E-z Lok 335-5 Thread Locking Insert 5/16-18 Unc

Product Description

The E-Z LOK 335-5 is a self-locking threaded insert designed to create a secure, vibration-resistant internal thread in metal assemblies. It features a 5/16-18 internal thread and a 9/16-12 external thread, both to UNC standards, with an overall length of 0.515 inches (33/64 inches). Manufactured from C12L14 carbon steel with a smooth rolled finish, this insert is installed into a pre-tapped hole and relies on its self-lock wall design to resist loosening under load or vibration. It is a standard choice for maintenance, repair, and original equipment manufacturing applications where thread integrity is critical.

This insert is suited for use in ferrous and non-ferrous metal components where a reliable UNC internal thread must be established or restored. The self-lock wall design makes it appropriate for assemblies subject to dynamic loads, torque cycling, or vibration. It is installed using a standard tap corresponding to the 9/16-12 external thread, making it compatible with conventional shop tooling. Typical users include machine shops, maintenance technicians, and field service professionals working on industrial, mechanical, and structural assemblies.

Key Features

• 5/16-18 internal thread and 9/16-12 external thread, both UNC standard
• Self-lock wall design resists loosening under vibration and dynamic loading
• C12L14 carbon steel construction with smooth rolled finish
• Tensile strength rated at 10,215 pounds
• Overall length of 0.515 inches (33/64 inches) for compact fitment
• Installs with a standard tap - no special driver required for the external thread preparation

Compatibility

Designed as an OEM-style replacement or repair insert for metal assemblies requiring a 5/16-18 UNC internal thread established via a 9/16-12 UNC tapped hole using a standard tap.

Installation Notes

Installation should be performed by a qualified machinist or mechanical technician. Before installation, ensure the host material is tapped to the correct 9/16-12 UNC specification using a standard tap as specified by the manufacturer. Secure the workpiece and de-energize or lock out any associated equipment before performing thread repair or insert installation. Do not exceed the rated tensile load during assembly or service.