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Copper Alloy C71700-H80

Temper

UNS C71700

H80 = hard drawn

Highest-pressure tubing condition; use where hoop strength governs and no further cold bending is needed.

High cost $$$$

Values for the H80 condition

Other C71700 tempers and conditions

C71700 is listed in 7 conditions; see the grade overview at C71700.

Compare all 7 conditionsHide
Condition · open for datasheetBest forYield MPaTensile MPaElong. %HardnessConductivity
Annealed to 0.025 mm grain size
Grain-size-controlled anneal for sheet/strip that must be deep drawn or spun without orange peel.1503904580 HB4.6 % IACS
O61Default
Annealed
Standard stocked condition for seawater and aerospace tubing where bending, flaring and welding are required.1604004285 HB4.6 % IACS
Light drawn
Choose for straight tube lengths needing better handling stiffness while still allowing moderate bending.27545025118 HB4.5 % IACS
Quarter hard
Mild cold work for flat products that still need forming after cutting.31047022125 HB4.6 % IACS
Half hard
General structural flat/rod condition balancing strength and residual formability.42054014155 HB4.6 % IACS
H80This page
Hard drawn
Highest-pressure tubing condition; use where hoop strength governs and no further cold bending is needed.515585109 HRC4.5 % IACS
Full hard
Maximum as-drawn/rolled strength for springs, fasteners and wear faces; minimal further forming.550620813 HRC4.5 % IACS

What is C71700-H80?

C71700-H80 is C71700 in the H80 temper — highest-pressure tubing condition; use where hoop strength governs and no further cold bending is needed. C71700-H80 has a yield strength of 515 MPa (74.7 ksi) and a tensile strength of 585 MPa (84.8 ksi) — stronger than 91% of copper alloy grades. Elongation at break is 10% and the elastic modulus is 152 GPa (22 Msi). C71700-H80 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). O61 is the default condition FabDigit quotes; H80 is available on request or by drawing note.

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 — 85/100, better than 95% of copper alloy grades
  • High strength — 515 MPa (74.7 ksi), better than 91% of copper alloy grades
  • High service temperature — 300°C (572 °F), better than 85% of copper alloy grades

Limitations

  • Low electrical conductivity — 4.5 % IACS, worse than 98% of copper alloy grades
  • High embodied carbon — 7.5 kg CO₂/kg, worse than 97% of copper alloy grades
  • Poor heat conductor — 29 W/m·K (16.8 BTU/hr·ft·°F), worse than 93% of copper alloy grades
  • Limited ductility — 10%, worse than 76% of copper alloy grades

C71700-H80 properties

Typical room-temperature values for C71700-H80; 22 are specific to this condition. Other listed values are C71700 reference data and may not represent this condition. Bars are the position among copper alloy grades.

Physical3

C71700-H80 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).

Density8.94 g/cm³0.32 lb/in³
Melting Point (Solidus)1,170°C2,138 °F
Liquidus Temperature1,240°C2,264 °F

Mechanical14

C71700-H80 has a yield strength of 515 MPa (74.7 ksi) and a tensile strength of 585 MPa (84.8 ksi) — stronger than 91% of copper alloy grades. Elongation at break is 10% and the elastic modulus is 152 GPa (22 Msi).

Elastic (Young's) Modulus152 GPa22 Msi
Shear Modulus57 GPa8.3 Msi
Bulk Modulus140 GPa20.3 Msi
Poisson's Ratio0.33
Tensile Strength (Ultimate)585 MPa84.8 ksi
Yield Strength (0.2% offset)515 MPa74.7 ksi
Elongation at Break10%
Reduction in Area35%
Shear Strength380 MPa55.1 ksi
Fatigue Strength (Endurance Limit)200 MPa29 ksi
Charpy V-Notch Impact (RT)40 J29.5 ft·lbf
Hardness, Brinell175 HB
Hardness, Rockwell B88 HRB
Hardness, Vickers185 HV

Thermal6

C71700-H80 is rated for continuous service to 300°C (572 °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).

Thermal Conductivity29 W/m·K16.8 BTU/hr·ft·°F
Specific Heat Capacity377 J/kg·K0.09 BTU/lb·°F
Thermal Expansion (CTE, 20–100 °C)16.2 µm/m·K9 µin/in·°F
Latent Heat of Fusion220 J/g94.6 BTU/lb
Max Service Temperature (continuous)300°C572 °F
Min Service Temperature-196°C-321 °F

Electrical3

C71700-H80 conducts electricity at 4.5 % IACS, worse than 98% of copper alloy grades.

Electrical Conductivity4.5 % IACS
Electrical Resistivity3.83×10⁻⁷ Ω·m15.1 µΩ·in
Magnetic Responsenon-magnetic (relative permeability typically <1.03 when Fe is in solution; heavy cold work or Fe segregation can make it weakly magnetic)

Chemical & Environmental3

Corrosion resistance is very good (82/100), better than 98% of copper alloy grades.

Galvanic Potential (seawater, vs SCE)-0.25 V
Corrosion ResistanceVery good82/100
Chemical Resistance SummaryExcellent in flowing seawater and brackish water (erosion-corrosion limit ~4.5 m/s), resists biofouling, dilute non-oxidising acids, alkalis and hydrocarbons; attacked by ammonia/amines, oxidising acids (HNO₃), ferric/cupric chlorides, wet H₂S and sulphide-polluted stagnant seawater.

