Copper Alloy C71580
UNS C71580
C71580 (CuNi30Fe) is a modified 70/30 copper-nickel with adjusted iron and manganese levels for improved castability and weldability, supplied in M20, O61, OS025, H55, HR50, H80 and as-welded conditions.
Reference datasheet — C71580 is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the O61 condition
C71580 tempers and conditions
C71580 is supplied in 7 conditions, soft to hard. O61 is the default FabDigit quotes; the values on this page are for it.
Compare all 7 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
O61Default Annealed | Default stock condition for plate, tube, bar and fittings — maximum ductility for forming, expanding and welding. | 150 | 380 | 42 | 80 HB | 4.6 % IACS |
Annealed to 0.025 mm grain size | Grain-size-controlled anneal for sheet/strip that must be deep drawn or spun with a fine, uniform surface finish. | 165 | 395 | 40 | 85 HB | 4.6 % IACS |
As hot rolled | Plate and heavy bar in the as-hot-worked state; used for weld-fabricated tube sheets and pressure parts where a stress-relief anneal is not required. | 170 | 400 | 38 | 85 HB | 4.6 % IACS |
As-welded deposit | Properties of undiluted deposited weld metal when the grade is supplied as CuNi filler rod or wire for joining 70/30 and 90/10 CuNi. | 220 | 400 | 30 | 90 HB | 4.4 % IACS |
Light drawn | Light cold-drawn condensor/heat-exchanger tube — straighter and stiffer than annealed while still expandable into tube sheets. | 275 | 450 | 25 | 115 HB | 4.5 % IACS |
Drawn and stress-relieved | Cold-drawn then low-temperature stress relieved — higher proof strength with reduced residual stress for pressure tube and shafting. | 380 | 480 | 20 | 130 HB | 4.5 % IACS |
Hard drawn | Heavily cold-worked rod, wire and tube for maximum strength and wear resistance; very limited remaining ductility. | 540 | 585 | 8 | 170 HB | 4.5 % IACS |
What is C71580?
C71580 (CuNi30Fe) is a modified 70/30 copper-nickel with adjusted iron and manganese levels for improved castability and weldability, supplied in M20, O61, OS025, H55, HR50, H80 and as-welded conditions. It is used for fittings, flanges and hardware paired with C71500 piping, offering 380 MPa tensile, 150 MPa yield, 42 % elongation, 80 HB and a formability score of 85. Thermal conductivity is 29 W/m·K, electrical conductivity 4.6 % IACS and the service limit is 350 °C; stock is limited and machining is slow, so standard C71500 product forms are the usual substitute. C71580 has a density of 8.94 g/cm³ (0.323 lb/in³), heavier than 90% of copper alloy grades. It melts at 1,170°C (2,138 °F). C71580 has a yield strength of 150 MPa (21.8 ksi) and a tensile strength of 380 MPa (55.1 ksi) — weaker than 69% of copper alloy grades. Elongation at break is 42% and the elastic modulus is 152 GPa (22 Msi).
What is C71580 used for?
- pipe fittings
- flanges
- marine hardware
Advantages
- Stiff — 152 GPa (22 Msi), better than 99% of copper alloy grades
- Good corrosion resistance — 82/100, better than 98% of copper alloy grades
- Readily welded — 88/100, better than 97% of copper alloy grades
- High service temperature — 350°C (662 °F), better than 95% of copper alloy grades
- Ductile — tolerates forming and impact — 42%, better than 86% of copper alloy grades
Limitations
- Low electrical conductivity — 4.6 % IACS, worse than 96% of copper alloy grades
- High embodied carbon — 6.5 kg CO₂/kg, worse than 94% of copper alloy grades
- Poor heat conductor — 29 W/m·K (16.8 BTU/hr·ft·°F), worse than 93% of copper alloy grades
C71580 properties
Typical room-temperature values for C71580-O61; bars are the position among copper alloy grades.
Physical3
C71580 has a density of 8.94 g/cm³ (0.323 lb/in³), heavier than 90% of copper alloy grades. It melts at 1,170°C (2,138 °F).
Mechanical14
C71580 has a yield strength of 150 MPa (21.8 ksi) and a tensile strength of 380 MPa (55.1 ksi) — weaker than 69% of copper alloy grades. Elongation at break is 42% and the elastic modulus is 152 GPa (22 Msi).
Thermal6
C71580 is rated for continuous service to 350°C (662 °F). It conducts heat at 29 W/m·K (16.8 BTU/hr·ft·°F), worse than 93% of copper alloy grades. Thermal expansion is 16.2 µm/m·K (9 µin/in·°F).
Electrical3
C71580 conducts electricity at 4.6 % IACS, worse than 96% of copper alloy grades.
Chemical & Environmental3
Corrosion resistance is very good (82/100), better than 98% of copper alloy grades.
