Heli-coil A1185-02CN258 2-56 Unc Free Running Insert

Product Description

The HELI-COIL A1185-02CN258 is a free running helical wire threaded insert designed to create or restore strong, wear-resistant threads in soft or damaged base materials. The insert is sized for a 2-56 UNC thread and measures 0.258 inches overall length, giving it a 3D length-to-diameter ratio suited for shallow-boss applications. Manufactured from 304 stainless steel with a bright, uncoated finish, it resists corrosion and handles repeated assembly cycles without galling. Machinists, maintenance technicians, and assembly professionals install this insert type when a parent material cannot hold a standard thread reliably on its own.

This insert is used in production assembly and repair scenarios where a 2-56 UNC internal thread is required in aluminum, magnesium, plastic, cast iron, or other materials with lower thread-holding strength than the fastener demands. The tanged design is compatible with standard HELI-COIL tangbreak installation tools and drive mandrels. With 11-7/8 free coils, the insert distributes fastener load evenly across the full installed length. Typical applications include instrument housings, electronic enclosures, small engine components, and precision mechanical assemblies.

Key Features

• 2-56 UNC thread size for fine-pitch small-fastener applications
• 0.258 inch overall length with a 3D length-to-diameter ratio
• 304 stainless steel construction for corrosion resistance and durability
• Tanged design for use with standard HELI-COIL installation tooling
• 11-7/8 free coils distribute clamping load along the full insert length
• Bright, uncoated finish maintains dimensional consistency without coating buildup

Compatibility

Designed as an OEM-style free running insert for use in any application requiring a 2-56 UNC internal thread repair or reinforcement in a pre-drilled and tapped HELI-COIL insert bore.

Installation Notes

Installation requires a properly sized HELI-COIL tap to prepare the parent material bore before the insert is driven in. A matched mandrel or drive tool threads the insert into the prepared bore until the top coil sits one-half turn below the surface. After installation, the tang is broken off using a tang breakoff tool. Power down or de-energize any assembly before performing thread repair work in an energized system, and follow applicable shop safety and torque procedures for the fastener and base material involved.