What is C70600 Copper Nickel (90/10) Alloy?
C70600, also known as Copper Nickel 90/10, CuNi10Fe1Mn, or ASTM B111 C70600, is a copper-nickel alloy made up of approximately 10% nickel with controlled quantities of iron and manganese. This combination provides extraordinary resistance to general corrosion, stress cracking, erosion, and impingement – especially from turbulent water containing air bubbles and silt flowing at high velocities.
C70600 is known for its moderate strength, excellent weldability, and good formability, making it the top choice for marine and seawater applications.
What are the Equivalent Designations and Specifications for C70600?
GNEE supplies C70600 to meet all major global standards. Use this table for cross-referencing.
| Standard | Equivalent / Specification |
|---|---|
| ASTM | B151, B466, B111, B171, B122/B122M, B956/B956M, B467, B432 |
| ASME | SB466, SB111, SB151, SB171, SB467, SB359 |
| DIN | 2.0872 |
| BS | 2871 CN102 |
| EN | CW352H |
| SAE | J461, J463 |
| MIL | C-1726F, C-24679, T-16420K, C-15726, T-15005, T-22214 |
Common names: CuNi10Fe1Mn, 90/10 Cu-Ni, Copper Nickel 90/10, ASTM B466 C70600.
What is the Chemical Composition of C70600 (90/10 Copper Nickel)?
| Element | Min % | Max % |
|---|---|---|
| Copper (Cu) | Remaining | Remaining |
| Nickel (Ni) | 9.0 | 11.0 |
| Iron (Fe) | 1.0 | 1.8 |
| Manganese (Mn) | – | 1.0 |
| Lead (Pb) | – | 0.05 |
| Zinc (Zn) | – | 1.0 |
What are the Physical Properties of C70600 Tube and Bar?
| Property | Imperial |
|---|---|
| Melting Point – Liquidus | 2100 °F |
| Melting Point – Solidus | 2010 °F |
| Density (at 68°F) | 0.323 lb/in³ |
| Specific Gravity | 8.94 |
| Electrical Conductivity (at 68°F) | 9% IACS |
| Thermal Conductivity (at 68°F) | 26 Btu/sq ft/ft hr/°F |
| Coefficient of Thermal Expansion (68-212°F) | 9.5 x 10⁻⁶ per °F |
| Modulus of Elasticity (Tension) | 18,000 ksi |
| Modulus of Rigidity | 6,800 ksi |
What are the Mechanical Properties of C70600 (90/10 Cu-Ni)?
| Form | Temper | Tensile Strength (ksi) | Yield Strength 0.2% Offset (ksi) | Elongation (%) | Hardness |
|---|---|---|---|---|---|
| Round Bar / Rod | H04 | 50 | 25 | 15 | – |
| Round Bar / Rod | O60 | 38 | 15 | 30 | – |
| Plate / Sheet / Strip | H01 | 53 | 16 | 35 | 60 (RB) |
| Plate / Sheet / Strip | H04 | 75 | 73 | 5 | 80 (RB) |
| Tube | O61 | 44 | 16 | 42 | 15 (RB) / 65 (RF) |
| Tube | H55 | 45 | 35 | 10 | 72 (RB) / 100 (RF) |
C70600 tube in annealed temper (O61) offers 42% elongation – ideal for bending and flaring.
What Fabrication Methods are Suitable for C70600?
| Technique | Suitability for C70600 |
|---|---|
| Soldering | Excellent |
| Brazing | Excellent |
| Oxyacetylene Welding | Fair |
| Gas Shielded Arc Welding | Excellent |
| Coated Metal Arc Welding | Good |
| Spot Weld | Good |
| Seam Weld | Good |
| Butt Weld | Excellent |
| Cold Forming | Good |
| Hot Forming | Good |
| Machinability Rating | 20 (UNS C36000 = 100) |
What are the Common Applications for C70600 (90/10 Copper Nickel)?
