BRASS

Brass is any alloy of copper and zinc; the proportions of zinc and copper can be varied to create a range of brasses with varying properties. In comparison, bronze is principally an alloy of copper and tin. Despite this distinction, some types of brasses are called bronzes. Brass is a substitutional alloy. It is used for decoration for its bright gold-like appearance; for applications where low friction is required such as locks, gears, bearings, ammunition, and valves; for plumbing and electrical applications; and extensively in musical instruments such as horns and bells for its acoustic properties.

Brass has a muted yellow color, somewhat similar to gold. It is relatively resistant to tarnishing, and is often used as decoration and for coins.

The malleability and acoustic properties of brass have made it the metal of choice for brass musical instruments such as the trombone, tuba, trumpet, euphonium, and the French horn. Even though the saxophone is classified as a woodwind instrument and the harmonica is a free reed aerophone, both are also often made from brass. In organ pipes designed as "reed" pipes, brass strips are used as the "reeds".

Brass has higher malleability than copper or zinc. The relatively low melting point of brass (900 to 940°C, depending on composition) and its flow characteristics make it a relatively easy material to cast. By varying the proportions of copper and zinc, the properties of the brass can be changed, allowing hard and soft brasses.

Today almost 90% of all brass alloys are recycled. Because most brass is nonmagnetic, it can be separated from ferrous scrap by passing the scrap near a powerful magnet. Brass scrap is collected and transported to the foundry where it is melted and recast into billets. Billets are later heated and extruded into the desired form and size.