Heli-coil A4184-3CN030 Screw-locking Insert M3 X 0.50

Product Description

The HELI-COIL A4184-3CN030 is a tangless screw-locking helical coil insert designed to create a durable, vibration-resistant threaded hole in a parent material. It accepts an M3 x 0.50 metric coarse fastener and has a 1D length-to-diameter ratio, giving it a 3.00 mm overall installed length. Manufactured from Grade 304 stainless steel with a bright finish, this insert resists corrosion in demanding environments. It is installed without a tang, eliminating the tang-removal step after installation. Maximum locking torque is 0.44 N/m with a minimum breakaway torque of 0.10 N/m. Machinists, MRO technicians, and assembly professionals use this insert to repair stripped threads or build new threaded connections in materials that cannot support a standard tapped thread alone.

This insert is suited for applications where a small-diameter, fine-pitch metric thread must hold under vibration or cyclic loading. Typical install scenarios include precision equipment assemblies, aerospace-grade component repair, electronics enclosures, and light mechanical assemblies requiring a corrosion-resistant thread form. The tangless design is compatible with standard HELI-COIL tangless installation tooling and is used wherever tang removal in a blind hole would be impractical. The minimum outside diameter of 3.80 mm and maximum outside diameter of 4.35 mm define the tap drill and pre-tapped hole requirements for correct fitment.

Key Features

• Tangless design eliminates the tang-break and removal step after installation
• Grade 304 stainless steel construction for corrosion resistance in wet or chemically active environments
• M3 x 0.50 metric coarse thread with 1D length-to-diameter ratio for low-profile thread repair
• 3-3/4 free coils provide consistent locking engagement across the thread length
• Maximum locking torque of 0.44 N/m controls fastener movement under vibration
• Bright finish provides clean visual confirmation of correct seating

Compatibility

Designed as an OEM-style screw-locking insert for use in any parent material pre-tapped to the M3 x 0.50 HELI-COIL specification, requiring a pre-tapped hole accepting an outside diameter between 3.80 mm and 4.35 mm.

Installation Notes

Installation is performed by machinists or assembly technicians using HELI-COIL tangless installation tooling matched to the M3 thread size. The parent material must be pre-tapped with the correct HELI-COIL tap to achieve the proper minor diameter before insert installation. Ensure the work piece is secured and the tapped hole is clean and free of debris before driving the insert. Do not use standard tang-type installation tools with this tangless insert, as doing so will damage the coil.