The exact time of the invention of steel remains uncertain among researchers, but some of the earliest examples of steel date back to the 1st millennium BC in Central Asia and South Asia.
Steel is a cornerstone of the modern world, used in the construction of skyscrapers, automobile manufacturing, and many other fields. However, steel is not found naturally. This robust modern metal has origins that date back at least 2,000 years, although archaeologists are unable to pinpoint the exact timeline of its emergence, according to Live Science.
Steel is primarily made of iron with a small amount of carbon to make it harder. (Photo: Monty Rakusen).
Steel is an alloy of iron and carbon. While mainly composed of iron, the addition of 0.2 – 1% carbon enhances steel’s hardness, durability, and resistance to rust compared to pure iron. Archaeologists believe this improvement was independently discovered in several locations, later spreading throughout the ancient world. “Steel was developed throughout the 1st millennium BC in the Old World,” said Paul Craddock, an expert in ancient metallurgy at the British Museum.
Some of the earliest examples include forged steel, produced by melting iron and carbon together in various locations across Central Asia and South Asia. Other primitive forms of iron production contained enough carbon to be classified as steel. However, during Roman times, artifacts such as Roman daggers were crafted from fully heat-treated steel. This required advanced forging techniques, heating, and hammering cast iron to remove impurities before adding a small amount of carbon. Experts are unsure who first devised such techniques, but it necessitated melting iron at very high temperatures to avoid impurities when using iron ore, according to Craddock.
The transition from the Bronze Age to the Iron Age occurred in much of Asia, the Middle East, and Europe around 3,000 years ago. Over 2,000 years prior to this, people were using bronze, an alloy consisting of 90% copper and 10% tin, to produce weapons, armor, and ceremonial vessels. However, such items were highly valuable and often difficult for ordinary people to acquire.
According to archaeologist Alessandra Giumlia-Mair, iron replaced bronze in many applications primarily due to the abundance and relatively low cost of iron ore. Therefore, iron swords and daggers were not necessarily sharper or more durable than their bronze counterparts, but they became popular in the ancient world due to lower production costs. Over time, early blacksmiths developed methods to create harder iron, including steel, making weapons and tools accessible to more people. Nevertheless, copper continued to be used for high-quality products like vessels, lamps, and personal decorations until the Middle Ages.
Today, steel is consistently produced in specialized furnaces using pig iron made from iron ore, refined into various steel alloys at high temperatures while being exposed to oxygen. Different types of steel contain varying amounts of carbon along with other elements such as chromium, which help create stainless steel.
