Based on the percentage of carbon content carbon steel is categorized in to 4 main types - low carbon steel (0.05–0.26% carbon), medium carbon steel (0.29–0.55% carbon), high carbon steel (0.55–1% carbon), and very high carbon steel (1–2.10% carbon). Carbon percent increases the toughness of the steel.
Low Carbon Steel (Mild Steel) typically contains 0.05% to 0.26% carbon content. This is one of the largest categories of Carbon Steel. It covers a variety of shapes, from Flat Sheet to Structural Beam. Depending on the required properties, other elements are upgraded and fostered. For e.g. In Drawing quality steel,the carbon level is very low and Aluminum is added, and for Structural Steel the carbon level is comparatively higher and the manganese content is increased.
Medium Carbon Steel has a carbon range of 0.29% to 0.55%, and a manganese content ranging from 0.060% to 1.65%. This steel is stronger than low carbon steel and it is more difficult to mould, weld and cut. Medium carbon steel is quite often hardened and tempered using heat treatment. It is used for manufacturing large metal structures and automotive components.
High Carbon Steel is commonly known as ‘carbon tool steel’ has a carbon content between 0.55% and 1.0%. High carbon steel is very difficult to cut, bend and bind. Once it has undergone heat treatment it becomes very hard and brittle. It is very strong and holds shape memory as well. It is commonly used to manufacture high strength springs and wires.
Very High Carbon Steel has a composition of 0.96%-2.1% carbon. Its very high carbon content makes it an extremely strong and tough material. Due to its high brittleness and fragile nature, very high carbon steel requires special handling.