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UNS C72700 Tin-Bearing Copper-Nickel

C72700 copper-nickel is a copper-nickel alloy formulated for primary forming into wrought products.

The properties of C72700 copper-nickel include four common variations. This page shows summary ranges across all of them. For more specific values, follow the links immediately below. The graph bars on the material properties cards further below compare C72700 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

120 GPa 17 x 106 psi

Elongation at Break

4.0 to 36 %

Poisson's Ratio


Shear Modulus

44 GPa 6.4 x 106 psi

Shear Strength

310 to 620 MPa 44 to 89 x 103 psi

Tensile Strength: Ultimate (UTS)

460 to 1070 MPa 66 to 150 x 103 psi

Tensile Strength: Yield (Proof)

580 to 1060 MPa 84 to 150 x 103 psi

Thermal Properties

Latent Heat of Fusion

210 J/g

Maximum Temperature: Mechanical

200 °C 390 °F

Melting Completion (Liquidus)

1100 °C 2010 °F

Melting Onset (Solidus)

930 °C 1700 °F

Specific Heat Capacity

380 J/kg-K 0.091 BTU/lb-°F

Thermal Conductivity

54 W/m-K 31 BTU/h-ft-°F

Thermal Expansion

17 µm/m-K

Electrical Properties

Electrical Conductivity: Equal Volume

11 % IACS

Electrical Conductivity: Equal Weight (Specific)

11 % IACS

Otherwise Unclassified Properties

Base Metal Price

36 % relative


8.8 g/cm3 550 lb/ft3

Embodied Carbon

4.0 kg CO2/kg material

Embodied Energy

62 MJ/kg 27 x 103 BTU/lb

Embodied Water

350 L/kg 42 gal/lb

Common Calculations

Resilience: Ultimate (Unit Rupture Work)

20 to 380 MJ/m3

Resilience: Unit (Modulus of Resilience)

1420 to 4770 kJ/m3

Stiffness to Weight: Axial

7.4 points

Stiffness to Weight: Bending

19 points

Strength to Weight: Axial

14 to 34 points

Strength to Weight: Bending

15 to 26 points

Thermal Diffusivity

16 mm2/s

Thermal Shock Resistance

16 to 38 points

Alloy Composition

Among wrought copper alloys, the composition of C72700 copper-nickel is notable for including magnesium (Mg). Magnesium is used to improve strain hardenability. This increases strength but reduces the ability to form the alloy into complex shapes.

Copper (Cu)Cu 82.1 to 86
Nickel (Ni)Ni 8.5 to 9.5
Tin (Sn)Sn 5.5 to 6.5
Iron (Fe)Fe 0 to 0.5
Zinc (Zn)Zn 0 to 0.5
Manganese (Mn)Mn 0.050 to 0.3
Magnesium (Mg)Mg 0 to 0.15
Niobium (Nb)Nb 0 to 0.1
Lead (Pb)Pb 0 to 0.020
Residualsres. 0 to 0.3

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

Followup Questions

Similar Alloys

Further Reading

CRC Materials Science and Engineering Handbook, 4th ed., James F. Shackelford et al. (editors), 2015