Springs and components that provide reliable deflection are important in so many applications. Without such properties, many systems and products would fail to function. This ranges from small mainspring mechanisms in a watch to torsion springs used in vehicular suspension systems. For as much as springs may vary in terms of size, structure, and performance, there’s a special material that makes all the difference and it’s known as spring steel.
Referring to spring steel as one material is somewhat of a misnomer. Spring steel encompasses a whole family of steel that’s used in the manufacture of springs and components that function in a similar manner. Piano wire, binder clips, and standard wave and metric belleville washers are examples of products made from various grades of spring steel.
Spring steel possesses the unique combination of flexibility and strength, which is achieved through a hardening and tempering process. Spring steel grades are designed to exhibit an exceptionally high-stress point so it will bend rather than break or deform when formed into a spring shape.
As the spring or spring component is deflected, twisted, compressed, or expanded, it will reliably return to form once the force is removed. The most common types of spring steel consist of low-alloy manganese, medium carbon steel, and high carbon steel that’s alloyed to provide high yield strength, which is another way of saying elasticity.
When applications require an SAE or ASTM grades, which is common in automotive placement, there are unique types of spring steel with their own alloy properties and performance specifications. For example, grade 5160 spring steel is also known as chrome-silicon spring steel, which offers extended fatigue resistance, while 301 spring tempered stainless steel provides resistance to corrosion and can be used in external applications without a danger of rust.
There are other grades of steel that can be hardened and treated for use in the production of springs, but the hardening process alone isn’t enough to ensure optimal results. There are some steels that simply provide better spring and deflection characteristics when used to create various components.
When sourcing springs and other parts made from spring steel, always make sure you choose a reputable supplier that can produce all necessary assurances and material certifications.