UNS C82700 Beryllium-Nickel Copper
C82700 copper is a lightly alloyed grade of copper, formulated for casting. Cited properties are appropriate for the heat treated (HT) condition. It has a very low melting temperature among cast coppers. In addition, it has the highest tensile strength and a fairly low thermal conductivity.
The graph bars on the material properties cards below compare C82700 copper to: cast coppers (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
1.8 %
Poisson's Ratio
0.33
Rockwell C Hardness
39
Shear Modulus
46 GPa 6.7 x 106 psi
Tensile Strength: Ultimate (UTS)
1200 MPa 170 x 103 psi
Tensile Strength: Yield (Proof)
1020 MPa 150 x 103 psi
Thermal Properties
Latent Heat of Fusion
240 J/g
Maximum Temperature: Mechanical
300 °C 570 °F
Melting Completion (Liquidus)
950 °C 1750 °F
Melting Onset (Solidus)
860 °C 1570 °F
Specific Heat Capacity
380 J/kg-K 0.092 BTU/lb-°F
Thermal Conductivity
130 W/m-K 75 BTU/h-ft-°F
Thermal Expansion
17 µm/m-K
Electrical Properties
Electrical Conductivity: Equal Volume
20 % IACS
Electrical Conductivity: Equal Weight (Specific)
21 % IACS
Otherwise Unclassified Properties
Density
8.7 g/cm3 550 lb/ft3
Embodied Carbon
12 kg CO2/kg material
Embodied Energy
180 MJ/kg 78 x 103 BTU/lb
Embodied Water
310 L/kg 37 gal/lb
Common Calculations
Resilience: Ultimate (Unit Rupture Work)
21 MJ/m3
Resilience: Unit (Modulus of Resilience)
4260 kJ/m3
Stiffness to Weight: Axial
7.8 points
Stiffness to Weight: Bending
19 points
Strength to Weight: Axial
38 points
Strength to Weight: Bending
29 points
Thermal Diffusivity
39 mm2/s
Thermal Shock Resistance
41 points
Alloy Composition
Among cast copper alloys, the composition of C82700 copper is notable for including beryllium (Be) and chromium (Cr). Beryllium is used to permit precipitation hardening (which increases strength) without much effect on electrical conductivity, but at the cost of substantial toxicity. Chromium additions permits certain types of heat treatment to improve mechanical strength.
| Cu | 94.6 to 96.7 | |
| Be | 2.4 to 2.6 | |
| Ni | 1.0 to 1.5 | |
| Fe | 0 to 0.25 | |
| Si | 0 to 0.15 | |
| Al | 0 to 0.15 | |
| Sn | 0 to 0.1 | |
| Zn | 0 to 0.1 | |
| Cr | 0 to 0.090 | |
| Pb | 0 to 0.020 | |
| res. | 0 to 0.5 |
All values are % weight. Ranges represent what is permitted under applicable standards.
Followup Questions
Similar Alloys
Further Reading
ASM Specialty Handbook: Copper and Copper Alloys, J. R. Davis (editor), 2001