The author describes two interesting nickel-base alloys developed with properties useful for gas-turbine applications at temperatures up to at least 1500 F. The first of these alloys, Inconel X, is a wrought material, readily forged and welded, with high rupture strength at all temperatures up to 1500 F and possibly higher. In addition to its use in gas turbines, Inconel X appears to offer promise as a spring material operating at temperatures of 900 F or more. The material has also been supplied experimentally in sheet form for aircraft manifold assemblies, tail pipes, and similar components. It has been produced commercially in ingot sizes as large as 5000 lb and is available in billets, simple rod sections, wire, sheet, and strip and may soon be available in tubing form. The second of the two alloys is a cast material primarily suited for extended service applications requiring high creep resistance in the neighborhood of 1500 F. The alloy has good casting qualities and is resistant to thermal shock, thereby making possible the use of high temperature heat-treatment.