Nickel-Copper Alloy

Alloy 400 (nickel-copper) is a solid-solution alloy providing good mechanical strength and toughness over a wide temperature range combined with excellent corrosion resistance. 

The alloy exhibits outstanding properties at sub-zero (including cryogenic) temperatures. Strength and hardness increase with only slight impairment of ductility or toughness. Alloy 400 does not undergo a ductile to brittle transition even when cooled to the temperature of liquid hydrogen. The density of alloy 400 is 8.80 g/cc. 

Corrosion Resistance:

Alloy 400 provides excellent resistance to corrosion in a range of media including seawater, hydrofluoric acid, sulphuric acid and alkalis and is widely employed in marine engineering and chemical processing. 

It is more resistant than nickel to corrosion under reducing conditions and more resistant than copper under oxidising conditions. This nickel-copper alloy is therefore in general more resistant to corrosion than either of its two principal constituents. Resistance to stress corrosion cracking in chloride containing media is extremely good. 


Alloy 400 may readily be fabricated, machined and joined using standard processes. 

In general, cold-drawn or cold drawn and stress relieved material provides the best machinability and produces the smoothest finish. All standard welding techniques may be applied to alloy 400. The alloy may also be joined to dissimilar alloys employing appropriate consumables. In addition joining is possible by brazing or soldering. 

Typical Applications:

  • Pump shafts
  • Chemical and hydrocarbon processing equipment
  • Springs
  • Valve trim
  • Marine fixtures and fasteners
  • Heat exchangers
  • Electrical and electronic components
  • Process vessels and piping

Chemical Composition

 Min %Max %
Manganese 0.20
Silicon 0.50
Carbon 0.30
Sulphur 0.024
Iron 2.50

Mechanical Properties

Typical Tensile Strength 550 MPa
Typical Yield Strength 240 M Pa
Typical Elongation 40%