Monel 400 or Alloy 400 (UNS N04400) is a nickel-copper alloy with superior corrosion resistance, moderate/high strength and good weldability. Monel 400 is resistant to a variety of corrosive conditions such as acidic applications involving hydrofluoric acid, saltwater, sulfuric acid and alkalies. Alloy 400 can only be hardened by cold working. Monel 400 is used across many industries especially marine and chemical processing due to it's superior corrosion resistance.

400's mechanical properties in sub zero temperatures are excellent. The strength and hardness of Alloy 400 increase with only a minor decrease of impact resistance or ductility and  can maintain its toughness over a large range of temperatures.

Monel Alloy 400 when compared to other higher copper alloys is for the most part more resistant to attack by oxidizing. Those attributes of Alloy 400 make it suitable in a variety of environments, especially in marine environments

Monel 400 is available round bar, tubing, flat bar, hex bar, pipe, plate, sheet, coil and square bar.