What component do back-wire devices use that is threaded onto the terminal screw?

Back-wire devices utilize a clamping plate that is threaded onto the terminal screw. This design facilitates a secure electrical connection while allowing for quicker installation. When wires are inserted into a back-wire device, the clamping plate ensures that the wire is held tightly against the terminal, promoting good conductivity and minimizing the risk of loose connections, which can lead to electrical failure or hazards.

The clamping mechanism is essential for maintaining reliable performance over time, as it accommodates the thermal expansion and contraction of the wires. This feature is particularly important in electrical installations where safety and longevity of the electrical connection are paramount. The threading of the clamping plate onto the terminal screw also allows for easy adjustments during installation, ensuring that the technician can create a strong, dependable connection with minimal effort.