Base metal Copper is also considered a base metal because it oxidizes relatively easily, although it does not react with HCl. In mining and economics, the term base metals refers to industrial non-ferrous metals excluding precious metals. These include copper, lead, nickel and zinc. The U.S. Customs and Border Protection is more inclusive in its definition. It includes, in addition to the four above, iron and steel, aluminium, tin, tungsten, molybdenum, tantalum, cobalt, bismuth, cadmium, titanium, zirconium, antimony, manganese, beryllium, chromium, germanium, vanadium, gallium, hafnium, indium, niobium, rhenium and thallium, and their alloys. Zamak is an alloy used in casting (metalworking) which
Brass bell of metal. The use of metal also avoids the risks of exposing wooden instruments to changes in temperature or humidity, which can cause sudden cracking. Even though the saxophones and sarrusaphones are classified as woodwind instruments, they are normally made of brass for similar reasons, and because their wide, conical bores and thin-walled bodies are more easily and efficiently made by forming sheet metal than by machining wood. The keywork of most modern woodwinds, including wooden-bodied instruments, is also usually made of an alloy such as Nickel Silver/German Silver. Such alloys are stiffer and more durable than the brass