Nickel Alloys Monel 400 N04400

Product Data Sheet – Nickel Alloys

 Monel 400  UNS-N04400

Monel K-500 is a versatile nickel copper alloy with good strength and toughness, combined with outstanding corrosion resistance. Monel R-405 is a free cutting version with similar properties.

Chemical Composition

ASTM B127 – Plate, sheet & strip

NickelCopperIronManganeseSiliconCarbonSulphur (Monel 400)Sulphur (Monel R-405)
63.0 min28.0-34.02.5 max2.0 max0.5 max0.3 max0.024 max0.025-0.060

Equivalent Specifications

GermanyDIN2.4360, 2.4361

 ASTM Product Specifications

Seamless Nickel and Nickel Alloy Condenser and Heat-Exchanger Tubes
Factory-Made Wrought Nickel and Nickel Alloy Fittings
Nickel Alloy Forgings
Nickel-Copper Alloy (UNS N04400) Plate, Sheet, and Strip
Nickel-Copper Alloy Rod, Bar, and Wire
Nickel-Copper Alloy (UNS N04400) Seamless Pipe and Tube
Welded Nickel (UNS N02200/UNS N02201) and Nickel Copper Alloy (UNS N04400) Pipe
Welded Nickel (UNS N02200/UNS N02201) and Nickel Copper Alloy (UNS N04400) Tube


Specified Minimum Mechanical Properties

ASTM B127 – Plate, sheet & strip

0.2% Proof Stress
Tensile Strength
As Hot Rolled27551525

Available Forms Austral Wright Metals can supply Monel 400 as plate, sheet and strip, rod and bar, seamless and welded tube and pipe, condenser and heat exchanger tube, welding fittings, forgings and forging billet, wire. Monel R-405 is available as rod and bar.

General Description Monel 400 is a nickel copper alloy with good strength and ductility, good weldability and excellent resistance to corrosion. It is tough over a wide range of temperatures. It is often used in marine applications. Corrosion rates in strongly agitated and aerated sea water are extremely low. The alloy has useful properties to 540°C in oxidising atmospheres and higher temperatures in reducing conditions. Monel 400 is readily welded and brazed.

Typical applications Chemical plant, valves and pumps, pump & propeller shafts, marine fixtures and fasteners, electrical components, springs, gasoline & fresh water tanks, petroleum stills, process vessels & piping, boiler feedwater heaters and other heat exchangers, deaerating heaters.

Physical Properties

Metric Units
Melting Range
8,800 kg/m³ @ 20°C
Coefficient of Thermal Expansion
13.9 x 10 -6 / °C (20°C)
Curie Temperature
Themal Conductivity
21.8 W/m. °C @ 20°C
Thermal Capacity (Specific Heat)
427 J/kg. °C @ 20°C
Electrical Conductivity
32 % IACS
Electrical Resistivity
0.547 microhm.m @ 20°C
Modulus of Elasticity (tension)
179 GPa @ 20°C
Modulus of Rigidity (torsion)
65.5 GPa @ 20°C
Poisson’s Ratio


Nickel Alloys Monel 400 N04400 TemperatureIsocorrection Nickel Alloys Monel 400 N04400

High temperature tensile properties of annealed Monel 400

Isocorrosion chart of Monel 400 in hydrofluoric acid

Corrosion Resistance

Monel 400 is generally more corrosion resistant that both of the major constituents nickel and copper. It is highly resistant to chlorinated solvents, glass etching agents, sulphuric, hydrofluoric and many other acids, and practically all alkalies. The alloy gives excellent service in sea water under high velocity conditions, where resistance to cavitation and erosion are important. Corrosion rates in strongly agitated and aerated sea water are extremely low. It is generally free from chloride stress corrosion cracking, but only annealed material resists stress cracking in the presence of mercury or mercury salts, and in moist, aerated hydrofluoric acid vapour. It should not be used for nitric acid service. Please consult Austral Wright Metals for specific advice on your application.

Pressure Vessels

AS1210 & ASME Boiler & Pressure Vessel Code pre-qualify Monel 400 for use in pressure vessels up to about 475°C.


Monel 400 can be readily hot worked, with lower forces than many steels. The alloy can easily be cold formed, with forces between those of carbon steel and grade 304 stainless steel.



Monel 400 is easy to machine (class B). Sharp tools, slow speeds and deep uninterrupted cuts to remove the work hardened layer are needed. Monel R-405 is a free cutting version of Monel 400, for rapid production in automatic screw machines. Toughness, strength and corrosion resistance are very similar to Monel 400.



Monel 400 is readily welded by GMAW (MIG), GTAW (TIG), SMAW (manual) and SAW processes. Preheat, post heat and post weld heat treatment are not required. The area around the weld must be clean to prevent contamination of the weld pool. Argon shielding gas is used.

Heat Treatment

Monel 400 is annealed at 870–980°C, cooling rate not critical. Grain growth is rapid in this alloy, so use the lower end of the temperature range and minimal time to retain good strength. Stress relief, if required, is at 540-570°C. Stress equalising cold worked material at 300°C markedly increases the proof stress, without affecting other properties.

Filler Metal Selection

Self Welds

Normal ServiceHigher StrengthBest Corrosion Resistance
Welding ElectrodeMonel WE 190Monel WE 190Monel WE 190
Filler MetalMonel FM 60Monel FM 60Monel FM 60
Flux Cored WireInco-Cored 82DH
The technical advice and recommendations made in this Product Data Sheet should not be relied or acted upon without conducting your own further investigations, including corrosion exposure tests where needed. Please consult current editions of standards for design properties. Austral Wright Metals assumes no liability in connection with the information in this Product Data Sheet. Austral Wright Metals supplies a comprehensive range of stainless steels, copper alloys, nickel alloys and other high performance metals for challenging service conditions. Our engineers and metallurgists will be pleased to provide further data and applications advice.