The choice of metal represents a critical component of the sand casting process. Common alloys used in sand casting include cast iron, aluminum, and various steel grades. Each metal has its properties, such as melting point, flow behavior, and strength, which influence the casting process. For instance, gray cast iron is favored for its excellent fluidity and machinability, while aluminum alloys are lauded for their lightweight and corrosion resistance. The selection of metal depends on the application, required mechanical properties, and economic considerations.