Carbon steel is broadly described as any steel that is not stainless and includes a wide array of alloy steels that probably make it the most commonly used metal-based material. Increasing carbon content (up to a maximum of 2.1% by weight) yields harder and stronger alloys (but with reducing levels of ductility) from the process of heat treatment. Carbon steel can be used in its natural (uncoated) form or coated to enhance its properties (see coated steel section).
Relatively low-cost, carbon steel can be used in many applications where more expensive solutions are not viable. The material is available in a huge range of grades and with different tempers to produce soft (annealed) meshes or more rigid (spring) structures.
Carbon steel is often used in high strength/temperature applications where durability is required but where corrosion resistance is a less significant issue. Galvanic coatings can be applied in applications where the required life-cycle is shorter than a stainless steel alternative eg disposable filter media.