On this page 13 sections
What is Cupro-Nickel 90/10?
Quick answer
- Definition
- Cupro-nickel 90/10 (UNS C70600, CuNi10Fe1Mn) is a copper-nickel alloy with iron and manganese, the standard material for seawater piping and condenser tubes because of its corrosion and biofouling resistance.
- Family
- Cupro-Nickel
- Key strength
- Standard for seawater piping
- Main forms
- Pipes, Tubes, Plates, Sheets, Bars, Fittings
- Typical uses
- Ship and offshore seawater piping; Firewater and ballast systems; Condenser and heat-exchanger tubes
90/10 copper-nickel forms a thin, protective surface film in seawater that gives low corrosion rates and natural resistance to marine biofouling. Iron (1.0–1.8%) is essential for erosion resistance at higher flow velocities.
It's used for seawater cooling and firewater piping on ships and offshore platforms, desalination plant brine heaters, condenser tubes, and hydraulic lines. Piping systems are commonly built to EEMUA 144/145/146 for pipe, flanges and fittings. Design flow velocities are typically kept below about 3.5 m/s.
Key characteristics
- Standard for seawater piping
- Natural biofouling resistance
- Iron addition for erosion resistance
- Good weldability and brazability
What are the specifications and equivalents of Cupro-Nickel 90/10?
| Product form | Specification / designation | Product page |
|---|---|---|
| Pipes | ASTM B466 (seamless) / B467 (welded) / EEMUA 144 | Cupro-Nickel 90/10 pipes → |
| Tubes | ASTM B111 / ASME SB111 | Cupro-Nickel 90/10 tubes → |
| Plates | ASTM B171 / B402 | Cupro-Nickel 90/10 plates → |
| Sheets | ASTM B402 | Cupro-Nickel 90/10 sheets → |
| Bars | ASTM B151 | Cupro-Nickel 90/10 bars → |
| Fittings | EEMUA 146 / to order | Cupro-Nickel 90/10 fittings → |
| Flanges | EEMUA 145 / to order | Cupro-Nickel 90/10 flanges → |
UNS C70600 · EN CW352H (cross-reference; limits are similar but not identical)
Standards: ASTM B111, ASTM B466, ASTM B402, ASTM B171, ASTM B151.
What is the chemical composition of Cupro-Nickel 90/10?
| Element | Limit (%) |
|---|---|
| Cu | 86.5 min |
| Ni + Co | 9.0 – 11.0 |
| Fe | 1.0 – 1.8 |
| Mn | 1.0 max |
| Zn | 1.0 max |
| Pb | 0.05 max |
What are the mechanical properties of Cupro-Nickel 90/10?
| Property | Value |
|---|---|
| Tensile strength | 275 MPa (40 ksi) |
| Yield strength (0.2% offset) | 105 MPa (15 ksi) |
Physical properties and service temperature
| Property | Value |
|---|---|
| Density (typical) | 8.94 g/cm³ (8940 kg/m³) |
| Magnetism | Non-magnetic. |
| Heat treatment | Supplied annealed or in the specified temper. |
| Service temperature | — |
How is Cupro-Nickel 90/10 welded and fabricated?
Weldable and brazeable with suitable consumables.
Always follow a qualified welding procedure (for example ASME Section IX) and the filler-metal recommendations for Cupro-Nickel 90/10. Verify incoming material by PMI and check the mill test certificate against the specification.
Which Cupro-Nickel 90/10 products do we supply?
Cupro-Nickel 90/10 is available in 7 product forms, from ready stock or mill-sourced to your specification, with EN 10204 3.1 mill test certificates (3.2 with third-party inspection on request).
Cupro-Nickel 90/10 PlatesASTM B171 / B402Specification & sizes
How it's madeSlabs are hot-rolled on a reversing plate mill (or a Steckel/hot-strip mill for thinner plate), then heat treated (annealed, normalised, or quenched and tempered, depending on material), descaled and pickled or shot-blasted. Plates are cut to size by plasma, oxy-fuel, waterjet or shearing.
- Specification
- ASTM B171 / B402
- Size range
- Thickness about 3 – 150 mm (and heavier on request), widths 1,000 – 3,000 mm, lengths 2,000 – 12,000 mm; cut-to-size and profile-cut parts
- Finish
- No.1 (hot-rolled, annealed and pickled) for stainless; shot-blasted, mill scale or primed for carbon steel
- Ends
- Mill edge, sheared, plasma or waterjet cut, profile cut to drawing
Testing & documents
- Chemical analysis and tensile tests (per plate or heat)
- Impact tests for low-temperature and pressure-vessel plates
- Ultrasonic testing (e.g. ASTM A435 / A578) when specified
- IGC, HIC and simulated PWHT tests as required
- Flatness and dimensional inspection
- EN 10204 3.1 certificate; 3.2 with third-party inspection
Cupro-Nickel 90/10 SheetsASTM B402Specification & sizes
How it's madeHot-rolled coil is cold-rolled to final thickness, then annealed and pickled (2B/2D) or bright annealed (BA), temper-passed, and polished or textured as needed. Coils are then levelled and cut into sheets.
