Heli-coil T3585-04C168S 4-40 Unc Locking Insert Ss 1000pk

Product Description

The HELI-COIL T3585-04C168S is a screw-locking helical coil insert designed to create a strong, vibration-resistant threaded connection in tapped holes. Built from Grade 304 stainless steel, this tanged insert installs into a standard Heli-Coil tapped hole and provides a 4-40 UNC internal thread at a 1-1/2D length. The overall insert length measures 0.168 inches. The locking feature is achieved through a deflected coil that applies radial pressure against the fastener, resisting loosening under vibration and dynamic loading. This insert is suited for use in metalworking, aerospace, electronics, and general industrial assembly applications.

This insert is used wherever a durable, corrosion-resistant threaded repair or thread reinforcement is needed in a 4-40 UNC tapped hole. The Grade 304 stainless steel construction makes it appropriate for applications exposed to moisture or mild corrosive environments. Typical installation scenarios include electronics enclosures, instrumentation panels, light-gauge metal assemblies, and precision mechanical components where thread stripping or vibration loosening is a concern. This product ships in a package quantity of 1000 inserts, making it suitable for production-level use.

Key Features

• Grade 304 stainless steel construction for corrosion resistance
• 4-40 UNC thread size with 1-1/2D length-to-diameter ratio
• Overall insert length of 0.168 inches
• Tanged design for standard Heli-Coil installation tooling
• Maximum locking torque of 48 oz-in; minimum breakaway torque of 10 oz-in
• 4-3/4 free coils for consistent thread engagement
• Outside diameter range of 0.144 to 0.159 inches for precise hole fit

Compatibility

Designed for use in standard Heli-Coil prepared tapped holes with 4-40 UNC thread specification. Compatible with the corresponding Heli-Coil tang break-off tool and installation driver for tanged inserts.

Installation Notes

Installation requires a Heli-Coil tap to prepare the receiving hole to the correct oversize diameter before insert installation. Use the appropriate Heli-Coil installation tool matched to the 4-40 insert size. After seating the insert flush or slightly below the surface, break off the installation tang using the designated tang break-off tool. Always verify thread engagement depth and torque requirements against the assembly specification before finalizing installation.