A process of producing precision castings of steel or steel alloys, which comprises first forming the steel or steel alloy in molten form by the aluminothermic process, by igniting a mixture of iron ore and aluminum; then running the molten metal into a mold prepared by packing a refractory mold composition around a model made of wax or other comparatively low-melting-point substance and heating to melt out the wax and consolidate the mold; and finally centrifuging the mold.