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

Brass is a buttery yellow alloy of zinc and copper which has been manufactured for thousands of years all over the world. The uses of brass vary depending on the percentages of zinc and copper, and which other metals have been added to alloy to bring out specific properties, but they include cartridge cases for weapons, pipes, weatherstripping, decorative accents on homes, musical instruments, and household ornaments.

Basic brass has approximately 67% copper and 33% zinc, making it stronger and more durable than copper, although not as strong as metals like steel. Alloys with even less zinc start to turn reddish in color, and are sometimes called red brass. Other metals are sometimes added to the alloy include lead to make brass more workable by machine, tin, arsenic, and antimony to resist corrosion, and iron to make the brass harder and easier to forge.