This SAE Standard covers the mechanical and physical property requirements for austempered ductile iron (ADI) castings used in automotive and allied industries. Specifically covered are: a. hardness; b. tensile strength; c. yield strength; d. elongation; e. modulus of elasticity; f. impact energy; and g. microstructure. In this document SI units are primary and in-lb units are derived. Appendix A provides general information and related resources on the microstructural, chemical and heat treatment requirements to meet the mechanical properties needed for ADI in particular service conditions and applications.