COPPER-NICKEL ALLOY

Copper-Nickel 90/10 Tube Sheet

The economical default for general seawater cooling — good biofouling and corrosion resistance at a lower nickel content and cost than 70/30, adequate for the majority of standard marine condenser applications.

UNS C70600 ASTM B171 / B402 ~10% nickel

Chemical Composition

ElementMin %Max %
Copper (Cu)Balance
Nickel (Ni)9.011.0
Iron (Fe)1.01.8
Manganese (Mn)1.0

Mechanical Properties

PropertyTypical Value
Tensile Strength275 MPa min (annealed)
Yield Strength (0.5% ext.)105 MPa min (annealed)
Elongation30% min
Max. Practical Service Temp.~300°C

Equivalent Grades

StandardDesignation
ASTM / UNSC70600
EN / DINCuNi10Fe1Mn / CW352H

90/10 vs. 70/30 — Which One

Attribute
90/10
70/30
Nickel Content
~10%
~30%
Cost
Lower
Higher
Best For
General seawater cooling, economical default
High-velocity flow, severe biofouling

See the full Copper-Nickel 70/30 datasheet for the higher-nickel premium grade.

Applications

General seawater and brackish water cooling systems, standard marine condensers, and desalination plant condensers operating within moderate flow velocity ranges where 70/30's extra nickel isn't required.

Advantages & Limitations

Advantages

  • Most economical of the copper-nickel marine alloys
  • Good general seawater corrosion and biofouling resistance
  • Long, well-documented service history

Limitations

  • Lower erosion-corrosion resistance than 70/30 at high velocity
  • Lower strength than stainless or duplex alternatives
  • Not suitable for the most aggressive biofouling conditions

FAQ

Yes — for the large majority of standard seawater and brackish cooling water systems at moderate flow velocity, 90/10 provides adequate corrosion and biofouling resistance at a lower cost than 70/30.

There's no single universal threshold — it depends on the specific system design, but as flow velocity increases and erosion-corrosion risk grows, 70/30's higher nickel content provides meaningfully better resistance. Confirm with your corrosion engineer against your specific design velocity.

Yes, 90/10 is typically ex-stock in common diameters given its high demand as the economical default marine alloy — confirm your specific size for immediate availability.

Why Specify With NPRO India

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Every enquiry is checked against governing code, material compatibility and manufacturing feasibility before a quote is issued. Use our product, material, grade and standards guides to freeze the RFQ — then confirm with engineering.

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