"Standard" spring steel comes in several grades. At Roveron, Class-C spring steel is the most commonly used standard wire grade.
The table below shows the applications for wire and sheet steel and then the desired heat treatments to have optimum springs in the desired conditions.
For leaf springs, C75 is the most common "ordinary" steel grade. In practice, however, this is a type of material, which will crack very often under the influence of buiding. We often advise our customers to choose stainless steel spring band steel.