Heli-coil A3585-4CNW500 Screw-locking Insert 1/4-20 Unc

Product Description

The HELI-COIL A3585-4CNW500 is a tangless screw-locking helical coil insert designed to create durable, vibration-resistant threaded connections in parent materials that require reliable fastener retention. Manufactured from Grade 304 stainless steel with a dry film lubricant finish, this insert provides corrosion resistance and consistent locking performance. At a 2D length-to-diameter ratio and 0.5 inches overall length, it accommodates 1/4-20 UNC thread applications. A maximum locking torque of 30 inch-pounds and a minimum breakaway torque of 4.50 inch-pounds make it suitable for assemblies where controlled thread locking is critical. The tangless design eliminates the need for tang removal after installation, streamlining the installation process for mechanics and assemblers.

This insert is used in applications where standard threads in base materials such as aluminum, cast iron, or softer metals need to be reinforced or repaired to accept a 1/4-20 UNC fastener. Common install scenarios include industrial equipment maintenance, HVAC component housings, pump and compressor assemblies, and any fabricated metal enclosure requiring a secure, reusable threaded connection. The stainless steel construction suits environments with exposure to moisture, mild chemicals, or elevated temperatures where thread integrity must be maintained over repeated fastener cycles.

Key Features

• Tangless design eliminates post-installation tang removal, reducing installation steps and debris risk
• Grade 304 stainless steel construction for corrosion resistance in demanding environments
• Dry film lubricant finish supports consistent torque control during installation
• Maximum locking torque of 30 inch-pounds provides reliable vibration resistance
• Minimum breakaway torque of 4.50 inch-pounds ensures controlled removal when required
• 8 free coils and 2D length ratio deliver full thread engagement in standard boss depths

Compatibility

Designed as an OEM-style screw-locking insert for 1/4-20 UNC threaded applications requiring a 2D insert length in any parent material prepared with the appropriate HELI-COIL tap drill and installation tool.

Installation Notes

Installation is performed by machinists, maintenance mechanics, or trained technicians using the correct HELI-COIL tang-free installation tool and a properly sized tap drill for the parent material. The parent material bore must be tapped to the HELI-COIL specification for 1/4-20 UNC before the insert is driven in. Ensure the parent material is securely fixtured and depowered or depressurized before performing thread repair on any assembly in service. Follow applicable torque specifications for the mating fastener per the equipment manufacturer or applicable mechanical standards.