The methods used in iron and brass foundries are closely associated, and these two branches are usually under one shop superintendent and in adjacent buildings. The steel foundry is separate, as its methods are enough different to be classed alone.

In location, it is highly important that a foundry site shall be well drained and without an excess of sub-surface moisture. Large moulds must be bedded in pits 8 or 10 feet deep to secure them for withstanding the great pressure of a large bulk of molten metal. If the soil over which the foundry is built is not a loose sand or loam, it must be dug out to a depth of several feet where large moulds are to be bedded and filled in with friable earth not pasty with an excess of clay.