UNS N08810/UNS N08811-Incoloy 800 H is a nickel-iron-chromium alloy that shares the same basic composition as Incoloy 800 but has a significantly higher creep rupture strength. The increased strength is due to strict control of the carbon, aluminium, and titanium content, as well as a high temperature anneal. The 800H modification was made to regulate the carbon content (0.05 to 0.10 percent) and grain size (>ASTM 5) in order to optimise the stress rupture properties. To ensure the best high temperature properties, Incoloy 800 H has additional titanium and aluminium modifications (0.85 to 1.2 percent). Dual certified, the alloy combines the properties of the two forms. The chemical balance of the alloy enables it to resist carburization, oxidation, and nitriding atmospheres exceptionally well. Even after prolonged exposure to temperatures between 1200 and 1600 degrees Fahrenheit, where many stainless steels become brittle, 800HT will not become embrittled.