Ni-Cu 405 (Monel®) (UNS N04405)


Alloy 405 (Monel®) is a ductile nickel-copper alloy with resistance to a variety of corrosive conditions. The alloy is most frequently applied in a range of environments ranging from mildly oxidizing through neutral and to moderately reducing conditions. An additional application area of the material is in marine environments and other non-oxidizing chloride solutions.

Alloy 405 is the free-machining grade of alloy 400. Its greater sulfur content enhances machinability. It has essentially the same corrosion resistance and physical properties as alloy 400, but a slightly different range of mechanical properties. Alloy 405 is used chiefly for automatic- screw-machine stock and is not generally recommended for other applications.  Due to the sulfur addition for free machining, welding is not possible for Alloy 405.

Chemical Composition

Chemical Composition (wt%) limits as specified in ASTM B164*

Carbon 0.3 Manganese 2.0
Nickel 63.0 min Silicon 0.5
Copper 28.0-34.0 Sulfur 0.025-0.060
Iron 2.5    

*Maximum, unless range is indicated

Physical Properties

Physical properties for Alloy 405

Density, lb/in3 0.319
Modulus of Elasticity, psi 26 x 106
Coefficient of Thermal Expansion, 68-212˚F, /˚F 7.7 x 10-6
Thermal Conductivity, Btu/ft hr ˚F 14
Specific Heat, Btu/lb ˚F 0.10
Electrical Resistivity, Microhm-in 20.0

Mechanical Properties

Mechanical property requirements as specified for annealed product in ASTM B164

Yield Strength, min. (ksi) 25
Tensile Strength, min. (ksi) 70
Elongation, min. (%) 35


Typical standards for Alloy 405