E-z Lok 329-004 Thread Locking Insert 4-40 X 10-32 Unc

Product Description

The E-Z LOK 329-004 is a self-locking threaded insert designed to create a secure 4-40 internal thread in a 10-32 tapped hole. Machined from C12L14 carbon steel with a smooth, rolled finish, this insert measures 0.25 inches in overall length and meets UNC thread standards. It is classified with a 2B internal thread fit and a 2A external thread fit, which provides controlled engagement and reliable resistance to loosening under vibration or cyclic load. The 329-004 is installed by licensed machinists, assembly technicians, and maintenance professionals working with metal substrates where thread repair or thread size conversion is required.

This insert is suited for applications in light manufacturing, maintenance and repair operations, and precision assembly where a 4-40 internal thread must be introduced into a 10-32 parent thread. The self-lock wall design eliminates the need for adhesives or secondary locking hardware in most standard fastening scenarios. Typical installation substrates include steel and aluminum components found in industrial equipment, electronic enclosures, and mechanical assemblies. A standard tap compatible with a 10-32 thread is required to prepare the host material before installation.

Key Features

• 4-40 internal thread provides a smaller-diameter fastener interface in a 10-32 tapped hole
• Self-lock wall design resists rotation and loosening without adhesives
• C12L14 carbon steel construction for strength and machinability
• 0.25 inches overall length suits thin-section and compact assemblies
• UNC thread standard with 2B internal and 2A external class of fit for controlled engagement
• Smooth, rolled finish on external threads for consistent installation torque

Compatibility

Designed for installation into a standard 10-32 UNC tapped hole using a standard tap. Compatible with host materials that can accept a 10-32 external thread engagement.

Installation Notes

Installation is typically performed by machinists or assembly technicians using standard hand or power tools. The host material must be tapped to 10-32 UNC specification before the insert is driven or pressed into place. Ensure the workpiece is fully secured and depowered if the assembly is part of an active system before beginning thread repair or conversion work. Do not exceed the designed class-of-fit engagement by forcing the insert into an undersized or damaged thread.