Vacuum Form. Vacuum forming can create many thin, weak molds in a short period of time. Permanent Mold. Permanent molds are often made of steel, iron, silicone or urethane, and Die Casting. Die casting is the preferred method for creating many small castings.

Casting steel at home could pose a major challenge. Getting a crucible furnace to the temperature needed to pour steel is possible, but it will turn your furnace into a consumable. Once you have any quantity of molten metal, moisture becomes an extreme danger. A drop of molten metal on concrete (which holds moisture) will turn the water in the pore

Permanent mold casting is a metal casting process that employs reusable molds ("permanent molds"), usually made from metal. The most common process uses gravity to fill the mold, however, gas pressure or a vacuum is also used. Other materials include tin, zinc, lead alloys, and iron and steel are also cast in graphite molds.