Fatigue Life in Springs
Springs that are used in consistently performing applications for long periods of time must be checked frequently for fatigue. Although buying quality springs will increase their life expectancy, no springs will last forever. Those springs that do last and continue to perform well will be high in tensile strength and spring fatigue.
What is Spring Fatigue
Spring fatigue is an issue springs face when subjected to cyclic loading, the repeated application of stress and loads to a material’s structural components. For parts like compression springs, this would mean an application where varied or consistent loads are applied to them, causing them to compress and recover, repeatedly across their lifespan. For springs used in manufacturing, spring fatigue is essential because of the redundancy of the application in which the springs are used.
How Does Spring Fatigue Set in?
When a load is applied to a spring, the metal deflects. If it deflects within its range of elasticity, it will return to its normal position (or spring back). If the load exceeds the springs maximum deflection, the material will be put under stress. This can lead to small cracks forming in the spring material, increasing its fatigue. Spring manufacturers use the moment spring fatigue sets in as a test to determine the maximum load a spring can handle at any given time.
Increasing Spring Fatigue
A spring’s maximum fatigue can be increased in multiple ways:
- Increasing the wire’s outer diameter
- Decreasing the wire’s diameter
- Increasing the amount of active coils the spring has
These adjustments can be made during the manufacturing and design process in order to increase the amount of fatigue your spring can handle once it has exceeded its maximum deflection.
Request a Quote
If spring fatigue, tensile strength, or any other factors are important in your custom springs, let us know when you request a quote from our team. We have the capability to accommodate nearly any manufacturing and design request. Have questions about your spring design? Contact The Yost Superior Co. today.