A screw terminal is a type of electrical connector where a wire is clamped down to metal by a screw. The wire is sometimes just stripped of electrical insulation at the end, and is bent in a U or J shape to fit around the shaft of the screw. Alternatively, a lug can be crimped onto the end of the wire to protect it. Setscrews are also used, as in a luster terminal or lustre terminal, but lugs will not fit into them. For both lugs and bare wire, the screw is tightened for a secure connection.
