Spring Material Selection
During the spring wire material selection for your compression, extension, or torsion spring, take into notice the following parameters and environmental specifications.
The first thing you must do when designing a spring is measure the space where it shall be installed so that you can set certain tolerances that’ll help your spring’s installation to go smoothly. One very important detail, though, is the environmental requirements your spring must meet.
The most common and economical spring types are Music Wire and Hard Drawn. These types of spring wires are not corrosion-resistant and they don’t tolerate as high temperatures as more extravagant wires do; but these two are able to work in temperatures as high as 250ºF (121ºC). If your spring is not being exposed to any harsh environments, this is your best option.
For corrosive environments where your spring will be exposed to moisture and heat that will cause your spring to rust, you want to use one of the three types of Stainless Steel. There is Stainless Steel 302, Stainless Steel 17-7, and Stainless Steel 316. They are all resistant to moisture but their levels of temperature resistance are different and so are their tensile strengths. In this case you would have to know the maximum temperature that your spring will be undergoing and take it from there to select the perfect Stainless Steel material.
When it comes to springs that are required to be non-magnetic, you can use Stainless Steel 316. This material type isn’t 100% non-magnetic though. Stainless steel 316 is only 90% non-magnetic. If you’re in the testing phase of your project, this is the most economical option but, if you’re in the final production stages, you might want to go with more extravagant material types such as Elgiloy or Beryllium Copper. The properties of these spring materials will work but you must be advised, they are not easy to find and they can be quite expensive. This is why we recommend that you purchase springs made of these materials in larger production quantities.
Most types of metals will produce a spark if friction is produced between the two objects so if you want to avoid this from happening, the spring material type you must use is Beryllium Copper. This material type, besides being non-magnetic, is also non-sparking.