GNEE supplies C70600 for these demanding applications:
Desalination plants – tubing and fittings
Underwater tubing – seawater intake/outfall lines
Heat exchangers – condenser tubes (ASTM B111)
Marine hardware – boat hulls, propeller sleeves
Automotive – coolant lines
Industrial – hydraulic lines, instrumentation tubing
Plumbing – potable water systems
What Product Shapes are Available for C70600 from GNEE?
| Shape | Size Range |
|---|---|
| Round Bar | 3/8" dia to 11" |
| Plate | 3/16" thick to 3" |
| Sheet | 0.065", 0.125" |
| Tube | 3/8" OD to 1" |
| Pipe | 1/4" Sch 40 to 12" Sch 80; Class 200 MIL-T-16420K to 12" |
| Fittings | Class 200, Sch 40, Sch 80, Buttweld, Threaded, Socketweld (3000#/6000#) |
| Flanges | Slip-on, threaded, blind, weldneck |
FAQ
Q1: What is the difference between C70600 (90/10 Cu-Ni) and C71500 (70/30 Cu-Ni) for tube applications?
A: C70600 (90/10 Copper Nickel) contains 10% nickel and is more cost-effective. C71500 (70/30 Copper Nickel) contains 30% nickel, offering higher strength and better erosion resistance in very high-velocity seawater. For most marine piping, C70600 tube is sufficient.
Q2: What is the European equivalent to ASTM B111 C70600 seamless tube?
A: The European equivalent to ASTM B111 C70600 is EN CW352H (CuNi10Fe1Mn) and DIN 2.0872.
Q3: Can ASTM B151 C70600 round bar be welded to stainless steel?
A: Yes, C70600 bar can be welded to stainless steel using ERNiCu-7 or AWS A5.7 ERCuNi filler metals. However, galvanic corrosion protection is recommended in seawater service.
Q4: What is the maximum operating temperature for ASTM B111 C70600 condenser tube?
A: C70600 tube can operate continuously up to 300°C (572°F) in heat exchanger service. Above this temperature, strength decreases significantly.
Q5: Does ASME SB111 C70600 tube require post-weld heat treatment?
A: No, C70600 tube typically does not require post-weld heat treatment. Stress relief annealing at 593-816°C may be used for heavily welded sections.
Q6: How does the corrosion resistance of C70600 (90/10 Cu-Ni) compare to 316L stainless steel in seawater?
A: C70600 offers superior resistance to chloride stress-corrosion cracking compared to 316L stainless steel. In stagnant or low-velocity seawater, 316L can pit, while C70600 performs reliably.
Q7: What filler metal should be used for TIG welding C70600 tube to itself?
A: For TIG welding C70600 tube, use AWS A5.7 ERCuNi filler metal. It matches the alloy composition and provides good corrosion resistance.
Q8: What is the machinability rating of ASTM B466 C70600 pipe?
A: C70600 pipe has a machinability rating of 20 (UNS C36000 free-cutting brass = 100). Use sharp carbide tools and ample coolant.
Q9: Can C70600 (90/10 Copper Nickel) be used for seawater piping systems?
A: Yes, C70600 is one of the most popular materials for seawater piping on ships, offshore platforms, and desalination plants due to its excellent biofouling and corrosion resistance.
Q10: What temper of C70600 tube is best for bending?
A: Annealed temper (O61) C70600 tube offers 42% elongation and is best for bending and flaring. Hard temper (H55) is for straight runs where higher strength is needed.
Q11: Is C70600 (90/10 Copper Nickel) compatible with potable water systems?
A: Yes, C70600 is approved for potable water systems. Its corrosion resistance prevents copper leaching within acceptable limits.
Q12: What is the difference between ASTM B111 C70600 and ASTM B466 C70600?
A: ASTM B111 C70600 covers seamless tubes for heat exchangers and condensers. ASTM B466 C70600 covers seamless pipe for general piping systems. Both are C70600 alloy.
Q13: Can C70600 round bar be cold headed?
A: Yes, C70600 round bar has good cold forming capacity. Annealed temper (O60) is recommended for cold heading.
Q14: What is the thermal conductivity of C70600 sheet compared to pure copper?
