C71500 Copper-Nickel 70/30
Mat Grades internal verification confirms source-backed fidelity and data integrity. It does not constitute external certification or guaranteed lot conformity. Read engineering disclaimer →
Key Engineering Properties
Representative source rows, qualified by their reported conditions. Inspect the tables below for all values, limits, and source notes.
Engineering Summary
UNS C71500 Copper-Nickel (70Cu-30Ni with 0.4-1.0% Fe) delivers superior strength and erosion-corrosion resistance in severe high-velocity seawater. Widely used by naval defense forces for nuclear submarine piping, desalination heat exchangers, and high-pressure marine hydraulic systems.
C71500 Copper-Nickel 70/30 Documented Applications
- ›Boiler Parts: Corrosion Resistance
- ›Boiler Parts: Welding Characteristics
- ›Condenser Components: Corrosion Resistance
- ›Condenser Components: Forming Characteristics
- ›Condenser Components: Mechanical Properties
- ›Condenser Plates: Corrosion Resistance
- ›Condenser Plates: Forming Characteristics
- ›Condenser Plates: Mechanical Properties
- ›Condensers: Corrosion Resistance
- ›Condensers: Mechanical Properties
- ›Distiller Tubes: Corrosion Resistance
- ›Distiller Tubes: Forming Characteristics
Recognized Aliases
Source-backed commercial trade name and short designations cataloged in canonical data.
C71500 Copper-Nickel 70/30 Specifications & Designations
Standard Designations & Applicable Specifications — Semantically classified designations distinguishing primary standard identifiers, commercial trade names, and applicable specification references.
| System | Identifier | Standard System Name | Classification Notes & Provenance |
|---|---|---|---|
| UNSPRIMARY | C71500 | Unified Numbering System | Unified Numbering System standard designation for copper alloys (CDA / SAE / ASTM)Ref: CDA UNS Standard Designations Register (C71500) |
| CDA | Alloy 715 | Copper Development Association Alloy Number | CDA three-digit legacy designationRef: CDA UNS Standard Designations Register (C71500) |
| Recognized Name / Alias | Classification | Technical Usage & Context |
|---|---|---|
| 70/30 Cupronickel | Standard Commercial Name | CDA Standard Commercial Name |
| Copper-Nickel 70/30 | Commercial Alias | Colloquial or commercial industry synonym |
| Cupronickel 70-30 | Commercial Alias | Colloquial or commercial industry synonym |
| C71500 | Commercial Alias | Colloquial or commercial industry synonym |
| Standards Body | Specification Code | Specification Title / Scope | Relationship Type |
|---|---|---|---|
| SAE | SAE J461 | WROUGHT AND CAST COPPER ALLOYS | Specification Reference |
| ASTM | ASTM B122/B122M | COPPER-NICKEL-ZINC ALLOY (NICKEL-SILVER) AND COPPER-NICKEL PLATE, SHEET, STRIP, AND ROLLED BAR | Specification Reference |
| MILITARY | MILITARY MIL-C-15726 | COPPER-NICKEL ALLOY ROD, FLAT PRODUCTS (FLAT WIRE, STRIP, SHEET, BAR, AND PLATE) AND FORGINGS | Specification Reference |
| SAE | SAE J463 | WROUGHT COPPER AND COPPER ALLOYS | Specification Reference |
| ASTM | ASTM F468 | NONFERROUS BOLTS, HEX CAP SCREWS, AND STUDS FOR GENERAL USE | Specification Reference |
| ASTM | ASTM B956/B956M | WELDED COPPER AND COPPER-ALLOY CONDENSER AND HEAT EXCHANGER TUBES WITH INTEGRAL FINS | Specification Reference |
| AWS | AWS A5.6 | COPPER AND COPPER ALLOY COVERED ELECTRODES | Specification Reference |
| MILITARY | MILITARY MIL-E-22200/4 | ELECTRODES, WELDING, COVERED, COPPER-NICKEL ALLOY | Specification Reference |
| ASTM | ASTM F467 | NONFERROUS NUTS FOR GENERAL USE | Specification Reference |
| ASTM | ASTM B466/B466M | SEAMLESS COPPER-NICKEL PIPE AND TUBE | Specification Reference |
| ASME | ASME SB467 | WELDED COPPER-NICKEL PIPE | Specification Reference |
| ASTM | ASTM B467 | WELDED COPPER-NICKEL PIPE | Specification Reference |
C71500 Copper-Nickel 70/30 Chemical Composition
Chemical Composition (Weight %) — Elemental limits and values from the cited source. Preserves exact semantic limits (minimums, maximums, and ranges).
