UNS C72900 Tin-Bearing Copper-Nickel
C72900 copper-nickel is a copper-nickel alloy formulated for primary forming into wrought products. It can have a moderately high tensile strength among wrought copper-nickels. In addition, it has a moderately high base cost and a moderately high embodied energy.
The properties of C72900 copper-nickel include five 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 C72900 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 18 x 106 psi
Elongation at Break
6.0 to 20 %
Poisson's Ratio
0.34
Shear Modulus
45 GPa 6.6 x 106 psi
Shear Strength
540 to 630 MPa 79 to 92 x 103 psi
Tensile Strength: Ultimate (UTS)
870 to 1080 MPa 130 to 160 x 103 psi
Tensile Strength: Yield (Proof)
700 to 920 MPa 100 to 130 x 103 psi
Thermal Properties
Latent Heat of Fusion
210 J/g
Maximum Temperature: Mechanical
210 °C 400 °F
Melting Completion (Liquidus)
1120 °C 2040 °F
Melting Onset (Solidus)
950 °C 1740 °F
Specific Heat Capacity
380 J/kg-K 0.091 BTU/lb-°F
Thermal Conductivity
29 W/m-K 17 BTU/h-ft-°F
Thermal Expansion
17 µm/m-K
Electrical Properties
Electrical Conductivity: Equal Volume
7.8 % IACS
Electrical Conductivity: Equal Weight (Specific)
8.0 % IACS
Otherwise Unclassified Properties
Base Metal Price
39 % relative
Density
8.8 g/cm3 550 lb/ft3
Embodied Carbon
4.6 kg CO2/kg material
Embodied Energy
72 MJ/kg 31 x 103 BTU/lb
Embodied Water
360 L/kg 43 gal/lb
Common Calculations
Resilience: Ultimate (Unit Rupture Work)
49 to 210 MJ/m3
Resilience: Unit (Modulus of Resilience)
2030 to 3490 kJ/m3
Stiffness to Weight: Axial
7.6 points
Stiffness to Weight: Bending
19 points
Strength to Weight: Axial
27 to 34 points
Strength to Weight: Bending
23 to 27 points
Thermal Diffusivity
8.6 mm2/s
Thermal Shock Resistance
31 to 38 points
Alloy Composition
Among wrought copper alloys, the composition of C72900 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.
| Cu | 74.1 to 78 | |
| Ni | 14.5 to 15.5 | |
| Sn | 7.5 to 8.5 | |
| Fe | 0 to 0.5 | |
| Zn | 0 to 0.5 | |
| Mn | 0 to 0.3 | |
| Mg | 0 to 0.15 | |
| Nb | 0 to 0.1 | |
| Pb | 0 to 0.020 | |
| res. | 0 to 0.3 |
All values are % weight. Ranges represent what is permitted under applicable standards.