Heli-coil AT3585-04C168 Screw-locking Insert 4-40 Unc

Product Description

The HELI-COIL AT3585-04C168 is a tangless screw-locking helical coil insert designed to create durable, vibration-resistant threaded connections in tapped parent material. Manufactured from Grade 304 stainless steel with a bright finish, it accepts a 4-40 UNC mating thread and measures 0.168 inches in overall length, corresponding to a 1-1/2D length-to-diameter ratio. With a maximum locking torque of 48 oz-in and a minimum breakaway torque of 10 oz-in, it delivers reliable thread locking without adhesives or separate locking elements. The tangless design eliminates the need for tang removal after installation, reducing assembly steps and preventing loose tang debris inside assemblies.

This insert is suited for applications where standard threads in aluminum, cast iron, plastics, or soft metals require reinforcement and locking retention. Typical use cases include precision equipment, electronics enclosures, instrument panels, and light mechanical assemblies where fine 4-40 UNC threads are common. The stainless steel construction offers corrosion resistance appropriate for both indoor industrial environments and moderate-exposure service conditions. Installation is performed by trained assembly technicians or field service personnel using compatible HELI-COIL tangless installation tooling.

Key Features

• Tangless design eliminates post-installation tang removal and prevents debris contamination
• Grade 304 stainless steel construction provides corrosion resistance and strength
• 4-40 UNC thread size with 1-1/2D length-to-diameter ratio for standard fine-thread applications
• Maximum locking torque of 48 oz-in with minimum breakaway torque of 10 oz-in
• Outside diameter range of 0.144 to 0.159 inches for proper installation fit
• 4-3/4 free coils and bright finish for consistent installation performance

Compatibility

Designed as an OEM-style screw-locking thread insert for parent material tapped to accept a 4-40 UNC helical coil insert; requires compatible HELI-COIL tangless installation and extraction tooling.

Installation Notes

Installation should be performed by a qualified assembly technician or maintenance professional using the correct tangless insert installation tool specified for 4-40 UNC inserts. The parent material must be drilled and tapped to the proper HELI-COIL insert tap drill size before installation. Ensure the assembly is de-energized and secure before performing any thread repair or insert installation in powered equipment. Do not attempt installation with standard tang-style tooling, as tangless inserts require dedicated drivers.