Cast iron is brittle, hard and more fusible than steel. It is also nonmalleable, which means that it cannot be stretched, hammered or bent into shape. Its has a crystalline structure, and it is weak in tension.
Copper is generally considered as an inflexible metal. It is melted to a liquid, poured into molds and then sawed, filed and machined. Under excessive tensile loading, cast iron becomes fractured even with little prior distortion. However, it is good in compression. Its stiffness and dampening properties make it a great material for machine parts and tool frames.
Cast iron is one of the oldest ferrous metals commonly used in outdoor ornaments and construction. It consists of iron, carbon and silicon with traces of sulfur, phosphorus and manganese. It contains 2 percent to 5 percent carbon content. Grey cast iron is the most common traditional form. It is easily cast, although it cannot be worked or forged mechanically. On the other hand, white cast iron, which is also called "spheroidal graphite" iron, has superior malleability and tensile strength.
After being manufactured, cast iron produces a protective film on its surfaces that initially makes it more resistant to corrosion than mild steel or wrought iron. Typically, finishing includes paints, waxes, galvanizing, bituminous coatings and plating. Various treatments are also applied to reduce corrosion and rusting.