Southwire LNS400 Steel Locknut 4 Inch

Product Description

The SOUTHWIRE LNS400 is a 4-inch steel locknut designed to secure conduit fittings and connectors to electrical enclosures, junction boxes, and panel knockouts. This hardware provides a reliable mechanical connection that keeps conduit runs stable and prevents loosening from vibration or movement. Electricians install this locknut during conduit system assembly to ensure code-compliant, secure attachment points. The steel construction delivers the strength and durability required for both rough-in and finish electrical work in a wide range of commercial and residential installations.

The LNS400 is suited for use with 4-inch conduit connectors and fittings in standard electrical installations. It applies wherever a conduit run terminates at a box, enclosure, or panel, making it a common part on commercial electrical jobs, industrial installations, and residential service work. Electricians keep these on hand for both new construction and retrofit projects where conduit must be secured to metallic enclosures.

Key Features

• Steel construction for strength and durability in demanding electrical installations
• 4-inch trade size fits standard 4-inch conduit connectors and fittings
• Manufactured in the United States
• One-year limited warranty

Compatibility

Designed as an OEM-style replacement and standard-fit locknut for 4-inch conduit fittings and connectors used with metallic electrical enclosures and junction boxes.

Installation Notes

Installation is performed by a licensed electrician following applicable NEC requirements. De-energize and lock out the panel or enclosure before beginning work on any conduit connection. Thread the locknut onto the conduit connector and tighten firmly against the enclosure wall using a screwdriver or locknut wrench to ensure a secure, low-resistance bond. Do not overtighten in a way that distorts the enclosure knockout.