Various types of metals can be used in sculptural art, with bronze being the most popular alloy metal for casting. Durable and hard, yet malleable and fairly easy to bend or hammer into desired shapes, metal can also be melted and molded during the casting process. Metals fall into two types: ferrous and non-ferrous. Ferrous metals include cast iron or wrought iron—any metals that contain iron. Non-ferrous metals include aluminum, alloys, bronze, stainless steel, copper. Non-ferrous metals have been used in numerous practical and artistic applications since the beginning of civilization.