This SAE Standard covers the hardness, chemical analysis and microstructural requirements for ductile iron castings intended for high temperature service in automotive and allied industries. Commonly known as SiMo ductile iron, typical applications are in piston-engine exhaust manifolds and turbocharger parts. Castings may be specified in the as-cast or heat treated condition. For design purposes, the Appendix provides general information on the application of high temperature ductile iron castings, their processing conditions, chemical composition, mechanical properties and microstructure.