Metals and alloys are materials that are typically hard, malleable, and have good electrical and thermal conductivity. Alloys are made by melting two or more elements together, at least one of them a metal. They have properties that improve those of the constituent elements, such greater strength or resistance to corrosion.

Commercial and trade alloys generally require greater processing and are most often formed by mixing molten metals in a controlled environment. The procedure for combining molten metals or mixing metals with nonmetals varies greatly depending on the properties of the elements being used.