Heli-coil AT3591-3C285 Screw-locking Insert 10-32 Unf

Product Description

The HELI-COIL AT3591-3C285 is a screw-locking helical coil threaded insert designed to create strong, vibration-resistant internal threads in a tapped hole. Manufactured from Grade 304 stainless steel with a bright finish, this insert accepts a 10-32 UNF fastener and provides a 1-1/2D length-to-diameter ratio. The tangless design eliminates the need for tang removal after installation, reducing assembly steps and the risk of loose tang fragments in the assembly. It delivers a maximum locking torque of 13 inch-pounds and a minimum breakaway torque of 2 inch-pounds, making it well-suited for applications where fastener retention under vibration or repeated removal is critical.

This insert is used in metalworking, MRO, aerospace, automotive, and general industrial assembly where stripped, damaged, or weak parent-material threads must be restored or reinforced to full fastener load capacity. The 10-32 UNF thread is a common size in instrument panels, light structural assemblies, and equipment enclosures. Installation is performed with a standard helical insert installation tool sized for 10-32, using a pre-tapped hole prepared to the appropriate HELI-COIL tap specification. The tangless design is compatible with both manual and power installation drivers used in production environments.

Key Features

• Tangless design eliminates post-installation tang removal and prevents fragment contamination
• Grade 304 stainless steel construction resists corrosion in demanding service environments
• 10-32 UNF thread with 1-1/2D length-to-diameter ratio for balanced pull-out strength and thread engagement
• Maximum locking torque of 13 inch-pounds provides positive fastener retention under vibration
• Minimum breakaway torque of 2 inch-pounds allows controlled fastener removal without galling
• Bright finish, 6-7/8 free coils, overall insert length of 0.285 inches

Compatibility

Designed as an OEM-style replacement or new-installation insert for any application requiring a 10-32 UNF screw-locking helical coil insert in a parent material tapped to the corresponding HELI-COIL insert tap specification.

Installation Notes

Installation is performed by a machinist, assembler, or maintenance technician using a pre-tapped hole prepared with the correct HELI-COIL 10-32 STI tap. De-energize and lock out any equipment before performing thread repair on in-service assemblies. Use the appropriate tangless installation tool to drive the insert to the specified depth without over-driving. Verify thread engagement with the mating fastener before returning the assembly to service.