Heli-coil A4184-8CN120 Threaded Insert M8 X 1.25 Ss

Product Description

The HELI-COIL A4184-8CN120 is a screw-locking helical wire thread insert designed to create a strong, vibration-resistant internal thread in tapped parent material. Manufactured from Grade 304 stainless steel with a bright finish, this tangless insert measures 12 mm in overall length at a 1-1/2D length-to-diameter ratio for an M8 x 1.25 metric coarse thread. The locking feature is built into the insert coil geometry, delivering a maximum locking torque of 6.00 N/m and a minimum breakaway torque of 0.80 N/m. Licensed machinists, maintenance technicians, and assembly professionals use this insert to restore or reinforce threaded holes in metal components.

This insert is suited for use in ferrous and non-ferrous base materials wherever metric coarse M8 x 1.25 thread engagement is required. Typical applications include repair of damaged threads, reinforcement of threads in soft alloys, and OEM assembly where vibration resistance is critical. The tangless design eliminates the need for tang removal after installation, reducing assembly steps and the risk of loose tang fragments in finished assemblies. Minimum outside diameter is 9.80 mm and maximum outside diameter is 10.35 mm, requiring a correctly sized STI (Screw Thread Insert) tap and installation tool.

Key Features

• Tangless design eliminates post-installation tang removal step
• Grade 304 stainless steel construction resists corrosion and oxidation
• Maximum locking torque of 6.00 N/m provides positive vibration resistance
• M8 x 1.25 metric coarse thread standard for broad fastener compatibility
• 12 mm overall length at 1-1/2D ratio delivers solid thread engagement depth
• Bright finish for easy visual inspection during and after installation

Compatibility

Designed for use in any tapped parent material prepared with a standard M8 x 1.25 STI tap, compatible with HELI-COIL tangless installation tooling for M8 metric coarse inserts.

Installation Notes

Installation requires an STI tap sized for M8 x 1.25 metric coarse and a tangless insert installation tool rated for this insert series. Power down or de-energize any equipment before performing thread repair on in-service components. Follow the tool manufacturer's installation procedure to seat the insert flush or slightly below the parent material surface. Do not use standard tang-style installation tools with tangless inserts, as they are not compatible.