pot metal

Pot metal—also known as monkey metal, white metal, or die-cast zinc—is a colloquial term that refers to alloys of low-melting point metals that manufacturers use to make fast, inexpensive castings. The term "pot metal" came about due to the practice at automobile factories in the early 20th century of gathering up non-ferrous metal scraps from the manufacturing processes and melting them in one pot to form into cast products. A small amount of iron usually made it into the castings, but too much iron raised the melting point, so it was minimized.