Permanent Casting utilizes a metal mold of two or more parts, which is used repeatedly for the production of many castings of the same form. Molten metal is poured into the mold, utilizing gravity or low-pressure to fill the die.

Gravity Die casting employs cast iron moulds which allow castings to be produced more accurately and cheaply than with sand casting. Tooling costs are a fraction of those needed for pressure die casting. The rapid chilling gives excellent mechanical properties whilst non-turbulent filling ensures production of heat treatable castings with minimal porosity