Casting is the processes of pouring or pressure feeding molten metal into a mold .

Castings are commonly made from iron, steel, aluminum, zinc, or bronze. Castings are used everywhere, from engine blocks to garden sprinklers. Parts are made from castings instead of machining from stock, for one or more of the following reasons:

1. Too much material would need to be machined away from a piece of stock, so the part would be too expensive to produce by machining alone.
2. The part is so large that stock of sufficient size is not available.
3. The part contains internal holes (such as the internal water cooling hollows in an engine block) that would be impossible to make by machining.
4. The cast metal material has properties (such as rigidity) that a wrought metal stock does not have
5. The metal is extremely difficult to machine

Examples of casting are shown on this page

Most castings require some post-casting machining to produce the finished part. Machining is most often required because of the properties of castings, which are discussed on the following page.