Heli-coil A3585-02CNPF129 Screw-locking Insert 2-56 Unc

Product Description

The HELI-COIL A3585-02CNPF129 is a tangless, screw-locking helical wire insert designed to create strong, repairable internal threads in parent materials where 2-56 UNC threads are required. Manufactured from Grade 304 stainless steel with a primer-free finish, this insert measures 0.129 inches in overall length at a 1-1/2D length-to-diameter ratio. The tangless design eliminates the need for tang break-off after installation, reducing debris risk in assemblies where foreign object damage is a concern. Installed by aerospace, defense, and precision manufacturing technicians, this insert locks against vibrational loosening with a maximum locking torque of 20 oz-in and a minimum breakaway torque of 3.00 oz-in.

This insert is suited for use in fine-pitch threaded assemblies where vibration resistance and thread repair are priorities. The 2-56 UNC thread size targets small-fastener applications common in electronics enclosures, instrument panels, and precision mechanical assemblies. The 5-1/4 free coil count and locking feature make it appropriate for applications subject to dynamic loads or repeated fastener cycling. Installation is performed using HELI-COIL compatible tangless installation tooling matched to the 2-56 thread size.

Key Features

• Tangless design eliminates tang break-off step and prevents debris contamination in the assembly
• Screw-locking construction resists vibrational loosening up to 20 oz-in locking torque
• Grade 304 stainless steel construction provides corrosion resistance in demanding environments
• Primer-free finish suitable for direct installation without additional surface prep
• 0.129 inch overall length at 1-1/2D ratio fits standard insert pocket depths for 2-56 applications
• 5-1/4 free coils deliver consistent locking engagement across the thread engagement length

Compatibility

Designed as an OEM-style screw-locking thread insert for parent material bores prepared to accept 2-56 UNC helical wire inserts using compatible tangless installation tooling.

Installation Notes

Installation requires a tangless HELI-COIL installation tool sized for 2-56 UNC thread inserts - do not attempt installation with standard tang-type drivers. The parent bore must be drilled and tapped to the correct HELI-COIL tap drill size for 2-56 UNC before insert installation. Ensure the assembly is depowered and secured before performing thread repair or insert installation in electromechanical assemblies. Minimum breakaway torque of 3.00 oz-in must be verified per applicable inspection requirements after installation.