A variety of questions must be asked and answered to arrive at the best spring material including:
The environment in which the product operates;
The frequency of cycles and the amount of deflection;
The ratio of spring or wire form cost in relation to the overall project;
The expected life of the product.
Some springs are used in products that are discarded in a relatively short time frame and have a low cycle frequency during that time. In those cases, the design should specify a general-purpose spring wire, which can keep costs down while not affecting product performance.
Conversely, stainless steel is often specified in products frequently exposed to moisture. Other spring materials include Hastalloy C-276 alloy (for use in highly corrosive atmospheres), music wire (which is a carbon steel and has the best resilience to being deflected and distorted), chrome silicon, copper, aluminium, phosphorous bronze and so on.