UNS C73500 Nickel Silver
C73500 nickel silver is a copper-nickel alloy formulated for primary forming into wrought products. C73500 is the UNS number for this material. Additionally, the common industry name is 72-18-10. Older literature may refer to this material as ASTM Copper-Nickel Type 1, but this is now discouraged.
The properties of C73500 nickel silver 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 C73500 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
130 GPa 18 x 106 psi
Poisson's Ratio
0.33
Rockwell B Hardness
73 to 88
Rockwell Superficial 30T Hardness
65 to 75
Shear Modulus
47 GPa 6.9 x 106 psi
Tensile Strength: Ultimate (UTS)
380 to 580 MPa 55 to 84 x 103 psi
Thermal Properties
Latent Heat of Fusion
210 J/g
Maximum Temperature: Mechanical
220 °C 420 °F
Melting Completion (Liquidus)
1140 °C 2080 °F
Melting Onset (Solidus)
1090 °C 2000 °F
Specific Heat Capacity
400 J/kg-K 0.095 BTU/lb-°F
Thermal Conductivity
36 W/m-K 21 BTU/h-ft-°F
Thermal Expansion
17 µm/m-K
Electrical Properties
Electrical Conductivity: Equal Volume
6.5 % IACS
Electrical Conductivity: Equal Weight (Specific)
6.7 % IACS
Otherwise Unclassified Properties
Base Metal Price
35 % relative
Density
8.7 g/cm3 540 lb/ft3
Embodied Carbon
4.0 kg CO2/kg material
Embodied Energy
61 MJ/kg 26 x 103 BTU/lb
Embodied Water
300 L/kg 36 gal/lb
Common Calculations
Stiffness to Weight: Axial
8.0 points
Stiffness to Weight: Bending
19 points
Strength to Weight: Axial
12 to 19 points
Strength to Weight: Bending
13 to 18 points
Thermal Diffusivity
10 mm2/s
Thermal Shock Resistance
13 to 19 points
Alloy Composition
Among wrought copper alloys, the composition of C73500 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 | 70.5 to 73.5 | |
| Ni | 16.5 to 19.5 | |
| Zn | 5.7 to 13 | |
| Mn | 0 to 0.5 | |
| Fe | 0 to 0.25 | |
| Pb | 0 to 0.1 | |
| res. | 0 to 0.5 |
All values are % weight. Ranges represent what is permitted under applicable standards.
Followup Questions
Similar Alloys
Further Reading
ASTM B122: Standard Specification for Copper-Nickel-Tin Alloy, Copper-Nickel-Zinc Alloy (Nickel Silver), and Copper-Nickel Alloy Plate, Sheet, Strip, and Rolled Bar
ASM Specialty Handbook: Copper and Copper Alloys, J. R. Davis (editor), 2001