Mild Steel is an umbrella term that characterises low carbon steel which doesn’t contain and alloying elements and has a carbon content not greater than 0.25%
Mild steel is a widely used metal in many applications. It has good free machining and fabrication properties and can be used in mechanical engineering where the parts will not be subject to high stress.
Mild steel is a ferrous material and is, therefore, has magnetic properties. However, the presence of Iron in its makeup means that if left untreated and exposed to the elements it will corrode/rust fairly quickly, and more so in salty environments.
If using mild steel in your project you may wish to consider painting the surfaces, alternatively, a thin layer of lubricating point will protect moving components within an assembly.