Rondella elastica

A spring is an elastic component that stores energy when deformed and returns to its shape when released.

It absorbs shocks, holds a steady force, or returns a part to position — for example cushioning the chassis or holding a valve or clutch part against its seat.

Springs are used in the suspension, brakes, clutch, engine valves, and many mechanisms. The correct spring matches the load, length, and rate specified for its location.