E-z Lok 319-4 Thread Locking Insert 1/4-20 X 3/8-16 Unc

Product Description

The E-Z LOK 319-4 is a self-lock wall thread locking insert designed to create a secure, load-bearing threaded connection in parent materials that require a different internal thread size than the host bore. The external thread is 3/8-16 UNC and the internal thread is 1/4-20 UNC, with an overall length of 0.375 inches. Manufactured from C12L14 carbon steel with a smooth, rolled finish, this insert delivers a tensile strength of 5,315 pounds. It installs using a standard tap and is suited for applications where vibration resistance and thread integrity are critical.

This insert is used in metal fabrication, equipment assembly, and maintenance repair operations where a threaded hole must be downsized, reinforced, or converted from one thread size to another. The self-lock wall design resists loosening under vibration and dynamic loads without requiring thread-locking adhesives. Typical applications include industrial machinery, structural assemblies, and custom fabricated components where UNC thread standards are specified. Licensed tradespeople and skilled assemblers in HVAC, mechanical, and general fabrication settings routinely use these inserts during equipment builds and field repairs.

Key Features

• 1/4-20 UNC internal thread with Class 2B fit for standard fastener compatibility
• 3/8-16 UNC external thread with Class 2A fit for consistent host-bore engagement
• Self-lock wall design resists back-out under vibration without adhesives
• C12L14 carbon steel construction rated to 5,315 pounds tensile strength
• 0.375 inches overall length for low-profile installation in thin-wall applications
• Smooth, rolled finish for clean thread engagement and consistent installation torque

Compatibility

Designed for use with standard UNC taps in parent materials bored to accept a 3/8-16 external thread; compatible with any 1/4-20 UNC fastener meeting Class 2B fit requirements.

Installation Notes

Installation is performed by licensed tradespeople or trained assemblers using a standard tap sized for the 3/8-16 external thread. Ensure the parent material bore is properly tapped and free of debris before driving the insert. Power down or de-energize any equipment before servicing threaded connections on live assemblies. Follow applicable torque and fastener specifications for the host application per relevant industry standards.