“For much of history, investment casting was confined to sculpture and works of art."
European Investment Casters' Federation
Investment casting is one of the oldest metalworking practices, occurring as long ago as 3000 B.C.E., and remains vital in producing very specific, one-piece metal designs. Today, the process is used to produce complex parts for nuclear power plants, but thousands of years ago essentially the same method was used to produce small metal ornaments and statues.
Civilizations such as the Egyptians and the Mesopotamians used the investment casting—or "lost wax"—process to create small idols or jewelry with intricate patterns. The intended shape and design of each object was first sculpted from natural beeswax, and then coated with several layers of thick and heat-resistant plaster. This mold was then heated, the wax inside melted and drained out, and molten metal was poured into the resulting hollow space. After cooling, the plaster was removed, to reveal metal in the exact shape of the wax template.
During World War II the process was adopted extensively to produce precise components for military machinery, a trend that continued after the end of the war and expanded into other commercial industries. With the expansion came more refined ways of implementation, such as more advanced waxes, but the basic ingredients of the process have remained unchanged in millennia.
