Heli-coil A3591-3CN380 Screw-locking Insert 10-32 Unf

Product Description

The HELI-COIL A3591-3CN380 is a tangless screw-locking helical thread insert designed to provide a secure, vibration-resistant threaded connection in tapped holes. Made from Grade 304 stainless steel with a bright finish, this insert accepts a 10-32 UNF fastener and delivers a locking function through a controlled interference fit between the insert coils and the mating screw. With an overall length of 0.38 inches and a 2D length-to-diameter ratio, it is suited for applications where thread stripping, corrosion, and loosening under load are primary concerns. Licensed mechanics, maintenance technicians, and assembly professionals install these inserts using standard HELI-COIL installation tooling.

This insert is used in applications requiring a durable, corrosion-resistant threaded repair or original-equipment thread reinforcement in metal or composite base materials. The 10-32 UNF thread size makes it common in light mechanical assemblies, instrumentation, and equipment housings where fine-thread fasteners are specified. The tangless design eliminates the need to remove a tang after installation, simplifying the installation process and reducing the risk of loose tang fragments contaminating assemblies. It is appropriate for both production and field repair scenarios where 304 stainless steel is compatible with the operating environment.

Key Features

• Grade 304 stainless steel construction resists corrosion in wet or chemically active environments
• Tangless design requires no tang removal after installation, reducing contamination risk
• 10-32 UNF thread form with 9-1/2 free coils provides consistent thread engagement
• Maximum locking torque of 13 inch-pounds with a minimum breakaway torque of 2.00 ounce-inches
• Overall length of 0.38 inches with a 2D length-to-diameter ratio for compact thread reinforcement
• Bright finish with outside diameter ranging from 0.236 to 0.256 inches for precise hole fit

Compatibility

Designed as an OEM-style or repair-grade thread insert for tapped holes requiring 10-32 UNF threading in metal, plastic, or composite base materials.

Installation Notes

Installation requires a HELI-COIL tap and installation tool matched to the 10-32 UNF thread size and 2D insert length. The base material must be tapped to the correct HELI-COIL oversize specification before insert installation. De-energize and lock out any equipment before performing thread repair on powered assemblies. Follow the insert manufacturer's tooling instructions to seat the insert flush with or slightly below the surface of the base material.