A: C70600 sheet has a thermal conductivity of 26 Btu/sq ft/ft hr/°F, which is about 9% IACS. Pure copper (C11000) is 100% IACS, so C70600 conducts less heat – an advantage in some heat exchanger designs.
Q15: How is ASTM B111 C70600 tube inspected at GNEE?
A: Each C70600 tube undergoes chemical analysis, tensile testing, flattening test, expansion test, hydrostatic or eddy current testing, and dimensional inspection. Mill test reports (MTR) are traceable to heat number.
Quality Inspection for C70600 (90/10 Copper Nickel)
Every batch of C70600 supplied by GNEE undergoes:
| Test | Standard / Method |
|---|---|
| Chemical composition | Spectrometer (ARL iSpark) |
| Tensile strength | ASTM E8 / E8M |
| Yield strength (0.2% offset) | ASTM E8 |
| Elongation | ASTM E8 |
| Flattening test (tube) | ASTM B111 |
| Expansion test (tube) | ASTM B111 |
| Hydrostatic test (tube/pipe) | ASTM B111 / B466 |
| Eddy current test (tube) | ASTM E243 |
| Hardness (Rockwell) | ASTM E18 |
| Dimensional inspection | Micrometer / caliper |
| Visual inspection | Naked eye / borescope |
All tests documented with heat number traceable Mill Test Reports (MTR).
Third-party inspection (SGS, BV, TUV) available upon request.
Packaging for ASTM B111 C70600 Copper Nickel Tube
| Step | Packaging Action |
|---|---|
| 1 | Clean and dry tube interior/exterior |
| 2 | Apply plastic end caps on both ends |
| 3 | Wrap each tube with VCI paper |
| 4 | Bundle tubes in hexagonal packs |
| 5 | Secure with rust-proof steel strapping (2-4 straps) |
| 6 | Wrap bundle with woven polypropylene fabric or PE film |
| 7 | Place in wooden crates or on plywood pallets |
| 8 | Attach shipping marks (alloy, size, heat number, quantity) |
Packaging options for C70600 tube:
| Type | Suitable For |
|---|---|
| Hexagonal bundle + woven bag | Standard export (dry container) |
| VCI paper + wooden crate | High-value / polished tubes |
| Shrink-wrapped + palletized | Small diameter tubes |
| Single tube + foam + crate | Critical applications |
Factory Equipment (GNEE Manufacturing Facility for Copper Alloys)
| Equipment | Function |
|---|---|
| 30T Induction Furnace | Melting and alloying |
| Horizontal Continuous Caster | Producing solid and hollow billets |
| Extrusion Press (2500T) | Forming tubes and profiles |
| Cold Drawing Bench (5-120mm) | Precision tube/bar drawing |
| Roller Straightening Machine | Straightening bars and tubes |
| Annealing Furnace (protective atmosphere) | Heat treatment |
| Eddy Current Tester | Non-destructive testing |
| Spectrometer (ARL iSpark) | Chemical analysis |
| Universal Testing Machine | Mechanical property testing |
Product Range
GNEE supplies a full range of copper and copper alloy products. C70600 is available in all forms below:
| Product Category | Examples / Specifications |
|---|---|
| Copper-Nickel Alloys | C70600 (90/10), C71500 (70/30), CuNi30Fe, CuNi10Fe1Mn |
| Copper Tubes | ASTM B280 (ACR), ASTM B88 (water), EN 1057, ASTM B111 (condenser) |
| Brass Products | C26000 (cartridge brass), C36000 (free-cutting brass), C37700 (forging brass) |
| Bronze Products | C51000 (phosphor bronze), C52100, C54400 |
| Copper Bars / Rods | C10100 (OFC), C11000 (ETP), C12200 (DHP) |
| Copper Plates / Sheets | C11000, C12200, C70600, C71500 |
| Copper Wire | C11000 bare wire, tinned copper wire |
| Copper Pipe & Fittings | C70600, C71500, C12200 – various schedules |
| Custom Forgings & Castings | Per drawing or specification |
GNEE offers custom sizes, tempers, and third-party inspection (SGS/BV/TUV).
Contact GNEE for a quote on C70600 tube, bar, plate, or fittings.
