Certain types of stainless steel are specifically designed and processed to be used as spring steel. While not all stainless steel alloys are suitable for springs, those designated as spring temper possess the necessary mechanical properties.

To function effectively as a spring, a material needs:

• High Yield Strength: To resist permanent deformation under load.
• Good Elasticity (High Modulus of Elasticity): To return to its original shape after the load is removed.
• Fatigue Resistance: To withstand repeated cycles of loading and unloading without failure.
• Sufficient Hardness and Tensile Strength: To handle the stresses involved.

Austenitic stainless steels like AISI 302, 304, and 316, as well as precipitation-hardening grades like 17-7PH, can be cold-worked (typically through cold drawing for wire) to achieve these properties. The cold working process significantly increases the tensile and yield strength, making the material suitable for spring manufacturing.

Therefore, while standard annealed stainless steel might be too soft for spring applications, stainless steel in a ‘spring temper’ condition, achieved through cold working, is an excellent choice for springs, especially when corrosion resistance or performance at different temperatures is required.