Wave spring

A wave spring, also known as "coiled wave spring" or "scrowave spring", is a spring made up of pre-hardened flat wire in a process called "on-edge coiling" (also known as edge-winding). During this process, waves are added to give it a spring effect. The number of turns and waves can be easily adjusted to accommodate stronger force or meet specific requirements.
Advantages.
A wave spring has advantages over a traditional coiled spring or a washer:
Varieties.
Multiple types of wave spring are available: Single-turn wave springs include gap single-turn and overlap single-turn type. Multi-turn wave spring types, include shim-end and plain-end types. The nested wave spring incorporates smaller waves within larger ones.
Single-turn wave spring.
Single-turns are best for applications with short deflection and low to medium forces. The number of waves and material thickness can be changed to accommodate stronger forces. It is used for bearing pre-load.
Multi-turn wave spring.
A multi-turn wave spring can decrease the needed axial space. It is suited for applications with large deflection and a small spring rate. A wide range of forces can be accommodated.
Nested wave spring.
Eliminates the need to stack springs to accommodate higher loads. It produces high force while maintaining the precision of a circular-grain wave spring. It replaces a stack of belleville washers where a high but accurate force is needed.