The service life refers to the number of extractions and retractions that a spring can perform within the working range without breakage.
Most spiral springs are subjected to fatigue stresses. In general, the expected service life is divided into three categories based on the Wöhler diagram: static, finite life fatigue strength and fatigue limit.
As with comparable spring types, the service life of spiral springs is based on the interaction between bending stress, type of load, working temperature, fastening/mounting, material properties and, where applicable, positive influencing factors such as spring supports.
Compared to power springs, which are mainly found in the finite life fatigue strength range, the lesser influence of friction means that spiral springs can achieve a service life of more than 10 million load cycles.