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UNS C97800 Leaded Nickel Silver

C97800 nickel silver is a copper-nickel alloy formulated for casting. Cited properties are appropriate for the as-fabricated (no temper or treatment) condition. C97800 is the UNS number for this material. Additionally, the common industry name is 25% Leaded Nickel Silver. Older literature may refer to this material as ASTM Alloy 11B, but this is now discouraged.

It has a fairly low electrical conductivity among cast copper-nickels. In addition, it has a moderately low thermal conductivity and a fairly high melting temperature.

The graph bars on the material properties cards below compare C97800 nickel silver to: cast 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 19 x 106 psi

Elongation at Break

10 %

Poisson's Ratio


Shear Modulus

48 GPa 7.0 x 106 psi

Tensile Strength: Ultimate (UTS)

370 MPa 54 x 103 psi

Tensile Strength: Yield (Proof)

170 MPa 25 x 103 psi

Thermal Properties

Latent Heat of Fusion

220 J/g

Maximum Temperature: Mechanical

230 °C 440 °F

Melting Completion (Liquidus)

1180 °C 2160 °F

Melting Onset (Solidus)

1140 °C 2080 °F

Specific Heat Capacity

390 J/kg-K 0.093 BTU/lb-°F

Thermal Conductivity

25 W/m-K 14 BTU/h-ft-°F

Thermal Expansion

16 µm/m-K

Electrical Properties

Electrical Conductivity: Equal Volume

4.0 % IACS

Electrical Conductivity: Equal Weight (Specific)

4.1 % IACS

Otherwise Unclassified Properties

Base Metal Price

40 % relative


8.8 g/cm3 550 lb/ft3

Embodied Carbon

5.1 kg CO2/kg material

Embodied Energy

76 MJ/kg 33 x 103 BTU/lb

Embodied Water

330 L/kg 39 gal/lb

Common Calculations

Resilience: Ultimate (Unit Rupture Work)

31 MJ/m3

Resilience: Unit (Modulus of Resilience)

120 kJ/m3

Stiffness to Weight: Axial

8.1 points

Stiffness to Weight: Bending

19 points

Strength to Weight: Axial

12 points

Strength to Weight: Bending

13 points

Thermal Diffusivity

7.3 mm2/s

Thermal Shock Resistance

13 points

Alloy Composition

Among cast copper alloys, the composition of C97800 nickel silver is notable for containing comparatively high amounts of nickel (Ni) and lead (Pb). Nickel is used to improve strength (particularly at elevated temperatures) and corrosion resistance. It also creates the need for additional care during casting. Lead is used to improve machinability and bearing properties, at the cost of toxicity. It also adds pressure tightness to castings.

Copper (Cu)Cu 64 to 67
Nickel (Ni)Ni 24 to 27
Tin (Sn)Sn 4.0 to 5.5
Zinc (Zn)Zn 1.0 to 4.0
Lead (Pb)Pb 1.0 to 2.5
Iron (Fe)Fe 0 to 1.5
Antimony (Sb)Sb 0 to 0.2
Silicon (Si)Si 0 to 0.15
Sulfur (S)S 0 to 0.080
Phosphorus (P)P 0 to 0.050
Aluminum (Al)Al 0 to 0.0050
Residualsres. 0 to 0.4

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

Followup Questions

Similar Alloys

Further Reading

ASTM B271: Standard Specification for Copper-Base Alloy Centrifugal Castings

ASTM B505: Standard Specification for Copper Alloy Continuous Castings

Properties and Selection: Nonferrous Alloys and Special-Purpose Materials, ASM Handbook vol. 2, ASM International, 1993