Steelmaking is the second step in producing steel from iron ore. In this stage, impurities such as sulfur, phosphorus, and excess carbon are removed from the raw iron, and alloying elements such as manganese, nickel, chromium and vanadium are added to produce the exact steel required.

The earliest means of producing steel was in a bloomery. Early modern methods of producing steel were often labour-intensive and highly skilled arts. See:

An important aspect of the industrial revolution was the development of large-scale methods of producing forgeable metal (bar iron or steel). The puddling furnace was initially a means of producing wrought iron, but was later applied to steel production.

The real revolution in steelmaking only began at the end of the 1850s. The Bessemer process was the first successful method of steelmaking in quantity, followed by the open hearth furnace.

Modern steelmaking processes are broken into two categories: primary and secondary steelmaking. Primary steelmaking uses mostly new iron as the feedstock, usually from a blast furnace. Secondary steelmaking uses scrap steel as the primary raw material. Gases created during the production of steel can be used as a source of power.