Re: Why did people switch from using bronze to using iron?

Schyler,

The Iron Age was said to have started in the 12th Century B.C.E. near India. Many civilizations made the switch much more gradually though, leading to Europe's Iron Age in the 8th Century B.C.E. and West Africa's by 1200 B.C.E. The Iron Age was said to have ended as early as the 6th century B.C.E. in India, and may have extended up to 500 C.E. in Europe.

The first and most obvious reason was supply. In this diagram, the more common elements in Earth's crust are in the green area, while less common ones are not. Iron, or [Fe], is much more common than bronze (which is usually an alloy of Copper[Cu] and Tin[Sn]). Weapons and tools were made of whatever metal was at hand and iron was much easier to find.

The next incentive to switch was an advance in technology. Bronze's melting point is about 430 degrees Celsius, and iron melts at about 1535 degrees Celsius. For a comparison, a campfire burns at about 400 degrees Celsius - bronze was obviously much easier to melt down and shape. However, as technology improved, civilizations were able to heat their materials to a greater degree and were able to use more metals for their tools. That's why iron was used much more as time went on.

In the end, it all came down to these two reasons. Tin became difficult to find as time went on; this forced civilizations to look for different metals to forge. Since iron was so widely available, it was a logical step up from bronze.