Sustainability4
Producing a kilogram of C71580 takes about 88 MJ of energy and emits 6.5 kg of CO₂ — more than 92% of copper alloy grades. Typical recycled content is 30%.
Manufacturability8
C71580's machinability is poor (28/100, worse than 78% of copper alloy grades); weldability excellent (88/100); formability excellent (85/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the copper alloy family
Yield strength against density for every copper alloy grade FabDigit runs. C71580 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with C71580
Is C71580 easy to machine?
Gummy and work-hardening — use positive-rake sharp carbide, heavy feeds, low-to-moderate speed (~40–70 m/min) and generous coolant; avoid dwelling.
Can C71580 be welded?
GTAW/GMAW with matching CuNi (ERCuNi/ENiCu type) filler, no preheat, low interpass (<150 °C), clean oxide-free joints — sulphur and lead contamination causes hot cracking.
Can C71580 be formed, bent or molded?
Excellent cold formability in O61; springback is high, and interanneal near 700–850 °C followed by rapid cooling after ~50 % reduction.
C71580 chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| NiNi + Co counted together in most registrations | 29 – 33 | 30.5 |
| Feiron level trimmed vs C71500 for weld/casting soundness | 0.4 – 1 | 0.7 |
| Mndeoxidiser / sulphur scavenger | 0.3 – 1 | 0.6 |
| Zn | ≤ 0.05 | |
| Pb | ≤ 0.02 | |
| C | ≤ 0.05 | |
| S | ≤ 0.02 | |
| P | ≤ 0.02 | |
| Si | ≤ 0.25 | |
| Curemainder; confirm exact registered limits against the current CDA/ASTM chemistry sheet for C71580 | balance |
What surface finishes work on C71580?
Takes a good buffed finish; not anodisable — passivate, tin/nickel plate, or develop the protective seawater film with ferrous-sulphate dosing during commissioning.
Surface treatments FabDigit runs on copper alloy parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
Equivalent designations
Standards and trade names that resolve to Copper Alloy C71580 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- Also called
- CuNi30
- Similar grades
- CuNi30Fe
How much does C71580 cost?
C71580 is a high-cost copper alloy ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
C71580 — frequently asked
What is C71580 used for?
C71580 is typically used for pipe fittings, flanges and marine hardware. In short: fitting-grade 70/30 Cu-Ni; weld-friendly CuNi30Fe; pairs with C71500 piping.
What is the yield strength of C71580?
C71580 has a typical yield strength of 150 MPa (21.8 ksi) and a tensile strength of 380 MPa (55.1 ksi) — weaker than 69% of copper alloy grades. Strength varies by condition: see the 7 listed tempers.
Is C71580 easy to machine?
Not especially — machinability is rated poor (28/100, worse than 78% of copper alloy grades). Gummy and work-hardening — use positive-rake sharp carbide, heavy feeds, low-to-moderate speed (~40–70 m/min) and generous coolant; avoid dwelling.
Can C71580 be welded?
Yes — weldability is rated excellent (88/100). GTAW/GMAW with matching CuNi (ERCuNi/ENiCu type) filler, no preheat, low interpass (<150 °C), clean oxide-free joints — sulphur and lead contamination causes hot cracking.
What surface finishes work on C71580?
Takes a good buffed finish; not anodisable — passivate, tin/nickel plate, or develop the protective seawater film with ferrous-sulphate dosing during commissioning.
Can C71580 be formed, bent or molded?
Excellent cold formability in O61; springback is high, and interanneal near 700–850 °C followed by rapid cooling after ~50 % reduction.
What is the maximum service temperature of C71580?
C71580 is rated for continuous use to about 350°C (662 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between C71580-O61 and C71580-H80?
O61 is the default condition — default stock condition for plate, tube, bar and fittings — maximum ductility for forming, expanding and welding. H80: heavily cold-worked rod, wire and tube for maximum strength and wear resistance; very limited remaining ductility. Yield strength is 150 MPa in O61 versus 540 MPa in H80.
How much does C71580 cost?
C71580 is a high-cost copper alloy ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Sources
- CDA/UNS Copper Alloy Data — 70/30 Copper-Nickel family — Copper Development Association (2023)
- ASTM B466/B466M — Seamless Copper-Nickel Pipe and Tube — ASTM (2020)
- ASTM B171/B171M — Copper-Alloy Plate and Sheet for Condensers and Heat Exchangers — ASTM (2018)
- AWS A5.7/A5.7M — Copper and Copper-Alloy Bare Welding Rods and Electrodes — AWS (2011)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
- Guide to Copper-Nickel Alloys for Seawater Service — Nickel Institute / CDA (2018)
- GB/T 2040 / GB/T 8890 — SAC (2017)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.