Although the work of making steel castings is closely associated with the steps in making cast-iron castings, yet there are several requirements of great importance in the preparation of steel moulds which mark the production of steel castings as an art by itself.

The steel foundry is generally an independent branch of industry just as are many branches for the re-manufacture of metals.

Comparing the steel and the iron foundry, their locations are alike in requirements, equipment and interior arrangement are very similar, moulds must embody the same essentials, the same requirements hold for sand used in moulding, and the tools, accessories, and most of the minor moulding materials are the same.

The differences between the requirements of moulds for making cast-iron and steel castings are differences in degree rather than 17 differences in kind. These differences are due (1) to the effects of higher heat of molten steel when poured into the mould, and (2) to its greater shrinkage in cooling, for it does not expand as does cast iron, which precipitates some of its carbon.

The shrinkage of steel is about twice that of cast iron.