One thing that is essential to mechanical keyboard switches is the spring, which is closely related to the quality of the switch.

The spring is located underneath the switch cap, usually made of stainless steel or other alloys, and is used to provide a reaction force that allows the keys to spring back into place when pressed.

Springs play a role in the compression and rebound of mechanical keyboard switches. A large part of the feel of a mechanical keyboard and the number of times it is used is determined by the springs at the base of the switches. Depending on the length and pressure of the spring, the rebound force, the pressure at the bottom of the switch, and so on, will vary from switch to switch.