A new cast alloy G 45 Mo has been developed as an alternative to the conventional wrought A825 A625 and Ni-Cr-Mo alloys normally used in the chemical industry or for the most severe conditions in the On-/Offshore industry. The chemical composition of the cast version of a wrought alloy is often only slightly altered compared to its wrought counterpart. In this case however the newly developed alloy fully uses the advantages that the casting process offers over forgings. The alloy is based on the high carbon 35Cr/45Ni family of cast alloys which have been successfully used for the past 20 years for high temperature service within the petrochemical industry. The carbon content has been limited and alloying elements such as Mo Cu and N have been added intentionally. The result is an alloy that is ductile thermally stable and in the solid solution annealed form exhibits a minimum proof strength of 350 MPa with a typical values slightly below 400 MPa. The corrosion resistance is equal or even in some media superior to the commercial wrought A59. Due to the lower amounts of Ni and Mo the alloy is a more cost efficient alternative to the conventional Ni-Cr-Mo alloys with similar or even better mechanical strength and corrosion resistance.