Sustainability4

Producing a kilogram of C71700-H80 takes about 105 MJ of energy and emits 7.5 kg of CO₂ — more than 97% of copper alloy grades. Typical recycled content is 30%.

Embodied Energy (primary production)105 MJ/kg45,142 BTU/lb
Embodied Carbon (primary production)7.5 kg CO₂/kg
Embodied Water300 L/kg35.9 gal/lb
Typical Recycled Content30%

Manufacturability8

C71700-H80's machinability is poor (30/100, worse than 67% of copper alloy grades); weldability excellent (85/100); formability fair (35/100).

MachinabilityPoor30/100
Machinability Rating (AISI 1212 = 100 %)30%
WeldabilityExcellent85/100
Formability (cold)Fair35/100
CastabilityFair45/100
Brazeability / SolderabilityVery good80/100
PolishabilityVery good75/100
Anodizing Responsen/a — copper alloy; use chemical passivation, tin/nickel plating or clear lacquer instead

Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.

Working with C71700-H80

Is C71700 easy to machine?

Gummy and work-hardening — use sharp positive-rake carbide, low speed (~30–60 m/min), heavy feed, rigid setup and flood coolant to avoid built-up edge.

Can C71700 be welded?

Excellent GTAW/GMAW with CuNi 70/30 (ERCuNi) filler; the Nb addition suppresses weld hot cracking and porosity — keep interpass low, no preheat, argon backing, and avoid sulphur/lead contamination.

Can C71700 be formed, bent or molded?

Very good cold formability in O61 (bend radii ≈1t); high work-hardening rate means interstage anneals at 700–850 °C with rapid cool for severe draws; hot work 900–1050 °C.

What surface finishes work on C71700?

Cannot be anodised; pickle in inhibited sulphuric/chromate-free solutions, then leave bare (self-forming protective oxide in seawater), or electroplate Ni/Sn or lacquer for decorative use — polishes to a bright silvery finish.

C71700 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.

ElementSpec limit (wt %)Nominal
NiNi + Co29 – 3331
Feerosion-corrosion resistance0.4 – 10.7
Mndeoxidiser0.4 – 10.7
Nbcolumbium; stabilises weld metal0.2 – 0.70.45
Zn≤ 1—
Pb≤ 0.05—
C≤ 0.05—
S≤ 0.02—
P≤ 0.02—
Curemainder, ~65–68 %balance—

C71700-H80 — frequently asked

What is C71700-H80 used for?

C71700-H80 is typically used for aircraft hydraulic tubing, fuel lines and seawater piping. In short: weldable 70/30 copper-nickel; aerospace hydraulic tube alloy; highest formability in family.

What is the yield strength of C71700-H80?

C71700-H80 has a typical yield strength of 515 MPa (74.7 ksi) and a tensile strength of 585 MPa (84.8 ksi) — stronger than 91% of copper alloy grades. Strength varies by condition: see the 7 listed tempers.

Is C71700-H80 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, low speed (~30–60 m/min), heavy feed, rigid setup and flood coolant to avoid built-up edge.

Can C71700-H80 be welded?

Yes — weldability is rated excellent (85/100). Excellent GTAW/GMAW with CuNi 70/30 (ERCuNi) filler; the Nb addition suppresses weld hot cracking and porosity — keep interpass low, no preheat, argon backing, and avoid sulphur/lead contamination.

What surface finishes work on C71700-H80?

Cannot be anodised; pickle in inhibited sulphuric/chromate-free solutions, then leave bare (self-forming protective oxide in seawater), or electroplate Ni/Sn or lacquer for decorative use — polishes to a bright silvery finish.

Can C71700-H80 be formed, bent or molded?

Very good cold formability in O61 (bend radii ≈1t); high work-hardening rate means interstage anneals at 700–850 °C with rapid cool for severe draws; hot work 900–1050 °C.

What is the maximum service temperature of C71700-H80?

C71700-H80 is rated for continuous use to about 300°C (572 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.

What is the difference between C71700-O61 and C71700-H04?

O61 is the default condition — standard stocked condition for seawater and aerospace tubing where bending, flaring and welding are required. H04: maximum as-drawn/rolled strength for springs, fasteners and wear faces; minimal further forming. Yield strength is 160 MPa in O61 versus 550 MPa in H04.

Sources

  1. ASTM B466/B466M — Seamless Copper-Nickel Pipe and Tube — ASTM International (2020)
  2. ASTM B122/B122M — Copper-Nickel-Zinc, Copper-Nickel Plate, Sheet, Strip and Rolled Bar — ASTM International (2021)
  3. CDA Standard Designations for Wrought Copper Alloys (UNS C71700) — Copper Development Association (2023)
  4. ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys and Special-Purpose Materials — ASM International (1990)
  5. ASM Handbook Vol. 13B — Corrosion: Materials (Copper-Nickel in Seawater) — ASM International (2005)
  6. Copper-Nickel Alloys — Properties and Fabrication Guide — Nickel Institute / CDA UK (2016)

Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.