Hastelloy is the prefix name of a family of alloys. Nickel is typically the base alloy, and other ingredients (such as molybdenum, chromium, cobalt, iron, titanium, aluminum and tungsten) are added to the base in varying percentages.

Hastelloy is corrosion resistant and used in high-temperature, high stress environments, such as the aerospace, chemical processing and power generation industries. It has outstanding stress corrosion cracking resistance and resistance to non-oxidizing acids (such as hydrochloric and sulfuric acid).