How was bronze made from copper and tin?

Bronze was created by smelting copper and tin ores together, a process that marked a significant advancement in metallurgy. While early metalworkers initially used copper alone, they eventually discovered that smelting copper-bearing ore with tin-bearing ore produced a superior alloy that was harder, more durable, and easier to cast than pure copper.12

The production process involved several key steps:

• Smelting: Raw ores were heated in furnaces with charcoal to create a reducing atmosphere, which separated the metal from the ore.2
• Alloying: By combining copper and tin, the resulting bronze achieved a lower melting point than copper, which increased the liquidity of the melt and facilitated the use of complex molds.2
• Casting: Because bronze expanded slightly before solidifying, it captured the fine details of molds better than copper, allowing for the creation of sophisticated tools and weapons.2

Over time, metalworkers refined these techniques to control the tin content—typically around 10 percent—to optimize the hardness and strength of the final product for various hand tools, such as axes, adzes, and chisels.32