Install these lugs in outdoor utilities, public buildings, and anywhere else you need to leave your installation unmonitored. Use an L-key to tighten the set screws onto the wire. When you apply enough torque, the screw heads shear off so the connection can’t be removed or altered.

Set screw lugs attach to even larger wire than compression lugs, such as the 1000 MCM building wire used in large factories. They're also easier to install and reusable because you cinch the wire with a set screw rather than crushing the barrel. They don't hold the wire as securely as compression lugs, however—use them when pulling and bending aren't a concern and you need to easily break your connection for maintenance or adjustments.