Stainless steel springs are made from a special kind of steel that is resistant to rusting. This is where the “stainless” part comes in. The metal keeps its shiny appearance in most types of conditions. You can usually find this steel in the home as most kitchen knife blades as well as cutlery and other kitchen utensils are made to resist the effects of rust.
Steel is what the ancient people of the Iron Age really wanted to get their hands on – even if they didn’t know it. It could be described as iron on steroids in a way, as it greatly enhances the natural mineral. Basically, it is a simple alloy with a composition made up mainly of iron with a small percentage of carbon. While it depends on the particular grade of steel, the carbon percentage can be between 0.2% and 2.1% as measured by weight.
There are other elements added to iron to produce steel. They include manganese, vanadium, tungsten and chromium. It is the latter that that holds the key to making stainless steel springs, for when a minimum of 12% of chromium is added to the steel making process, you produce a metal that is highly resistant to oxidation and the characteristic reddish brown rust stains. Nickel is also added to the mix at about 8%.
Stainless steel springs have a number of advantages compared to those made of carbon steel. Their resistance to corrosion is undoubtedly the most important. It isn’t only rusting they are resistant to, however. They are resistant to corrosion and damage from a variety of chemicals, which makes them very suitable for use within mechanised plant in the food processing industry, as well as in the medical industry and in many marine environments.
The use of austenitic stainless steel springs allows them to be operational in relatively high temperatures. This is a steel that can operate in temperatures up to 344 degrees Celsius. Springs made of oil tempered steel can only work in high temperatures of up to about 121 degrees Celsius. This makes it a steel spring with much greater versatility, and therefore greater practical uses too. Austenitic stainless springs can’t be hardened through heat treatment, but they can develop high tensile strength through cold drawing of the wire.