Monel® alloy 400

UNS N04400
W.Nr 2.4360/2.4361


Valves, pumps, seals, springs, and heat exchangers.


Monel® 400 is a Nickel-Copper alloy with high strength and toughness and remains ductile even at subzero temperatures. Age-hardening treatments are not required to obtain the high strength properties of Monel® 400 because it is a solid-solution alloy that is hardened only through cold working. Monel® 400 is resistant to corrosion in many reducing environments, offering excellent corrosion resistance in seawater, hydrofluoric acid, sulfuric acid, and hydrochloric acid. Monel® 400 also shows resistance to stress corrosion cracking and pitting in fresh water, is resistant to oxidization and can operate from cryogenic temperatures to 500°F (260°C).

Industries Supplied

Oil & Gas Extraction, Marine, Chemical and Petrochemical Processing,

Nominal Composition

Ni: 63.0 - 70.0
Cu: 28.0 - 34.0
Fe: 2.5 max
Mn: 2 max
Si: 0.5 max
C: 0.3 max
S: 0.024 max

Physical Properties

Density: 0.318 lb/in3, (8.8 g/cm3)

Modulus of Elasticity (E): 
At 70°F (20°C): 26.0 x 103 ksi (179 GPa)

Modulus of Rigidity (G): 
At 70°F (20°C): 9.5 x 103 ksi (65.5 Gpa)

Coefficient of Expansion:
8.8 µin/in.-°F (70°F to 600°F)
15.7 µm/m-°C (20°C to 300°C)

Electrical Resistivity: 20.1 µΩ.in, (51.1 µΩ.cm)

Thermal Conductivity: 151 Btu-in/ft2hr-°F, (21.8 W/m-K)

Applicable Specifications

Wire & Bar: AMS 4730, AMS 4675, ASTM B164, BS 3075 NA 13, DOD QQ-N-281, NACE MR0175 (ISO 1516-3).

Typical Mechanical Properties – Spring Applications

  • Annealed
    • Heat Treatment: 1650°F (900°C)
    • Tensile Strength: 70 - 95 ksi; (480-655 MPa)
    • Suggested Operating Conditions: -300°F to 500°F (-184°C to 260°C)

  • Spring Temper
    • Tensile Strength: 145 – 180 ksi; (1000 – 1240 MPa)
    • Suggested Operating Conditions: -300°F to 500°F (-184°C to 260°C‚Äč)

    Monel® is a registered trademark of the Special Metals Corporation group of companies.

    For further information Contact:

    Phone: 1 847 695 1900 
    Elgiloy Specialty Metals - Wire Products
    356 N.Cross Street
    Sycamore, IL 60178 USA