 1/4-28 thread size to drive the insert to the proper depth. After installation, remove the tang using a tang break-off tool where required by the application.