screwterminal

A screw terminal is a type of electrical connector that uses a screw to clamp a conductor and make an electrical connection. The conductor is placed under a metal clamp and tightened with the screw, creating contact with a conductive path inside an insulated housing. Screw terminals are widely used in terminal blocks and terminal strips, and they appear in single- or multi-position formats, including PCB-mounted versions.

Construction and variants: The contact is formed by a metal clamp attached to a conductor path, typically inside a plastic or phenolic body that provides insulation and mounting features. Conductors enter from the top or side, and are commonly solid or stranded wires. Stranded conductors are often terminated with ferrules to improve reliability. Variants include through-hole PCB screw terminals, right-angle PCB terminals, and barrier or strip-type terminal blocks for field wiring.

Electrical characteristics and wiring: Screw terminals are rated by voltage and current, with common values spanning several hundred volts and a range of amperes depending on size. They accommodate a variety of conductor sizes, and tightening torque specifications are important to maintain a reliable connection. Proper stripping length and secure fastening are essential to prevent arcing or loosening.

Applications and considerations: They are used in power supplies, control panels, audio equipment, consumer electronics, and general prototyping. Advantages include simplicity, low cost, and robustness. Limitations include potential loosening under vibration and the need for periodic retightening in some installations. For high-vibration or high-current applications, locking screws or alternative connectors may be preferred.