- Specification
- ASTM B402
- Size range
- Thickness about 0.3 – 6 mm, standard sizes 1,000 × 2,000, 1,219 × 2,438 (4 × 8 ft), 1,250 × 2,500 and 1,500 × 3,000 mm; custom cut lengths
- Finish
- 2B, 2D, BA, No.4 (brushed), HL (hairline), No.8 (mirror), embossed, PVC or laser-film protected
- Ends
- Sheared or slit edges; laser-cut blanks on request
Testing & documents
- Chemical and mechanical tests
- Surface and finish inspection
- Thickness and flatness checks
- Hardness and bend tests as specified
- EN 10204 3.1 certificate; 3.2 with third-party inspection
Cupro-Nickel 90/10 BarsASTM B151Specification & sizes
How it's madeBillets are hot-rolled or forged to size, then heat treated (annealed, solution treated, or quenched and tempered) and finished by descaling, peeling, turning, cold-drawing or centreless grinding for bright bar with tight tolerance.
- Specification
- ASTM B151
- Size range
- Round bars about 3 – 500 mm diameter; hex 6 – 100 mm A/F; square and flat sections to order; lengths 3 – 6 m random or cut to size
- Finish
- Black (hot-rolled), peeled, bright drawn, centreless ground and polished (h9 / h11 tolerance)
- Ends
- Saw-cut, chamfered on request
Testing & documents
- Chemical and mechanical tests
- Ultrasonic testing for internal soundness
- Hardness, IGC and impact tests as specified
- Straightness and tolerance checks
- EN 10204 3.1 certificate; 3.2 with third-party inspection
Cupro-Nickel 90/10 FittingsEEMUA 146 / to orderSpecification & sizes
How it's madeButt-weld fittings are formed from seamless or welded pipe or plate by hot or cold forming (mandrel bending, hydraulic bulging, pressing), then heat treated, bevelled and finished. Socket-weld and threaded fittings are machined from forgings or bar.
- Specification
- EEMUA 146 / to order
- Size range
- Butt-weld ½" – 48" (larger fabricated to order) in schedules matching the pipe; socket-weld and threaded ⅛" – 4" in Class 2000, 3000, 6000 and 9000
- Finish
- Annealed & pickled, shot-blasted, black painted or galvanised (by material)
- Ends
- Bevelled (butt-weld), socket-weld, threaded NPT/BSP
Testing & documents
- Chemical and mechanical tests of the starting material
- Dimensional inspection to B16.9 / B16.11
- Radiography of welded fittings (seamed WPW/WX)
- Hardness, IGC and impact tests as specified
- EN 10204 3.1 certificate; 3.2 with third-party inspection
Cupro-Nickel 90/10 FlangesEEMUA 145 / to orderSpecification & sizes
How it's madeFlanges are forged from billets (or cut from plate for some blind and plate flanges), heat treated to the material specification, and machined: bore, face, raised face or ring groove, bolt holes and hub bevel.
- Specification
- EEMUA 145 / to order
- Size range
- NPS ½" – 24" (B16.5), 26" – 60" (B16.47 Series A/B); Class 150, 300, 600, 900, 1500, 2500; EN 1092-1 PN 6 – PN 100 on request
- Finish
- Raised face (RF), flat face (FF) or ring-type joint (RTJ); serrated spiral or concentric face finish (typically 3.2 – 6.3 µm Ra)
- Ends
- Weld-neck bevel matched to pipe schedule; socket bore; threaded
Testing & documents
- Chemical and mechanical tests of the forging
- Dimensional inspection to ASME B16.5 / B16.47
- Hardness, impact and IGC tests as specified
- Ultrasonic testing of forgings on request
- EN 10204 3.1 certificate; 3.2 with third-party inspection
Where is Cupro-Nickel 90/10 used?
Typical applications
- Ship and offshore seawater piping
- Firewater and ballast systems
- Condenser and heat-exchanger tubes
- Desalination brine heaters
- Hydraulic and brake lines
Where do we supply Cupro-Nickel 90/10?
Cupro-Nickel 90/10 is regularly requested for projects in these markets:
What should you specify when buying Cupro-Nickel 90/10?
- Grade and specification, e.g. ASTM B466
- Product form, size and tolerance
- Heat treatment / condition and surface finish
- Quantity, delivery location and required date
- Tests: PMI, hydro/NDT, IGC, impact or hardness as required
- Certificate type (EN 10204 3.1 / 3.2) and third-party inspection
See our RFQ checklist guide and what drives metal prices.
Explore more on Cupro-Nickel 90/10
Cupro-Nickel 90/10 products
Guides
Comparisons & articles
Frequently asked questions
Why is 90/10 cupro-nickel used for seawater?
It combines low corrosion rates, good resistance to biofouling and ease of fabrication, which makes it the standard for ship and offshore seawater systems.
What flow velocity is recommended for 90/10 CuNi pipe?
Design guidance typically limits velocity to around 3.5 m/s in larger pipes (lower in small bores), to avoid erosion-corrosion.
What is Cupro-Nickel 90/10 used for?
Ship and offshore seawater piping, Firewater and ballast systems, Condenser and heat-exchanger tubes, Desalination brine heaters. It's used across Shipbuilding, Marine & Offshore, Desalination, Power Generation.
What is the UNS number of Cupro-Nickel 90/10?
Cupro-Nickel 90/10 is designated UNS C70600; the closest EN cross-reference is CW352H.
Which product forms is Cupro-Nickel 90/10 available in?
Pipes, Tubes, Plates, Sheets, Bars, Fittings, Flanges, to ASTM B466, ASTM B111 / ASME SB111, ASTM B171 / B402 and related specifications.
What is the density of Cupro-Nickel 90/10?
About 8.94 g/cm³ (8940 kg/m³), used for weight calculations.
Is Cupro-Nickel 90/10 magnetic?
Non-magnetic.