Castings are finished shapes associated with the molding of liquid substances into solid forms. This process is widely used in art as well as manufacturing. Its advantages lie in the ability to mass-produce pieces that will be identical in design, size, and weight simply by using the same mold. Castings most commonly used in the automotive industry, for example, are whole engine blocks and cylinder heads. Generally speaking, the metals are liquefied and then poured into the molds. After hardening, the molds are removed, and the finished castings await further treatments.
Other kinds of castings are those made during the process of die-casting. Again liquefied metal is used, but instead of pouring it into a mold, it is forced into a die, where the applied pressure keeps it in place until it hardens. This process is known for the high speed applications it supports, such as the manufacture of carburetor bodies and zippers.
Other types of castings involve the mixture of gravel with sand, cement and water, also known as concrete. While the methods mentioned above relied on hot, molten metals to be shaped, this method actually refers to the molding of a cold, wet substance. The creation of ornamental statuaries, rocks and benches for home and garden use, as well as the manufacture of driveway slabs, curbs, and center dividers for public use rely on this process. In addition to the this methodology, other types of castings may be those that rely on the molding process to get started, but after an initial hardening will require further treatment. Such is the case with clay. If used in a mold, it will take on the shape of its mold, but it will not retain rigidity until it is fired in a kiln after the initial drying process.
