Alloy 400 is a ductile nickel-copper alloy with resistance to a wide range of corrosive environments. This grade is often chosen to handle sulfuric acid through 80% concentration at room temperature, and about 15% H2SO2 boiling. Alloy 400 possesses useful resistance to aerated hydrochloric acid up to 10% concentration at room temperature. The alloy has excellent resistance to sea or brackish water under high-velocity conditions. Alloy 400 is one of the few materials with good resistance to hydrofluoric acid.


400 Pipe, 400 Plate, 400 Sheet, 400 Weld Wire

Common Trade Names

Monel 400, Alloy 400


  • Resistant to a variety of corrosive environments
  • Freedom from chloride stress corrosion cracking
  • Good strength and toughness over a wide temperature range
  • Useful resistance to dry chlorine, fluorine hydrogen chloride and hydrogen fluoride gases


  • Crude oil distillation towers
  • Marine components
  • Valve and pump components
  • Chemical processing equipment
  • Caustic evaporators
  • Oil and gas applications
  • Hydroflouric acid production
  • Salt production equipment