1. Low carbon steel Mild steel has a carbon content of 0.04-0.3% and is the most common grade of carbon steel. Mild steel is also considered mild steel as it is defined as having a low carbon content of 0.05-0.25%. Mild steel is ductile, highly malleable and can be used in automotive body parts, sheet and wire products. At the high end of the low carbon content range, plus up to 1.5% manganese, the mechanical properties are suitable for stampings, forgings, seamless tubes and boiler plates. 2. Medium carbon steel Medium carbon steels have a carbon content in the range of 0.31-0.6% and a manganese content in the range of 0.6-1.65%. This steel can be heat treated and quenched to further tune the microstructure and mechanical properties. Popular applications include axles, axles, gears, rails and railroad wheels. 3. High carbon steel High carbon steel has a carbon content of 0.6-1% and a manganese content of 0.3-0.9%. The properties of high carbon steel make it suitable for use as springs and high strength wire. These products cannot be welded unless a detailed heat treatment procedure is included in the welding procedure. High carbon steel is used for cutting tools, high strength wire and springs.