depend on the metal you are using.
aluminum you will need (at a minimum)
* Appropriate safety gear.
* A furnace capable of melting the charge.
* A crucible to hold the charge, unless your furnace is a type that
holds the metal directly.
* Work area for safely doing your casting, and somewhere to store your
* Handling equipment for the crucible, like tongs and shanks.
* Something to pour the molten metal into. An ingot mold or a pattern
mold, preferably both.
* A charge of metal to melt. (scrap or ingots)