Screw terminal

Screw terminals are commonly used to connect a chassis ground, such as on a record player or surge protector.

Grounding screws are often color-coded green and, when used on consumer electronics, often have a washer with gripping "teeth", to ensure better connections.

Some designs provide features that allow the flow of molten solder to ensure a better connection between the circuit traces of the board and the electrical equipment which is meant to be controlled or fed appropriate power.

While wires may be crimped, they should not be heavily tinned with solder prior to installation in a screw terminal, since the soft metal will cold flow, resulting in a loose connection and possible fire hazard.

The terminals easily can be re-used in the field, allowing for the replacement of wires or equipment, generally with standard hand tools.

Screw terminals usually avoid the requirement for a specialized mating connector to be applied to the ends of wires.

When properly tightened, the connections are physically and electrically secure because they firmly contact a large section of wire.

The use of screw terminal "chocolate blocks" in building wiring installations has sharply declined in favour of crimp, push, and twist type connectors which are and easier to fit, and less vulnerable to working loose.

Screw terminals, as individual connectors to a board at left, as a barrier strip with setscrews at top, and as a barrier strip with attached spade and loop lugs at bottom.
Two paired screw terminals, typically used for connecting ceiling-mounted light fixtures
Barrier strip
Two types of screw terminals showing a significant development in design. Basic, with the wires held between the screw heads and the terminals (left) and with the wires held, reversely, between the metal clamping plates and the rear of the terminals (right).