Copper Alloy C70700
UNS C70700
C70700 is a 90/10 copper-nickel (CuNi10Fe1Mn1) with iron and manganese additions, standardized under a temper family separate from C70600 and supplied in O61, OS025, H01–H04, HR50, H55, H80 and M20.
Reference datasheet — C70700 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
C70700 tempers and conditions
C70700 is supplied in 9 conditions, soft to hard. O61 is the default FabDigit quotes; the values on this page are for it.
Compare all 9 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Annealed to 0.025 mm grain size | Grain-size-controlled soft temper for deep-drawn parts and tube that must be expanded or bent tightly. | 110 | 305 | 44 | 62 HB | 9.5 % IACS |
O61Default Annealed | Default condition for seawater condenser/heat-exchanger tube and formed fittings needing maximum ductility. | 115 | 310 | 42 | 65 HB | 9.5 % IACS |
As hot rolled | Mill hot-rolled plate for welded seawater vessels, tube sheets and offshore piping spools. | 125 | 305 | 35 | 70 HB | 9.5 % IACS |
Quarter hard | Light temper strip for formed components needing a little extra stiffness and yield. | 240 | 345 | 30 | 100 HB | 9.3 % IACS |
Light drawn tube | Standard light-drawn tube temper giving higher pressure rating while still allowing bending and expansion. | 275 | 345 | 25 | 100 HB | 9.4 % IACS |
Drawn and stress-relieved tube | Drawn then stress-relieved for dimensional stability and reduced residual stress in long condenser tubes. | 275 | 370 | 22 | 105 HB | 9.4 % IACS |
Half hard | General-purpose hard strip for flat parts, washers and clamps where moderate forming is still needed. | 330 | 395 | 15 | 125 HB | 9.3 % IACS |
Hard drawn | Hard-drawn tube or rod for high-pressure lines and machined fittings where ductility is secondary. | 380 | 415 | 12 | 145 HB | 9.3 % IACS |
Full hard | Choose for maximum strength and spring-back in flat or drawn products with no further forming. | 395 | 435 | 10 | 150 HB | 9.3 % IACS |
What is C70700?
C70700 is a 90/10 copper-nickel (CuNi10Fe1Mn1) with iron and manganese additions, standardized under a temper family separate from C70600 and supplied in O61, OS025, H01–H04, HR50, H55, H80 and M20. Annealed properties are 310 MPa tensile, 115 MPa yield and 42 % elongation, with 9.5 % IACS conductivity and a formability score of 90, so it is used interchangeably with C70600 for marine tube, pipe and fittings. Machinability is about 20 % of AISI 1212, making it a forming and welding grade rather than a bar-stock one; use 70/30 Cu-Ni where seawater velocity is higher. C70700 has a density of 8.94 g/cm³ (0.323 lb/in³), heavier than 90% of copper alloy grades. It melts at 1,100°C (2,012 °F). C70700 has a yield strength of 115 MPa (16.7 ksi) and a tensile strength of 310 MPa (45 ksi) — weaker than 80% of copper alloy grades. Elongation at break is 42% and the elastic modulus is 124 GPa (18 Msi).
What is C70700 used for?
- marine tubing
- heat exchanger tubes
- fittings
Advantages
- 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
- Good corrosion resistance — 78/100, better than 94% of copper alloy grades
- Forms and bends easily — 90/100, better than 89% of copper alloy grades
- Ductile — tolerates forming and impact — 42%, better than 86% of copper alloy grades
Limitations
- High embodied carbon — 4.8 kg CO₂/kg, worse than 84% of copper alloy grades
- Poor heat conductor — 40 W/m·K (23.1 BTU/hr·ft·°F), worse than 82% of copper alloy grades
- Low strength — 115 MPa (16.7 ksi), worse than 80% of copper alloy grades
- Low electrical conductivity — 9.5 % IACS, worse than 76% of copper alloy grades
C70700 properties
Typical room-temperature values for C70700-O61; bars are the position among copper alloy grades.
Physical3
C70700 has a density of 8.94 g/cm³ (0.323 lb/in³), heavier than 90% of copper alloy grades. It melts at 1,100°C (2,012 °F).
Mechanical14
C70700 has a yield strength of 115 MPa (16.7 ksi) and a tensile strength of 310 MPa (45 ksi) — weaker than 80% of copper alloy grades. Elongation at break is 42% and the elastic modulus is 124 GPa (18 Msi).
