Iron
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 (sometimes referred to as ferrite) 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] Related articles on Designing Buildings
- Aluminium.
- Cast iron.
- Conservation of Architectural Ironwork.
- Copper.
- Difference between cast iron and wrought iron.
- Failure of cast iron beams.
- Ferricrete.
- Ferrous.
- Iron frames in textile mills.
- Iron ore tailings IOTs.
- Ironwork.
- Metal.
- Pearlite.
- Steel.
- The Iron Bridge.
- The iron roof at the Albert Dock.
- Types of metal.
- Types of steel.
- Wrought iron.
- Zinc
Featured articles
Check out some of the best features and news from Designing Buildings as well as key stories from around the web.
National Scheme of Delegation introduced.
The cost of employing people remains a concern.
Code of Practice for Electrical Energy Storage Systems.
ECA calls on members to comment on draft 4th edition.
Bringing together expertise and creating cultural benefits.
CIOB celebrates positive Ofsted report.
The Building Safety Regulator announces a call for evidence.
Government approach could undermine delivery and regeneration.
World's first mass timber data centre.
The overlooked environmental aspect of data centre development.
Introduction to radon awareness
New technical information sheet published by CIOB.
Updated supplier guide can help electrical contractors engage with NHP.
CIAT confirm the winners of the 2026 architectural technology awards.
Government launches a one stop shop for flood preparedness.
















