The clamping function of high-temperature springs

High-temperature springs are found throughout the spring family, and their most important characteristic is the clamping function. In different applications the spring is used in different ways, but the purpose is the same: to hold two parts firmly together. Many household appliances use high-temperature springs, especially in electrical switches, where a spring between the two switch contacts keeps them in firm contact and ensures good conductivity.

Why clamping force matters

If the clamping function of the high-temperature spring fails, the switch contacts no longer touch properly. Contact resistance rises, heat is generated as current passes, and in severe cases the contact metal can melt.

Where the clamping function is used

Electric lamps. The bayonet cap of a lamp uses a high-temperature spring to hold the two metal contacts in firm contact. In the screw-base lamp and in sockets, the centre contact and the socket contacts are spring-loaded metal pieces whose job is to keep the two sides firmly in contact.

Staplers. A long spring in a stapler pushes the staples forward; as each staple is fired, the spring advances the next one, continuing until the last staple has been used.

Tape recorders. A phosphor bronze reed acts as a leaf spring; its bending deformation creates the force that presses the magnetic head into close contact with the tape.

Clips and pens. Clothes clips, ballpoint pens and pen clips all rely on the clamping function of a small spring.