UNS C72800 Tin-Bearing Copper-Nickel
C72800 copper-nickel is a copper-nickel alloy formulated for primary forming into wrought products. It can have the highest tensile strength and has a moderately low melting temperature among wrought copper-nickels.
The properties of C72800 copper-nickel include seven 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 C72800 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
3.9 to 23 %
Poisson's Ratio
0.34
Rockwell C Hardness
21 to 40
Shear Modulus
44 GPa 6.4 x 106 psi
Shear Strength
330 to 740 MPa 48 to 110 x 103 psi
Tensile Strength: Ultimate (UTS)
520 to 1270 MPa 76 to 180 x 103 psi
Tensile Strength: Yield (Proof)
250 to 1210 MPa 36 to 180 x 103 psi
Thermal Properties
Latent Heat of Fusion
210 J/g
Maximum Temperature: Mechanical
200 °C 390 °F
Melting Completion (Liquidus)
1080 °C 1980 °F
Melting Onset (Solidus)
920 °C 1680 °F
Specific Heat Capacity
380 J/kg-K 0.091 BTU/lb-°F
Thermal Conductivity
55 W/m-K 32 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
38 % relative
Density
8.8 g/cm3 550 lb/ft3
Embodied Carbon
4.4 kg CO2/kg material
Embodied Energy
68 MJ/kg 29 x 103 BTU/lb
Embodied Water
360 L/kg 44 gal/lb
Common Calculations
Resilience: Ultimate (Unit Rupture Work)
37 to 99 MJ/m3
Resilience: Unit (Modulus of Resilience)
260 to 5650 kJ/m3
Stiffness to Weight: Axial
7.4 points
Stiffness to Weight: Bending
19 points
Strength to Weight: Axial
17 to 40 points
Strength to Weight: Bending
16 to 30 points
Thermal Diffusivity
17 mm2/s
Thermal Shock Resistance
19 to 45 points
Alloy Composition
Among wrought copper alloys, the composition of C72800 copper-nickel is notable for including sulfur (S) and bismuth (Bi). Sulfur is used to improve machinability at the cost of a decrease in electrical conductivity. Bismuth improves machinability. It is used a non-toxic but more expensive replacement for lead.
| Cu | 78.3 to 82.8 | |
| Ni | 9.5 to 10.5 | |
| Sn | 7.5 to 8.5 | |
| Zn | 0 to 1.0 | |
| Fe | 0 to 0.5 | |
| Nb | 0.1 to 0.3 | |
| Mn | 0.050 to 0.3 | |
| Mg | 0.0050 to 0.15 | |
| Al | 0 to 0.1 | |
| Si | 0 to 0.050 | |
| Sb | 0 to 0.020 | |
| Ti | 0 to 0.010 | |
| Pb | 0 to 0.0050 | |
| P | 0 to 0.0050 | |
| S | 0 to 0.0025 | |
| Bi | 0 to 0.0010 | |
| B | 0 to 0.0010 | |
| res. | 0 to 0.3 |
All values are % weight. Ranges represent what is permitted under applicable standards.