Alloy 718 Flange Grade 718 Inconel Flange is the most common grade of the hardenable Inconel. This precipitation-hardened nickel-chromium alloy combines outstanding corrosion resistance and high strength at elevated temperatures. The alloy is an about 2x as strong as Inconel grade 625 having excellent creep-rupture strength at temperatures to 1300¡ãF (700¡ãC) and usable up to 1800¡ãF (982¡ãC). Inconel grade 718 is often used in gas turbines, rocket motors, spacecraft, nuclear reactors, pumps, and tooling.