The advantages of Ductile Iron which have led to its success are numerous, but they can be summarized easily - versatility, and higher performance at lower cost. As illustrated, other members of the ferrous casting family may have individual properties which might make them the material of choice in some applications, but none have the versatility of Ductile Iron, which often provides the designer with the best combination of overall properties. This versatility is especially evident in the area of mechanical properties where Ductile Iron offers the designer the option of choosing high ductility, with grades guaranteeing more than 18% elongation, or high strength, with tensile strengths exceeding 120 ksi (825 MPa). Austempered Ductile Iron (ADI), offers even greater mechanical properties and wear resistance, providing tensile strengths exceeding 230 ksi (1600 MPa).

In addition to the cost advantages offered by all castings, Ductile Iron, when compared to steel and Malleable Iron castings, also offers further cost savings. Like most commercial cast metals, steel and Malleable Iron decrease in volume during solidification, and as a result, require attached reservoirs (feeders or risers) of liquid metal to offset the shrinkage and prevent the formation of internal or external shrinkage defects. The formation of graphite during solidification causes an internal expansion of Ductile Iron as it solidifies and as a result, it may be cast free of significant shrinkage defects either with feeders that are much smaller than those used for Malleable Iron and steel or, in the case of large castings produced in rigid molds, without the use of feeders. The reduction or elimination of feeders can only be obtained in correctly designed castings. This reduced requirement for feed metal increases the productivity of Ductile Iron and reduces its material and energy requirements, resulting in substantial cost savings. The use of the most common grades of Ductile Iron "as-cast" eliminates heat treatment costs, offering a further advantage.