Metal (or their alloys) with relatively low melting points. Such metals include zinc, cadmium, tin, antimony (here counted as a metal), lead, and bismuth, some of which are quite toxic. In Britain, the fine art trade uses the term "white metal" in auction catalogues to describe foreign silver items which do not carry British Assay Office marks, but which are nonetheless understood to be silver and are priced accordingly. A heavy metal is any relatively dense metal or metalloid. More specific definitions have been proposed, but none have obtained widespread acceptance. Some heavy metals have niche uses, or are notably toxic;
Ampco Metal into the production of aluminium bronze alloys as sand castings, forgings and centrifugal castings. The company was renamed "AMPCO METAL" in 1930, by which time it had built itself a reputation as a reliable producer of high quality alloys. The Second World War strongly increased the demand for copper-based alloys and industrial bronzes, especially in the field of aeronautics. By 1944, manufacturing operations had grown from 100 to 2,500 employees, and every American airplane carried AMPCO METAL parts somewhere in its structure—in its engines, landing gear, propellers or airframe. In the marine environment, AMPCO METAL propellers were manufactured for landing