Alloy of copper and zinc, important for its hardness and workability. Brass was first used c. 1200 BC in the Near East, then extensively in China after 220 BC, and soon thereafter by the Romans. In ancient documents, including the Bible, the term brass is often used to denote bronze (copper/tin alloy). The malleability of brass depends on its zinc content; brasses with more than 45% zinc are not workable. Alpha brasses contain less than 40% zinc; beta brasses (40–45% zinc) are less ductile than alpha brasses but stronger. A third group includes brasses with additional elements. Among these are lead brasses, which are more easily machined; naval and admiralty brasses, in which a small amount of tin improves resistance to corrosion by seawater; and aluminum brasses, which provide strength and corrosion resistance where the naval brasses may fail.