Editing Metal casting (section)

{{Short description|Pouring liquid metal into a mold}}
[[File:Molten metal.jpg|thumb|Molten metal before casting]]
[[Image:casting.jpg|thumb|Casting iron in a sand mold]]

In [[metalworking]] and jewelry making, '''casting''' is a process in which a liquid metal is delivered into a [[Mold (manufacturing)|mold]] (usually by a [[crucible]]) that contains a negative impression (i.e., a three-dimensional negative image) of the intended shape. The metal is poured into the mold through a hollow channel called a [[Sprue (manufacturing)|sprue]]. The metal and mold are then cooled, and the metal part (the ''casting'') is extracted. Casting is most often used for making complex shapes that would be difficult or uneconomical to make by other methods.<ref>{{Harvnb|Degarmo|Black|Kohser|2003|p=277}}</ref>

Casting processes have been known for thousands of years, and have been widely used for [[sculpture]] (especially in [[bronze]]),  [[jewelry]] in [[precious metal]]s, and weapons and tools.  Highly engineered castings are found in 90 percent of durable goods, including cars, trucks, aerospace, trains, mining and construction equipment, oil wells, appliances, pipes, hydrants, wind turbines, [[nuclear plants]], medical devices, defense products, toys, and more.<ref>{{Cite web|url=https://www.afsinc.org/about-metalcasting|title=About Metalcasting &#124; American Foundry Society|access-date=2021-01-12|archive-date=2023-06-07|archive-url=https://web.archive.org/web/20230607083646/https://www.afsinc.org/about-metalcasting|url-status=live}}</ref>

Traditional techniques include [[lost-wax casting]] (which may be further divided into [[centrifugal casting (disambiguation)|centrifugal casting]], and [[vacuum assist direct pour]] casting), [[plaster mold casting]] and [[sand casting]].

The modern casting process is subdivided into two main categories: expendable and non-expendable casting. It is further broken down by the mold material, such as sand or metal, and pouring method, such as gravity, vacuum, or low pressure.<ref>{{Harvnb|Degarmo|Black|Kohser|2003|p=278}}</ref>