| Element | Symbol | Atomic No. | Semantic Basis | Specified Value | Unit | Metallurgical Notes & Qualification | Data Status |
|---|---|---|---|---|---|---|---|
| Copper | Cu | 29 | BALANCE | Balance | wt% | Remainder element (Copper).Ref: Copper Development Association (CDA) | VERIFIED |
| Lead | Pb | 82 | MAXIMUM | ≤ 0.05 | wt% | CDA chemical composition specification limits for C71500: max 0.05 wt%.Ref: Copper Development Association (CDA) | VERIFIED |
| Zinc | Zn | 30 | MAXIMUM | ≤ 1.00 | wt% | CDA chemical composition specification limits for C71500: max 1.0 wt%.Ref: Copper Development Association (CDA) | VERIFIED |
| Iron | Fe | 26 | RANGE | 0.40 – 1.00 | wt% | CDA chemical composition specification limits for C71500: 0.4 - 1.0 wt%.Ref: Copper Development Association (CDA) | VERIFIED |
| Nickel | Ni | 28 | RANGE | 29.00 – 33.00 | wt% | CDA chemical composition specification limits for C71500: 29.0 - 33.0 wt%.Ref: Copper Development Association (CDA) | VERIFIED |
| Manganese | Mn | 25 | MAXIMUM | ≤ 1.00 | wt% | CDA chemical composition specification limits for C71500: max 1.0 wt%.Ref: Copper Development Association (CDA) | VERIFIED |
C71500 Copper-Nickel 70/30 Physical Properties
Source-specific physical properties. Test temperatures are shown only where reported.
| Property Parameter | Canonical SI Value | Semantic Basis | Test Temperature / Context Range | Source Raw Reference | Source Reference | Status |
|---|---|---|---|---|---|---|
| Density | 8.941 g/cm³ | TYPICAL | Test Temp: 20 °CCDA Physical Properties: Density 0.323 lb/cu in. at 68°F (8.941 g/cm³ at 20°C) | 0.323 lb/cu in. at 68°F | Copper Development Association Inc. | VERIFIED |
C71500 Copper-Nickel 70/30 Thermal & Thermodynamic Properties
Phase change temperatures, thermal conductivity, specific heat, mean coefficients of thermal expansion across standardized temperature ranges, and recommended thermal processing windows.
| Property Parameter | Canonical SI Value | Semantic Basis | Test Temperature / Context Range | Source Raw Reference | Source Reference | Status |
|---|---|---|---|---|---|---|
| Liquidus Temperature | 1237.8 °C | TYPICAL | CDA Physical Properties: Liquidus temperature 2260.0 °F (1237.8 °C) | 2260.0 °F | Copper Development Association Inc. | VERIFIED |
| Solidus Temperature | 1171.1 °C | TYPICAL | CDA Physical Properties: Solidus temperature 2140.0 °F (1171.1 °C) | 2140.0 °F | Copper Development Association Inc. | VERIFIED |
| Thermal Conductivity | 29.42 W/(m·K) | TYPICAL | Test Temp: 20 °CCDA Physical Properties: Thermal conductivity 17.0 Btu/(ft·hr·°F) (29.42 W/(m·K) at 20°C) | 17.0 Btu/ sq ft/ ft hr/ °F at 68°F | Copper Development Association Inc. | VERIFIED |
| Coefficient of Thermal Expansion (CTE) | 16.2 µm/(m·K) | TYPICAL | CDA Physical Properties: CTE 9.0 µin/(in·°F) (16.2 µm/(m·K)) over range 68-57210°F | 9.0 10^-6 per °F | Copper Development Association Inc. | VERIFIED |
| Specific Heat Capacity | 376.8 J/(kg·K) | TYPICAL | Test Temp: 20 °CCDA Physical Properties: Specific heat 0.09 Btu/(lb·°F) (376.8 J/(kg·K)) | 0.09 Btu/ lb /°F at 68°F | Copper Development Association Inc. | VERIFIED |
| Annealing Temperature Range | 648.9 – 815.6 °C | RANGE | CDA Thermal Treatments: Annealing temperature range 1200 - 1500°F (648.9 - 815.6°C) | 1200 – 1500 °F | Copper Development Association Inc. | VERIFIED |
| Hot Working Temperature Range | 926.7 – 1037.8 °C | RANGE | CDA Thermal Treatments: Hot working range 1700 - 1900°F (926.7 - 1037.8°C) | 1700 – 1900 °F | Copper Development Association Inc. | VERIFIED |
C71500 Copper-Nickel 70/30 Electrical Properties
Electrical conductivity and resistivity in their reported units and conditions.
