Bronze is manufactured out of copper and has a natural, pinkish color. It is used in hardware because it is both stronger and harder than its parent metals. While copper may corrode more quickly, bronze can withstand the elements better. True bronze is made of 10 percent tin and 90 percent copper and used commercially. Bronze used in architecture contains 57 percent copper, with 3 percent lead and 40 percent zinc. Statuary bronze contains 97 percent copper, 2 percent tin and 1 percent zinc.
There are many pros and cons to using bronze in different types of construction. For example, bronze is resistant to weak acids and different types of environments and atmospheres. This resistance is one of the reasons it is used in outdoor statuary; however, bronze is negatively affected by certain ammonia compounds, pollution, acid rain and bird droppings. Some chemicals, such as nitrogen oxide, chlorine and sulfur, are especially harmful to bronze. Once bronze is manufactured from copper, it starts to deteriorate because it is not a natural metal. Most outdoor bronze has a finish or patina on it, which helps to protect it from the elements and slow the deterioration process.Learn more about Manufacturing