Jergens 215-066322 Keylocking Insert 1/4-20 X 3/8-16 Unc

Product Description

The JERGENS 215-066322 is a thin wall keylocking thread locking insert designed to provide a permanent, load-bearing internal thread in metal assemblies. Manufactured from 303 stainless steel with a passivated finish, this insert accepts a 1/4-20 internal thread (Class 2B fit) and installs into a 3/8-16 external thread (Class 2A fit) in the host material. The overall length is 0.37 inches. Keylocking inserts mechanically lock into the parent material using keys that are driven flush after installation, preventing rotation or pullout under vibration and dynamic loads. This insert meets NAS 1394 standards and is suited for precision fastening applications where thread stripping or material weakness is a concern.

This insert is used in applications where a stronger internal thread is needed in softer base materials, thin-walled components, or high-vibration environments. It is commonly installed in aerospace, defense, industrial machinery, and MRO applications. The stainless steel construction and passivated surface treatment make it appropriate for environments where corrosion resistance is required alongside mechanical thread reinforcement. Machinists, assembly technicians, and maintenance professionals typically install these inserts using a drill, tap, and manufacturer-supplied key-driving tool.

Key Features

• 1/4-20 internal thread with Class 2B fit for standard fastener engagement
• 3/8-16 external thread with Class 2A fit for host material installation
• Thin wall keylocking design locks mechanically into parent material to resist rotation and pullout
• 303 stainless steel construction with passivated finish for corrosion resistance
• Meets NAS 1394 standard
• Overall length of 0.37 inches for use in thin-wall or space-constrained assemblies

Compatibility

Designed as an OEM-style replacement or new-installation keylocking thread insert for host materials tapped to a 3/8-16 UNC thread, producing a 1/4-20 UNC internal thread per NAS 1394 requirements.

Installation Notes

Installation requires drilling and tapping the host material to the correct 3/8-16 specification before driving the insert. Power down and secure any machinery before performing thread insert work on live assemblies. Use the appropriate keylocking installation tool to drive the locking keys flush with the host surface after the insert is seated. Do not over-drive the keys, as this can distort the insert or damage the surrounding material.