noun: (countable, uncountable) The steel making up a steel casting, in the sense of one cast to finished (net) or near-net shape: the product of a steel foundry (as opposed to a steel mill); the steel counterpart to cast iron.
noun: (archaic, countable, uncountable) Steel that has been poured from (cast out of) a vessel (e.g., crucible, ladle, or furnace) while molten, as opposed to blister steel, which has been formed by carburizing and hammering iron bars.