The metal parts for spring terminal block consist of a current bar and a clamping device. The current bar, at the core of the insulating body, is constructed from copper or brass.
The clamping device fastens the wire in the terminal block and creates a dependable electric connection between the wire and the current carrying bar.
The dimension of these parts varies in regard to the amperage/wire size and the construction of the block itself. Depending upon terminal block layout, wires can be clamped in position using screws, a combination of screws and pressure plates, wire cages or spring clamps. A screw is the easiest method of connection: A screw is utilized to secure the wire against the current bar. With screws and a pressure plate, the wire is constrained with a metallic plate, which fastens the wire when the screw is secured. With a wire cage, when the screw is tightened, a cage pulls upward and squeezes the conductor against the current bar. The large contact area provides exceptional contact properties. Because the screw does not have immediate contact with the conductor, wire damage is prevented. Even thin stranded wire can be connected without the use of additional Ferrules or wire pins.
Spring clamps require a tool to open. The clamp encloses the wire to provide dynamic clamping. This extra holding action endures vibration.