casting

casting or founding, shaping of metal by melting and pouring into a mold. Most castings, especially large ones, are made in sand molds. Sand, mixed with a binder to hold it together, is pressed around a wooden pattern that leaves a cavity in the sand. Molten metal is poured into the cavity and allowed to solidify. Permanent metal molds are used to make many small, simple parts; shell molding gives greater accuracy for a large volume of semiprecision parts. A two-step process, investment casting, produces small, complex shapes. Wax or plastic replicas of the parts are molded in accurate metal molds. These replicas are covered with sand in a box to make the final mold. When the whole mold is heated, the replica melts, leaving behind a cavity into which metal is poured. Large numbers of small, precise parts of metals that have a low melting point, such as zinc, are made by die-casting; in an automatic process, molten metal is forced under pressure into metal molds. Cast iron and cast steel are more brittle than forged iron and forged steel (see forging).

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casting

Pouring of molten metal into a mold, where it solidifies into the shape of the mold. The process was well established in the Bronze Age, when it was used to form bronze pieces now found in museums. It is particularly valuable for the economical production of complex shapes, ranging from mass-produced parts for automobiles to one-of-a–kind production of statues, jewelry, or massive machinery. Most steel and iron castings (see cast iron) are poured into silica sand. For metals of lower melting point, such as aluminum or zinc, molds can be made of another metal or of sand. See also die casting, founding, investment casting, lost-wax casting, patternmaking.

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casting

In programming, the conversion of one data type into another. See also Webcast, narrowcast, multicast and broadcast.

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casting

1. an object or figure that has been cast, esp in metal from a mould

2. the process of transferring molten steel to a mould

3. the choosing of actors for a production

4. Hunting the act of directing a pack of hounds over ground where their quarry may recently have passed so that they can quest for, discover, or recapture its scent

5. Zoology another word for cast, pellet