What a locknut does
When a cable connector or conduit fitting goes into an electrical box, it passes through a knockout from the outside and its threaded end sticks into the box. The locknut threads onto that end and is tightened against the inside wall of the box, locking the fitting in place. Without it, the connector can rotate, work loose over time and leave the cable or conduit unsupported right where it matters most. The ED-LNS-S050 is a 1/2 in steel locknut sold in a bag of 10, made for residential and commercial projects.
Compatible fittings and boxes
Match the locknut to the size of the fitting: this one is for 1/2 in threaded ends. That covers a wide range of everyday hardware: 1/2 in cable connectors, EMT set-screw and compression connectors, flexible metal conduit connectors, liquid-tight fittings and threaded rigid conduit. It is used with metal device boxes, octagon and square boxes, junction boxes, panel and disconnect enclosures, and any equipment with a 1/2 in knockout. Many connectors come with their own locknut, but those tend to vanish into wall cavities and sawdust; a spare bag keeps the job moving.
Installation tips
Turn the power off at the panel before working in any box. Remove the 1/2 in knockout, push the connector through from the outside and secure the cable or conduit to it. Thread the steel locknut onto the connector by hand inside the box, then snug it firmly against the box wall with a flat screwdriver or pliers until the fitting no longer turns. Check that it is tight before pulling the conductors. For anything beyond a simple replacement, have the work done or verified by a licensed electrician, in line with the electrical code that applies in your province.
Product details
Model: ED-LNS-S050
Product: locknut
Material: steel
Size: 1/2 in
Package: bag of 10
Applications: residential and commercial electrical projects
Documentation: PDF in the Documentation tab
Everyday applications
Picture an electrician running EMT along a garage wall to a new workbench receptacle, a renovator installing pot lights and switch boxes in a finished basement, or a maintenance team replacing a damaged liquid-tight fitting on a heat pump disconnect. In each case, the 1/2 in locknut is the part that holds the fitting firmly against the box, and having a full bag on hand means no job waits for one missing piece. The manufacturer's PDF document is available in the Documentation tab for reference.
