Copper Alloys, Copper-Nickel (Cupro-Nickel)DEFSTAN 02-780 (NES780) Bar & Tube

A 70/30 copper-nickel alloy with small additions of iron and manganese to improve resistance to high velocity seawater.

Copper nickel 70/30 is stronger than the more common copper nickel 90/10 and is able to withstand corrosion at higher velocities in marine applications, making it the favourable choice in submarine systems. Righton Blackburns carries the UK's largest range of product in this alloy.

70/30 is a 70% copper, 30% nickel alloy with additions of iron and manganese. These elemental additions make it somewhat more resistant to corrosion and erosion and with slightly improved strength level than 90/10, making it suitable for more demanding applications. In particular, its corrosion resistance is notably improved in high-velocity waters (up to 4.5m/s) and polluted seawater.

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Product FormSize RangeWall Thicknesses

Round Bar DEFSTAN 02-780

25mm - 230mm-
Tube DEFSTAN 02-7806mm - 159mmVarious
If you do not see what you are looking for, please contact your local service centre with your specific requirements.

Related Specifications

NES 780 copper nickel corresponds to the following designations but may not be a direct equivalent:

  • CN107
  • C71500
  • NES 780
  • CW354H


Chemical Composition


  • Salt water flanges, salt water piping and pipe fittings, valve bodies, sea water intakes, pipe
  • fittings, water boxes, propeller sleeves, pump bodies and parts
  • Marine hardware
  • Heat exchangers
  • Condensers
  • Desalination units
  • Evaporator tubes, distiller tubes, refrigerator and condenser components
  • Flexible metal hose
  • Boiler parts
  • Pipework
  • Submarine components


  • Excellent corrosion and pitting resistance in marine environments
  • Good strength and toughness
  • Resistance to biofouling
  • Readily weldable and fabricated

Additional Information

NSN Codes for Tube to NES 780 Part 3 Issue 3

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