Steel Mills (Manufacturing)" is a subdivision of the SIC Code 3312, which includes companies involved in the production of steel through the process of melting, refining, and casting. The steel produced by these mills is used in a wide range of industries, including construction, automotive, and manufacturing. The process of steel production involves the use of raw materials such as iron ore, coal, and limestone, which are melted in a blast furnace to produce molten iron. The molten iron is then refined to remove impurities and alloyed with other metals to produce the desired steel grade. The steel is then cast into various shapes and sizes, including bars, sheets, and coils, which are sold to customers for further processing or use in their products. Steel mills are typically large-scale operations that require significant capital investment and specialized equipment to operate efficiently.