E-z Lok 319-428 Thread Locking Insert 1/4-28 X 3/8-16 Unf

Product Description

The E-Z LOK 319-428 is a self-lock wall thread locking insert designed to create a secure, threaded connection in a host material. It features a 1/4-28 UNF internal thread with a 2B class of fit and a 3/8-16 UNF external thread with a 2A class of fit. The insert measures 0.375 inches in overall length and is machined from C12L14 carbon steel with a smooth, rolled finish. It installs using a standard tap, making it compatible with common shop and field tooling. Machinists, maintenance technicians, and assembly professionals use this type of insert to restore or reinforce threaded connections in metal components.

This insert is suited for applications where a fine-pitch internal thread must be retained in a coarser or larger-diameter tapped hole. The self-lock wall design resists loosening under vibration and dynamic loading, which makes it appropriate for mechanical assemblies, industrial equipment, and structural fastening applications. The carbon steel construction handles moderate load and wear conditions typical of production and MRO environments.

Key Features

• 1/4-28 UNF internal thread with 2B class of fit for precise mating
• 3/8-16 UNF external thread with 2A class of fit for host material installation
• Self-lock wall design resists loosening under vibration
• C12L14 carbon steel construction with smooth, rolled finish
• 0.375 inches overall length for compact installation envelope
• Compatible with standard tap tooling - no specialty driver required

Compatibility

Designed as a standard UNF thread locking insert for use in metal host materials tapped to accept a 3/8-16 external thread, delivering a finished 1/4-28 internal thread.

Installation Notes

Installation is typically performed by a machinist or maintenance technician using a standard tap to prepare the host material before driving the insert. Ensure the host material is properly fixtured and that the tapped hole meets the required thread tolerance before installation. Degrease the installation area to promote proper seating and locking performance. Follow applicable fastener torque guidelines from the assembly specification - do not exceed the load rating of the host material.