1.1 This specification covers iron-chromium and iron-chromium-nickel alloy castings for heat-resistant service. The grades covered by this specification are general purpose alloys and no attempt has been made to include heat-resisting alloys used for special production application.Note 1—For heat-resisting alloys used for special product application, reference should be made to Specification A 351/A 351M, A 217/A 217M, and A 447/A 447M.1.2 The values stated in either inch-