Alloy 400 • UNS N04400 • WNR 2.436

Alloy 400, also known as Monel 400, is a nickel-copper alloy that is highly resistant to a variety of corrosive conditions, making it suitable for a wide range of applications.

It is composed of approximately 63% nickel and 28-34% copper, with small amounts of other elements such as iron, manganese, and silicon. This alloy was one of the first nickel-copper alloys developed and remains popular due to its unique combination of properties.

Alloy 400 is known for its excellent resistance to various corrosive environments, including seawater, acids (sulfuric, hydrochloric, etc.), alkaline solutions, and many other chemicals. This makes it ideal for applications in marine, chemical processing, and oil and gas industries.

Available tube product forms

Typical Applications

Typical manufacturing specifications

  • ASTM B163
  • ASTM B165
  • AMS 4574
  • BS3074

Industries predominantly using this grade


Technical Data

Mechanical Properties


Temper Annealed
Tensile Rm 70 ksi (min)
Tensile Rm 480  MPa (min)
R.p. 0.2% Yield 28 ksi (min)
R.p. 0.2% Yield 195 MPa (min)
Elongation (2” or 4D gl) 40 % (min)

Physical Properties (Room Temperature)


Specific Heat (0-100°C) 427 J.kg-1.°K-1
Thermal Conductivity 21.8 W.m -1.°K-1
Thermal Expansion 13.9 μm/μm/°C
Modulus Elasticity 173 GPa
Electrical Resistivity 5.47 Ohm-cm
Density 8.83 g/cm3

Chemical Composition (% by weight)


Element Min Max
C - 0.3
Si - 0.5
Mn - 2
S - 0.24
Cu Balance
Fe - 2.5
Ni 63 70