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UNS C71640 Copper-Nickel

C71640 copper-nickel is a copper-nickel alloy formulated for primary forming into wrought products. It has a moderately high base cost and a moderately high embodied energy among wrought copper-nickels.

The properties of C71640 copper-nickel include two common variations. This page shows summary ranges across both of them. For more specific values, follow the links immediately below. The graph bars on the material properties cards further below compare C71640 copper-nickel to: wrought copper-nickels (top), all copper alloys (middle), and the entire database (bottom). A full bar means this is the highest value in the relevant set. A half-full bar means it's 50% of the highest, and so on.

Mechanical Properties

Elastic (Young's, Tensile) Modulus

140 GPa 20 x 106 psi

Poisson's Ratio


Shear Modulus

52 GPa 7.6 x 106 psi

Tensile Strength: Ultimate (UTS)

490 to 630 MPa 71 to 91 x 103 psi

Tensile Strength: Yield (Proof)

190 to 460 MPa 28 to 66 x 103 psi

Thermal Properties

Latent Heat of Fusion

240 J/g

Maximum Temperature: Mechanical

260 °C 500 °F

Melting Completion (Liquidus)

1180 °C 2160 °F

Melting Onset (Solidus)

1120 °C 2050 °F

Specific Heat Capacity

410 J/kg-K 0.1 BTU/lb-°F

Thermal Conductivity

29 W/m-K 17 BTU/h-ft-°F

Thermal Expansion

15 µm/m-K

Electrical Properties

Electrical Conductivity: Equal Volume

7.0 % IACS

Electrical Conductivity: Equal Weight (Specific)

7.1 % IACS

Otherwise Unclassified Properties

Base Metal Price

40 % relative


8.9 g/cm3 550 lb/ft3

Embodied Carbon

5.0 kg CO2/kg material

Embodied Energy

73 MJ/kg 31 x 103 BTU/lb

Embodied Water

280 L/kg 33 gal/lb

Common Calculations

Resilience: Unit (Modulus of Resilience)

130 to 750 kJ/m3

Stiffness to Weight: Axial

8.7 points

Stiffness to Weight: Bending

20 points

Strength to Weight: Axial

15 to 20 points

Strength to Weight: Bending

16 to 18 points

Thermal Diffusivity

8.2 mm2/s

Thermal Shock Resistance

16 to 21 points

Alloy Composition

Among wrought copper alloys, the composition of C71640 copper-nickel is notable for containing a comparatively high amount of iron (Fe) and including manganese (Mn). Iron is used to increase strength inexpensively. Manganese is used to improve strength without a proportional reduction in ductility.

Copper (Cu)Cu 61.7 to 67.8
Nickel (Ni)Ni 29 to 32
Manganese (Mn)Mn 1.5 to 2.5
Iron (Fe)Fe 1.7 to 2.3
Zinc (Zn)Zn 0 to 1.0
Lead (Pb)Pb 0 to 0.050
Residualsres. 0 to 0.5

All values are % weight. Ranges represent what is permitted under applicable standards.

Followup Questions

Similar Alloys

Further Reading

ASTM B111: Standard Specification for Copper and Copper-Alloy Seamless Condenser Tubes and Ferrule Stock

ASM Specialty Handbook: Copper and Copper Alloys, J. R. Davis (editor), 2001