| Antiquity |
Meteoric Steel |
Natural iron-nickel alloy, extremely rare |
Tutankhamun's dagger |
| Ancient Civilizations |
Wootz Steel |
Crucible steel, high-carbon, unique patterns |
Damascus Steel |
| Eastern Han Dynasty |
Forged Steel |
Decarburizing pig iron, forging into steel |
Han-dynasty steel swords, iron tools |
| Early Modern Era |
Blister Steel |
Carburization process, improved strength, low efficiency |
European sabers, spring parts |
| Industrial Era |
Alloy Steel, Stainless Steel, etc. |
Automated steelmaking, controlled carbon/nickel, high-purity alloys |
Structural steel, aerospace parts |