Last edited 07 Feb 2018


Iron is the chemical element most commonly found on Earth by mass, forming much of the Earth’s outer and inner core. On the Periodic Table it has the symbol ‘Fe’ and atomic number 26.

Pure iron is relatively soft but it is significantly hardened and strengthened during the smelting process by impurities such as carbon. Pig iron, with a high carbon content (3.8-4.7%) is produced in a blast furnace by heating iron ore with limestone and coke. Steel is produced by further refining pig iron with oxygen, reducing the carbon content to 0.04-1.5%. Steel can be up to 1,000 times harder than pure iron. Carbon steel is typically classified as low, medium, or high carbon steel.

For more information see: Steel.

Wrought iron is a very low carbon metal, historically made by intensive hand work using small scale production methods. Confusingly, the term 'wrought iron' can also be applied to decorative hand made steel artefacts as 'wrought' means to make by hand (to wrought).

For more information see: Wrought iron.

The term 'cast iron' refers to a range of iron-carbon alloys, with a carbon content that is typically between 2 and 4%. During the Industrial Revolution, before the widespread development of the steel industry, cast iron was commonly used in a wide range of architectural applications because of to its relative affordability.

For more information see: Cast iron.

As iron-bearing rock is plentiful, steel and iron alloys are very popular industrial and construction materials.

[edit] Find out more

[edit] Related articles on Designing Buildings Wiki