How is bronze made from copper and tin?

Bronze is an alloy traditionally created by adding tin to copper. By combining these metals, the resulting material becomes harder, stronger, and more resistant to corrosion than pure copper. Additionally, bronze has a lower melting point than copper, which makes it significantly easier to cast.12

While modern bronze typically consists of approximately 88 percent copper and 12 percent tin, historical proportions have varied widely depending on the desired application. For example, softer gunmetal has been produced using a ratio of 16 parts copper to one part tin, while harder varieties used for cannons historically contained about eight parts copper to one part tin.12

Beyond the basic copper-tin mixture, other elements may be added to enhance specific properties. For instance, small amounts of phosphorus can be added to increase hardness and strength, creating phosphor bronze. Other metals, such as aluminum, manganese, or zinc, may also be substituted or added to tailor the alloy for specialized industrial uses.12