What is Bronze? (from www.wisegeek.com)

Bronze is a metal alloy produced by blending copper and tin. Additional elements such as manganese, lead, and phosphorous are added to create bronze with specific properties. Bronze is found in bells, statuary, bearings, gears, valves, pipes, and other plumbing fittings, and it is a sturdy, durable metal when well cared for. Humans have been working with bronze for over 3,000 years in various parts of the world, using it for weapons, coins, tableware, and an assortment of other household purposes.

Bronze is made by smelting copper and tin together. When bronze is cast for use in statues, it contains between 2% and 20% tin, while bells use a higher percentage of tin: 15-20%. Additives are included when the bronze needs to be more workable, harder, or easier to cast. For example, phosphorous is added to harden bronze for use in tubing and various machine parts, while lead is included to make bronze take more readily to casting. Bronze is often confused with brass, an alloy of copper and zinc, but the two alloys have different properties and are used for different things. In addition, bronze is much harder than brass.