Steels are alloys that have iron content ranging from more than 99 percent to less than 60 percent, with carbon and other metallic elements to harden the alloys or give them other properties. Iron by itself is relatively soft and prone to rusting. Steel is hard and corrosion-resistant.
Alloy steels have a little carbon but mainly have other metals to give them various properties, such as strength from nickel, corrosion resistance from chromium, toughness from vanadium, hardness from manganese, improved wear from molybdenum and high-temperature strength from tungsten.
Other types are carbon steel with 1 to 2 percent carbon, the most widely used; galvanized steel, which is zinc-coated; electroplated steel coated with tin in a process using electrical current; tool steel made under high temperatures and cooled quickly to make it hard; and the ancient Damascus steel of very high quality.