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UNS C82000 (Alloy 10C) Cobalt-Beryllium Copper

C82000 copper is a lightly alloyed grade of copper, formulated for casting. C82000 is the UNS number for this material. Older literature may refer to this material as ASTM Alloy 10C, but this is now discouraged.

It has the highest base cost among cast coppers. In addition, it has a moderately low electrical conductivity and a fairly low melting temperature.

The properties of C82000 copper 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 C82000 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 17 x 106 psi

Elongation at Break

8.0 to 20 %

Poisson's Ratio


Rockwell B Hardness

55 to 95

Shear Modulus

45 GPa 6.5 x 106 psi

Tensile Strength: Ultimate (UTS)

350 to 690 MPa 50 to 100 x 103 psi

Tensile Strength: Yield (Proof)

140 to 520 MPa 20 to 75 x 103 psi

Thermal Properties

Latent Heat of Fusion

220 J/g

Maximum Temperature: Mechanical

220 °C 440 °F

Melting Completion (Liquidus)

1090 °C 1990 °F

Melting Onset (Solidus)

970 °C 1780 °F

Specific Heat Capacity

390 J/kg-K 0.092 BTU/lb-°F

Thermal Conductivity

260 W/m-K 150 BTU/h-ft-°F

Thermal Expansion

17 µm/m-K

Electrical Properties

Electrical Conductivity: Equal Volume

45 % IACS

Electrical Conductivity: Equal Weight (Specific)

46 % IACS

Otherwise Unclassified Properties

Base Metal Price

60 % relative


8.9 g/cm3 550 lb/ft3

Embodied Carbon

5.0 kg CO2/kg material

Embodied Energy

77 MJ/kg 33 x 103 BTU/lb

Embodied Water

320 L/kg 38 gal/lb

Common Calculations

Resilience: Ultimate (Unit Rupture Work)

51 to 55 MJ/m3

Resilience: Unit (Modulus of Resilience)

80 to 1120 kJ/m3

Stiffness to Weight: Axial

7.5 points

Stiffness to Weight: Bending

18 points

Strength to Weight: Axial

11 to 22 points

Strength to Weight: Bending

12 to 20 points

Thermal Diffusivity

76 mm2/s

Thermal Shock Resistance

12 to 24 points

Alloy Composition

Among cast copper alloys, the composition of C82000 copper is notable for including cobalt (Co) and beryllium (Be). Cobalt is used to improve strength. Beryllium is used to permit precipitation hardening (which increases strength) without much effect on electrical conductivity, but at the cost of substantial toxicity.

Copper (Cu)Cu 95.2 to 97.4
Cobalt (Co)Co 2.2 to 2.7
Beryllium (Be)Be 0.45 to 0.8
Nickel (Ni)Ni 0 to 0.2
Silicon (Si)Si 0 to 0.15
Chromium (Cr)Cr 0 to 0.1
Iron (Fe)Fe 0 to 0.1
Aluminum (Al)Al 0 to 0.1
Tin (Sn)Sn 0 to 0.1
Zinc (Zn)Zn 0 to 0.1
Lead (Pb)Pb 0 to 0.020
Residualsres. 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

CRC Materials Science and Engineering Handbook, 4th ed., James F. Shackelford et al. (editors), 2015