Energy-saving requirements have led to the basic redesign of parts to achieve light weight and high efficiency, which inevitably reminds designers to focus on materials. Ductile iron is increasingly considered to provide high strength-weight characteristics and can be produced at a relatively low cost. When the tonnage of ductile iron increases and the market penetration is amazing, this material must not be seen to reach its full potential. Based on this point, cast iron plants that do not produce ductile iron are recommended to reconsider this possibility. With the replacement of gray cast iron , malleable cast iron and silver castings .