| Property Parameter | Canonical SI Value | Semantic Basis | Test Temperature / Context Range | Source Raw Reference | Source Reference | Status |
|---|---|---|---|---|---|---|
| Electrical Conductivity | 4.6 % IACS | TYPICAL | Test Temp: 20 °CCDA Physical Properties: Volume conductivity 4.6 % IACS at 68°F (20°C) | 4.6 % IACS at 68°F | Copper Development Association Inc. | VERIFIED |
C71500 Copper-Nickel 70/30 Mechanical Properties
Contextual Mechanical Properties & Tempers: Engineering strength, ductility, and hardness values grouped by product form, temper, and section thickness. Mechanical properties are contextual and not isotropic averages.
| Product Form | Temper / Condition | Section Size | Tensile (UTS) | Yield Strength | Elongation | Shear Strength | Fatigue Strength | Hardness (Scales Preserved) | Status |
|---|---|---|---|---|---|---|---|---|---|
| Flat Products | As Hot Rolled (M20) · 20 °CSource values and qualifiersTensile Strength: 379.2 MPa (TYPICAL)Section Size: 1; Section Size: 1 inCopper Development Association (CDA) — Elongation: 45 % (TYPICAL)Section Size: 1; Section Size: 1 inCopper Development Association (CDA) — | 1 | 379.2 MPa | — | 45 % | — | — | — | VERIFIED |
| Flat Products | As Hot Rolled (M20)Source values and qualifiersRockwell B Hardness: 35 HRB (TYPICAL)Section Size: 1; Section Size: 1 inCopper Development Association (CDA) — | 1 | — | — | — | — | — | 35 HRB | VERIFIED |
| Rod | 1/2 Hard (H02) · 20 °CSource values and qualifiersTensile Strength: 517.1 MPa (TYPICAL)Section Size: 1; Cold Work: 20%; Section Size: 1 inCopper Development Association (CDA) — Elongation: 15 % (TYPICAL)Section Size: 1; Cold Work: 20%; Section Size: 1 inCopper Development Association (CDA) — | 1 | 517.1 MPa | — | 15 % | — | — | — | VERIFIED |
| Rod | 1/2 Hard (H02)Source values and qualifiersRockwell B Hardness: 80 HRB (TYPICAL)Section Size: 1; Cold Work: 20%; Section Size: 1 inCopper Development Association (CDA) — | 1 | — | — | — | — | — | 80 HRB | VERIFIED |
| Tube | Nominal Grain Size 0.025 mm (OS025) · 20 °CSource values and qualifiersTensile Strength: 413.7 MPa (TYPICAL)Copper Development Association (CDA) — Elongation: 45 % (TYPICAL)Copper Development Association (CDA) — | — | 413.7 MPa | — | 45 % | — | — | — | VERIFIED |
| Tube | Nominal Grain Size 0.025 mm (OS025)Source values and qualifiersRockwell B Hardness: 45 HRB (TYPICAL)Copper Development Association (CDA) — Rockwell F Hardness: 80 HRF (TYPICAL)Copper Development Association (CDA) — | — | — | — | — | — | — | 45 HRB80 HRF | VERIFIED |
| Tube | Nominal Grain Size 0.035 mm (OS035) · 20 °CSource values and qualifiersTensile Strength: 372.3 MPa (TYPICAL)Copper Development Association (CDA) — Elongation: 45 % (TYPICAL)Copper Development Association (CDA) — | — | 372.3 MPa | — | 45 % | — | — | — | VERIFIED |
| Tube | Nominal Grain Size 0.035 mm (OS035)Source values and qualifiersRockwell B Hardness: 36 HRB (TYPICAL)Copper Development Association (CDA) — Rockwell F Hardness: 77 HRF (TYPICAL)Copper Development Association (CDA) — | — | — | — | — | — | — | 36 HRB77 HRF | VERIFIED |
C71500 Copper-Nickel 70/30 Processing & Fabrication
Machining, joining, forming, and thermal processing ratings cataloged from the cited authoritative technical reference.
Machinability
Machinability rating: 20% relative to free-cutting brass (C36000 = 100%).
