Spring steels have rather high carbon content, 0.5 – 0.6%, and high strength, hardness and resistance to fatigue can be achieved through heat treatment. The elevated yield strength favours good spring properties permitting repeated storage and recovery of elastic energy.

As the name would suggest, the main area of application for these materials is in fact springs. However, the high hardness also renders them suitable for tools and some machine and wear parts. The steels available from stock are in hot-rolled or annealed execution for ease of processing but will need to be heat treated in order to attain the desired high levels of strength and hardness.