Chapter 6 Copper Production Technology
discovered that heat made copper more malle-able. Casting and smelting of copper began around 4000-3500 B.C. (see figure 6-2). About 2500 B. C., copper was combined with tin to make bronze—an alloy that allowed stronger weapons and tools. Brass, an alloy of copper and zinc, probably was not developed until 300 A.D.