Weldability & Joining
Soldering: Excellent; Brazing: Excellent; Oxyacetylene Welding: Good; Gas Shielded Arc Welding: Excellent; Coated Metal Arc Welding: Excellent; Spot Weld: Excellent; Seam Weld: Excellent; Butt Weld: Excellent
Heat Treatment & Working Ranges
Annealing temperature range: 648.9°C to 815.6°C (1200°F - 1500°F). Hot working temperature range: 926.7°C to 1037.8°C (1700°F - 1900°F).
Forming & Cold Working
Capacity for Being Cold Worked: Good. Capacity for Being Hot Formed: Good.
Practical Engineering & Fabrication Notes
By Mat Grades Editorial Desk · Updated 2026-11-14. Use alongside the specified product standard and supplier certificate.
Machining & shop-floor behavior
The cataloged machining note for C71500 Copper-Nickel 70/30 states: Machinability rating: 20% relative to free-cutting brass (C36000 = 100%). A relevant hardness example is Rockwell B Hardness: 35 HRB (typical; As Hot Rolled (M20), M20, Flat Products, 1). Use that supplied condition for a trial of the difficult feature. Record tool changes, burr removal, unclamped dimensions and accepted parts per hour. Relative machinability ratings from different reference scales should not be compared as if they were one common test.
Weldability, brazing & joining
The available joining assessment states: Soldering: Excellent; Brazing: Excellent; Oxyacetylene Welding: Good; Gas Shielded Arc Welding: Excellent; Coated Metal Arc Welding: Excellent; Spot Weld: Excellent; Seam Weld: Excellent; Butt Weld: Excellent The first cataloged strength example is Tensile Strength: 379.2 MPa (typical; As Hot Rolled (M20), M20, Flat Products, 1; test temperature 20 °C). Assess the final part after joining or thermal processing. Include distortion, cleanup and inspection in the quotation. A material designation or favorable process rating is a starting point for qualification, not evidence that an untested joint meets the drawing.
Corrosion & service environment
Review the working fluid, cleaning agents and dissimilar-metal contacts as separate exposures. The word copper, brass or bronze is too broad to establish compatibility. A process rating does not qualify a pressure boundary, and a thermal-property measurement does not establish a continuous service-temperature limit. The recorded thermal example is Thermal Conductivity: 29.42 W/(m·K) (typical; ; test temperature 20 °C). State the exposure and inspection access in the design record so that a change of installation or cleaning method triggers a review. The selected composition entries are Pb maximum 0.05 wt%, Zn maximum 1 wt%. Chemistry documents identity; it does not establish fluid compatibility.
Selection trade-offs & applications
Use UNS C71500, COMMERCIAL 70/30 Cupronickel, CDA Alloy 715 to identify the candidate, then specify the product form and delivered condition separately. The catalog lists Boiler Parts: Corrosion Resistance as an application example. The related candidate C70600 Copper-Nickel 90/10 is linked for comparison; its commonly compared relationship must be checked before substitution. Compare the complete route through machining, joining, finish and inspection. Keep the certificate, required test location and acceptance criteria with the first-article record. A later change of grade, condition or source should be assessed against that same requirement.
Technical references: Copper Development Association (CDA); Copper Development Association (CDA)
C71500 Copper-Nickel 70/30 Equivalent & Comparable Grades
Comparable Grades & Cross-References: Carefully classified cross-reference relationships for C71500 Copper-Nickel 70/30. Comparable does not mean equivalent.
| Related Material | Family | Relationship Classification | Metallurgical Notes & Differences | Status | Action |
|---|---|---|---|---|---|
| C70600 Copper-Nickel 90/10 | Copper Alloys | Commonly Compared | C71500 (70/30 Cu-Ni) provides greater erosion-corrosion resistance and allowable stress in marine piping systems, while C70600 (90/10) offers high biofouling resistance and lower material cost.Materials serve different design priorities (e.g. higher strength vs superior corrosion resistance or cost). | VERIFIED |
Copper-Nickel (Cupronickel) Alloy Family
Copper alloys sharing common alloying formulations and metallurgical classifications under the Copper-Nickel (Cupronickel) branch.
Sources
Sources & Provenance Trail: Authoritative reference publications, standards specifications, and data registers cited across this material record.
Copper Development Association authoritative technical reference profile for C71500 Copper-Nickel 70/30.
Unified Numbering System (UNS) designation registration register confirming active C71500 status.