An iron-base, cobalt-base, or nickel-base alloy that combines high-temperature mechanical properties, oxidation resistance and creep resistance to an unusual degree. Constitutions of these alloys are as follows. Iron-base: 10–45% nickel, 13–19% chromium, 1.3–6% molybdenum, balance iron. Cobalt-base: 0–26% nickel, 0–26% chromium, 0–15% tungsten, balance cobalt. Nickel-base: 55–75% nickel, 10–20% chromium, 0–6% aluminum, 0–5% titanium. All contain less than 0.5% carbon, plus other special ingredients. Superalloys can be used up to 2500F.