UNS C97600 (Alloy 11A) Dairy Metal
C97600 dairy metal is a copper-nickel alloy formulated for casting. Cited properties are appropriate for the as-fabricated (no temper or treatment) condition. C97600 is the UNS number for this material. Additionally, the common industry name is 20% Leaded Nickel Silver. Older literature may refer to this material as ASTM Alloy 11A, but this is now discouraged.
It has the lowest thermal conductivity among cast copper-nickels. In addition, it has a moderately low heat capacity and a moderately low electrical conductivity.
The graph bars on the material properties cards below compare C97600 dairy metal 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
120 GPa 18 x 106 psi
Elongation at Break
11 %
Poisson's Ratio
0.33
Shear Modulus
46 GPa 6.6 x 106 psi
Tensile Strength: Ultimate (UTS)
310 MPa 45 x 103 psi
Tensile Strength: Yield (Proof)
140 MPa 21 x 103 psi
Thermal Properties
Latent Heat of Fusion
210 J/g
Maximum Temperature: Mechanical
210 °C 400 °F
Melting Completion (Liquidus)
1140 °C 2090 °F
Melting Onset (Solidus)
1110 °C 2030 °F
Specific Heat Capacity
380 J/kg-K 0.091 BTU/lb-°F
Thermal Conductivity
22 W/m-K 13 BTU/h-ft-°F
Thermal Expansion
17 µm/m-K
Electrical Properties
Electrical Conductivity: Equal Volume
5.0 % IACS
Electrical Conductivity: Equal Weight (Specific)
5.1 % IACS
Otherwise Unclassified Properties
Base Metal Price
37 % relative
Density
8.8 g/cm3 550 lb/ft3
Embodied Carbon
4.6 kg CO2/kg material
Embodied Energy
69 MJ/kg 30 x 103 BTU/lb
Embodied Water
330 L/kg 39 gal/lb
Common Calculations
Resilience: Ultimate (Unit Rupture Work)
29 MJ/m3
Resilience: Unit (Modulus of Resilience)
85 kJ/m3
Stiffness to Weight: Axial
7.7 points
Stiffness to Weight: Bending
19 points
Strength to Weight: Axial
9.8 points
Strength to Weight: Bending
12 points
Thermal Diffusivity
6.5 mm2/s
Thermal Shock Resistance
11 points
Alloy Composition
Among cast copper alloys, the composition of C97600 dairy metal 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.
| Cu | 63 to 67 | |
| Ni | 19 to 21.5 | |
| Zn | 3.0 to 9.0 | |
| Pb | 3.0 to 5.0 | |
| Sn | 3.5 to 4.0 | |
| Fe | 0 to 1.5 | |
| Sb | 0 to 0.25 | |
| Si | 0 to 0.15 | |
| S | 0 to 0.080 | |
| P | 0 to 0.050 | |
| Al | 0 to 0.0050 | |
| res. | 0 to 0.3 |
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