pile of springs

One of the innate characteristics of most metals is the ability to “spring” back to its original state when bent of contorted. This “springiness” is what makes many metals the ideal materials for springs and custom wire forms. But what gives metal this unique ability, and what makes it the ideal material to be used? While there are certain chemical and atomic processes going on inside wire materials, which we won’t dive into for the purpose of simplicity, there are a few simple ways to explain what gives a wire its spring.

What Gives a Wire its Spring?

Spring materials will naturally bounce back when bent or contorted, but bend them too far and they cannot recover. This is partially determined by its tensile strength. The strength of the metal can be increased through cold-working, which is also following by stress-relieving and aging processes. Through the cold-working and annealing processes, the tensile strength of the metals will increase without reducing the diameter of the wire.

As the wire goes through multiple cold-working and annealing cycles, the grain sizes of the metals are reduced, resulting in a higher tensile strength. This allows the metal to become more resistant to breaking when stress is applied to it. This is particularly important for springs that will have large loads applied to them.

Yield Strength is Also Important

The second factor that gives a spring its abilities is its yield strength, which determines the stress at which a specific amount of deformation is produced. Yield strength is usually taken as 0.2 percent of the unstressed length. When a metal wire is pushed beyond its yield strength, it will not recover and will become permanently deformed. Essentially, the material will not spring back.

It All Depends on the Wire

This was a rudimentary look at what gives a spring its spring, but other factors can come into play, as well. It all depends on the type of wire used and what metals the wire is made out of.

The tensile strength of some metals, for example, can be increased through quenching and tempering rather than by being cold-worked. At The Yost Superior Co., we work with many types of wires to make our spring and wire forms. We can help you determine which type of wire is best suited for your application, so do not hesitate to reach out to us and ask for help when designing your spring. Our qualified engineers will be glad to offer you any assistance that you need.

Get in touch with us today to find out more about how we can fulfill your custom spring and wire form needs.