Thermal6
C70700 is rated for continuous service to 350°C (662 °F). It conducts heat at 40 W/m·K (23.1 BTU/hr·ft·°F), worse than 82% of copper alloy grades. Thermal expansion is 17.1 µm/m·K (9.5 µin/in·°F).
Electrical3
C70700 conducts electricity at 9.5 % IACS, worse than 76% of copper alloy grades.
Chemical & Environmental3
Corrosion resistance is very good (78/100), better than 94% of copper alloy grades.
Sustainability4
Producing a kilogram of C70700 takes about 70 MJ of energy and emits 4.8 kg of CO₂ — more than 84% of copper alloy grades. Typical recycled content is 30%.
Manufacturability8
C70700's machinability is poor (30/100, worse than 67% of copper alloy grades); weldability excellent (88/100); formability excellent (90/100).
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. C70700 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with C70700
Is C70700 easy to machine?
Gummy and work-hardening — use sharp positive-rake carbide, high feed/low speed, rigid setups and copious coolant; rating ≈20 % of AISI 1212.
Can C70700 be welded?
Readily GTAW/GMAW welded with 70/30 CuNi (ERCuNi) filler, no preheat, low interpass temperature; keep joints clean and free of sulphur, lead and oil.
Can C70700 be formed, bent or molded?
Excellent cold formability in O61/OS tempers — deep drawing, tube bending and expansion are routine; interanneal at 700–850 °C with rapid cooling.
C70700 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 reported together in most specs | 9 – 11 | 10 |
| Feiron in solid solution gives impingement resistance | 1 – 1.8 | 1.4 |
| Mndeoxidizer / sulphur scavenger | 0.3 – 1 | 0.6 |
| Zn | ≤ 0.5 | |
| Pbkept low for weldability | ≤ 0.03 | |
| C | ≤ 0.05 | |
| S | ≤ 0.02 | |
| P | ≤ 0.02 | |
| Curemainder, ≈88 % including any silver | balance |
What surface finishes work on C70700?
Not anodizable; supplied bright or pickled, takes tin/nickel electroplating and solders easily. In seawater allow the protective oxide film to form on clean surfaces before high-velocity service.
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 C70700 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- Also called
- CuNi10
- Similar grades
- CuNi10Fe1Mn1
How much does C70700 cost?
C70700 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.
C70700 — frequently asked
What is C70700 used for?
C70700 is typically used for marine tubing, heat exchanger tubes and fittings. In short: 90/10 Cu-Ni tube grade; interchangeable with C70600; weld and form, not machine.
What is the yield strength of C70700?
C70700 has a typical yield strength of 115 MPa (16.7 ksi) and a tensile strength of 310 MPa (45 ksi) — weaker than 80% of copper alloy grades. Strength varies by condition: see the 9 listed tempers.
Is C70700 easy to machine?
Not especially — machinability is rated poor (30/100, worse than 67% of copper alloy grades). Gummy and work-hardening — use sharp positive-rake carbide, high feed/low speed, rigid setups and copious coolant; rating ≈20 % of AISI 1212.
Can C70700 be welded?
Yes — weldability is rated excellent (88/100). Readily GTAW/GMAW welded with 70/30 CuNi (ERCuNi) filler, no preheat, low interpass temperature; keep joints clean and free of sulphur, lead and oil.
What surface finishes work on C70700?
Not anodizable; supplied bright or pickled, takes tin/nickel electroplating and solders easily. In seawater allow the protective oxide film to form on clean surfaces before high-velocity service.
Can C70700 be formed, bent or molded?
Excellent cold formability in O61/OS tempers — deep drawing, tube bending and expansion are routine; interanneal at 700–850 °C with rapid cooling.
What is the maximum service temperature of C70700?
C70700 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 C70700-O61 and C70700-H04?
O61 is the default condition — default condition for seawater condenser/heat-exchanger tube and formed fittings needing maximum ductility. H04: choose for maximum strength and spring-back in flat or drawn products with no further forming. Yield strength is 115 MPa in O61 versus 395 MPa in H04.
How much does C70700 cost?
C70700 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
- ASTM B111/B111M — Copper and Copper-Alloy Seamless Condenser Tubes — ASTM International (2021)
- ASTM B171/B171M — Copper-Alloy Plate and Sheet for Pressure Vessels and Condensers — ASTM International (2018)
- ASTM B466/B466M — Seamless Copper-Nickel Pipe and Tube — ASTM International (2020)
- CDA UNS alloy datasheets — C70600/C70700 copper-nickel 10 % — Copper Development Association (2023)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
- Copper-Nickel Alloys: Properties and Seawater Service Guidance — Nickel Institute / CDA UK (2020)
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.