Metal Profile: All About Steel

Worker in a steel shop
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Steel, the world's foremost construction material, is an iron alloy that contains between 0.2 and 2 percent carbon by weight.


The advent of commercial steel production in the late 19th century was a result of Sir Henry Bessemer's creation of an efficient way to lower the carbon content in cast iron. By lowering the amount of carbon in iron to about 2%, the harder and more malleable steel is produced.


Today, most steel is produced by basic oxygen methods (also known as basic oxygen steelmaking or BOS). BOS is so-named because it requires oxygen to be blown into large vessels containing molten iron and scrap steel.

Although BOS accounts for the largest share of global steel production, the use of electric arc furnaces (EAF) has been growing since the early 20th century and now accounts for about one-third of all steel production.


Over 3,500 different grades of steel exist. Commercial steel is generally classified into four groups depending on their metal alloy content and end-use applications:

  1. Carbon Steels (including low carbon, medium carbon, and high carbon steels)
  2. Alloy Steels (common alloy metals; manganese, silicon, nickel, and chromium)
  3. Stainless Steels (contain about 10% chromium and classified as austenitic, ferritic and martensitic)
  4. Tool Steels (alloyed with high temperature and hard metals, such as molybdenum and tungsten)

    Steel has a wide range of alloy compositions, which allow it to have diverse mechanical properties.


    Different types of steel are produced according to the properties required for their application, and various grading systems are used to distinguish steels based on these properties. The following table lists the properties of steels at room temperature (25°C).


    From stainless and high-temperature steels to flat carbon products, steel's various forms and alloys offer different properties to meet a wide range of applications. For these reasons, as well as the metal's combination of high strength and a relatively low production cost, steel is now used in countless products.

    Steel applications can be divided into five sectors.