Most tension springs are wound with an initial tension, this tension is the force which holds the spring coils wound together. The measure of initial tension is the load necessary to overcome the internal force to start coil separation.Steel alloys are the most commonly used spring materials. The most popular alloys include high-carbon (such as the music wire used for guitar strings), oil-tempered low-carbon, chrome silicon, chrome vanadium, and stainless steel.
Tension springs are often used in lever-based mechanisms such as garage doors and are one of the most popular spring types. They are frequently used to provide return force to components that extend in an actuated position. Tension springs absorb energy to create a resistance to a pulling force.Animation: Compression springs are designed to absorb forces by squeezing together. Tension springs work the opposite way, stretching apart when you apply a force. Torsion springs have parallel bars on the end that stop something turning (or bring it back to its original position if it does).
There are three classes of springs: