UNS C76400 Nickel Silver
C76400 nickel silver is a copper-nickel alloy formulated for primary forming into wrought products. C76400 is the UNS number for this material. Additionally, the EN chemical designation is CuNi18Zn20. It can have a moderately high tensile strength among the wrought copper-nickels in the database.
The properties of C76400 nickel silver 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 C76400 nickel silver 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
Poisson's Ratio
0.32
Shear Modulus
46 GPa 6.7 x 106 psi
Tensile Strength: Ultimate (UTS)
590 to 610 MPa 85 to 88 x 103 psi
Thermal Properties
Latent Heat of Fusion
200 J/g
Maximum Temperature: Mechanical
190 °C 370 °F
Melting Completion (Liquidus)
990 °C 1820 °F
Melting Onset (Solidus)
950 °C 1730 °F
Specific Heat Capacity
400 J/kg-K 0.095 BTU/lb-°F
Thermal Conductivity
31 W/m-K 18 BTU/h-ft-°F
Thermal Expansion
18 µm/m-K
Electrical Properties
Electrical Conductivity: Equal Volume
5.7 % IACS
Electrical Conductivity: Equal Weight (Specific)
6.1 % IACS
Otherwise Unclassified Properties
Base Metal Price
32 % relative
Density
8.4 g/cm3 520 lb/ft3
Embodied Carbon
4.1 kg CO2/kg material
Embodied Energy
63 MJ/kg 27 x 103 BTU/lb
Embodied Water
300 L/kg 36 gal/lb
Common Calculations
Stiffness to Weight: Axial
8.1 points
Stiffness to Weight: Bending
20 points
Strength to Weight: Axial
19 to 20 points
Strength to Weight: Bending
18 to 19 points
Thermal Diffusivity
9.3 mm2/s
Thermal Shock Resistance
19 to 20 points
Alloy Composition
Among wrought copper alloys, the composition of C76400 nickel silver is notable for including manganese (Mn) and nickel (Ni). Manganese is used to improve strength without a proportional reduction in ductility. Nickel is used to improve strength (particularly at elevated temperatures) and corrosion resistance.
| Cu | 58.5 to 61.5 | |
| Zn | 17.7 to 25 | |
| Ni | 16.5 to 19.5 | |
| Mn | 0 to 0.5 | |
| Fe | 0 to 0.25 | |
| Pb | 0 to 0.050 | |
| res. | 0 to 0.5 |
All values are % weight. Ranges represent what is permitted under applicable standards.
Followup Questions
Similar Alloys
Further Reading
ASTM B151: Standard Specification for Copper-Nickel-Zinc Alloy (Nickel Silver) and Copper-Nickel Rod and Bar
ASM Specialty Handbook: Copper and Copper Alloys, J. R. Davis (editor), 2001
CRC Materials Science and Engineering Handbook, 4th ed., James F. Shackelford et al. (editors), 2015