Diagram depicting a type of inversion casting:
1) core pins are inserted into a hollow wax model;
2) the sprue system is fused onto the wax model;
3) the wax model is covered in a refractory investment material;
4) the mold is then heated until dry and all traces of the wax melted and burned out;
5) meanwhile, a simple receptacle that will serve as a crucible is shaped of refractory material; small pieces of bronze and charcoal are placed in the crucible, which is luted to the mold to form an enclosed unit;
6) the mold-crucible is heated until the metal is molten;
7) the mold with its integral crucible is then inverted to allow the liquefied bronze to pour quickly into the mold; the charcoal helps to reduce oxidation;
8) fettling includes breaking off the refractory mold, removing the core pins, and cutting away the sprue system;
9) chasing may consist of polishing, burnishing, and the addition of details as needed; the surface color may also be enhanced with inlays, coating, plating, and/or patination.