Alloy steels were known from antiquity, being nickel-rich iron from meteorites hot-worked into useful products. In a modern sense, alloy steels have been made since the invention of furnaces capable of melting iron, into which other metals could be thrown and mixed.

Historic types

* Damascus steel, which was famous in ancient times for its durability and ability to hold an edge, was created from a number of different materials (some only in traces), essentially a complicated alloy with iron as main component.
* Blister steel - steel produced by the cementation process
* Crucible steel - steel produced by Benjamin Huntsman's crucible technique
* Styrian Steel, also called 'German steel' or 'Cullen steel' (being traded through Cologne) was made in Styria in Austria by fining cast iron from certain manganese-rich ores.
* Shear steel was blister steel that was broken up, faggotted, heated and welded to produce a more homogeneous product.

Contemporary Steel

* Carbon steel, of which mild steel is one type.
* Stainless steels and surgical stainless steels contain a minimum of 10.5% chromium, often combined with nickel, to resist corrosion (rust). Some stainless steels are nonmagnetic.
* Tool steels
* HSLA steel (high strength, low alloy)
* Advanced High Strength Steels
o Complex Phase Steel
o Dual Phase Steel
o TRIP steel
o TWIP steel
o Maraging steel
* Ferrous superalloys
* Hatfield steel or Manganese steel, this contains 12-14% manganese which when abraded forms an incredibly hard skin which resists wearing. Some examples are tank tracks, bulldozer blade edges and cutting blades on the jaws of life.

Though not an alloy, there exists also galvanized steel, which is steel that has gone through the chemical process of being hot-dipped or electroplated in zinc for protection against rust. Finished steel is steel that can be sold without further work or treatment.

Production methods

* Crucible technique - the original steel making technique, developed in India as wootz, used in the Middle East as Damascus steel.
* Cementation process used to convert bars of wrought iron into blister steel. This was the main process used in England from the early 17th century.
* The more recent version of the crucible technique was independently redeveloped in Sheffield by Benjamin Huntsman in c.1740, and Pavel Anosov in Russia in 1837. Huntsman's raw material was blister steel.
* Bessemer process, the first large-scale steel production process for mild steel.
* Puddling
* The Siemens-Martin process, using an Open hearth furnace
* Basic oxygen steelmaking
* Electric arc furnace a form of secondary steelmaking from scrap, though the process can also use direct-reduced iron