Alloy 400

Alloy 400 Nickel Pipe

UNS N04400 / W.Nr. 2.4360

COMMON TRADE NAMES: Monel® 400, Nickel-Copper

Alloy 400 is a nickel-copper alloy exhibiting excellent corrosion resistance in seawater, marine atmospheres, organic acids, and other aggressive media. Alloy 400 exhibits outstanding corrosion resistance, high strength, and toughness over a wide range of temperatures. It is a solid solution strengthened alloy with a nominal chemical composition of 66% nickel, 31% copper, and additions of iron and manganese. It is referred to by the tradename Monel® 400 and the universal designation UNS N04400.


Corrosion graphic

Corrosion Resistance

Alloy 400 exhibits outstanding corrosion resistance in seawater, reducing acids, non-oxidizing salts, alkalis, high-temperature steam, and other media. It is one of the few alloys that can withstand unaerated hydrofluoric acid and is virtually immune to chloride stress corrosion cracking. However, it is not suitable for oxidizing acids and salts.
Mechanical Properties

Mechanical Properties

Alloy 400 can be provided in the lower strength, annealed condition, or strengthened through the pilger process. Alloy 400 maintains excellent toughness even in the higher strength conditions and does not become brittle at temperatures down to ¬320°F (-196°C).
heat treatment logo

Heat Treatment

While Alloy 400 cannot be strengthened by heat treating, annealing or stress relieving are commonly used after hot working or cold working operations to restore ductility and corrosion resistance.


Applications for Alloy 400 are found in many different market segments, including oil & gas, chemical processing, marine, piping, heat exchangers, transportation, agriculture, and aerospace. CRA offers specialty alloy 400 seamless pipe & tube for use in multiple industries in a wide range of critical applications, including:

  • Oil & Gas
  • Chemical Processing
  • Marine
  • Transportation
  • Agriculture
  • Aerospace
  • Piping

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Chemical Composition

CFeMnSiCuSAlNi + Co
≤ 0.3≤ 2.5≤ 2≤ 0.528 - 34≤ 0.024≤ 0.563 - 70
(mass %)


ASTM B163, ASTM B165, ASME SB163, ASME SB165, AMS 4574, MIL-T 1368

Specified Mechanical Properties in Annealed Condition

Per ASTM B163 / ASTM B165, ASME SB163 / ASME SB165, AMS 4574, MIL-T 1368

Tensile StrengthYield StrengthElongation
minimum, ksiminimum, ksiminimum, %
*Higher strength properties can be provided in the cold hardened condition.

Typical Physical & Mechanical Properties in Annealed Condition

Thermal ExpansionX10-6/°F-
Elastic Modulus103 ksi26----
Poisson Ratio-0.32----
Thermal ConductivityBtu-in/h·ft2 ·°F151167193215238
Specific HeatBtu/lb·°F0.1020.1050.110.114-
Yield Strengthksi2822201919
Tensile Strengthksi7061575554

Manufacturing Process

Steel MakingElectric Arc Furnace followed by Vacuum Oxygen Decarburization (VOD) or Argon Oxygen Decarburization (AOD).
Pipe MakingConventional Seamless Cold Finished Pipe and Tube Manufacturing Processes.
Heat TreatmentCannot be hardened by heat treatment. May be provided in the annealed or cold hardened condition.

Manufacturing Capabilities

CRA offers this alloy in:
Seamless Pipe

MIN OD: 2-1/16″ (2.0625″)
MAX OD: 10-3/4″ (10.750”)
THICKNESS: Up to 1.925”
LENGTHS: Up to 70′

Standard & Non-Standard Sizes Available.

Manufactured Material Available as Quickly as 1 Week.

Non-Standard Mill Quantities Accommodated