Nickel Alloy 400 and Monel 400, also known as UNS N04400, is a ductile, nickel-copper based alloy comprised essentially of two-thirds nickel and one third copper. Nickel Alloy 400 is known for resistance to a variety of corrosive conditions, including alkalies (or acid like substances), saltwater, hydrofluoric acid and sulfuric acid. Other advantages of using this alloy are its toughness and high strength over a broad temperature range; it can also be manipulated to become magnetic if desired. Fortunately, if Nickel Alloy 400 doesn’t meet your specific needs, NSA stocks other nickel-copper based alloys to choose from.