UNS C12900 Fire-Refined Silver-Bearing Tough Pitch Copper
C12900 copper is a lightly alloyed grade of copper, formulated for primary forming into wrought products.
The properties of C12900 copper include nine 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 C12900 copper to: wrought 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
2.8 to 50 %
Poisson's Ratio
0.34
Rockwell F Hardness
40 to 95
Shear Modulus
43 GPa 6.3 x 106 psi
Shear Strength
150 to 210 MPa 22 to 31 x 103 psi
Tensile Strength: Ultimate (UTS)
220 to 420 MPa 32 to 61 x 103 psi
Tensile Strength: Yield (Proof)
75 to 380 MPa 11 to 56 x 103 psi
Thermal Properties
Latent Heat of Fusion
210 J/g
Maximum Temperature: Mechanical
200 °C 390 °F
Melting Completion (Liquidus)
1080 °C 1980 °F
Melting Onset (Solidus)
1030 °C 1880 °F
Specific Heat Capacity
390 J/kg-K 0.092 BTU/lb-°F
Thermal Conductivity
380 W/m-K 220 BTU/h-ft-°F
Thermal Expansion
17 µm/m-K
Electrical Properties
Electrical Conductivity: Equal Volume
98 % IACS
Electrical Conductivity: Equal Weight (Specific)
98 % IACS
Otherwise Unclassified Properties
Base Metal Price
32 % relative
Density
9.0 g/cm3 560 lb/ft3
Embodied Carbon
2.6 kg CO2/kg material
Embodied Energy
41 MJ/kg 18 x 103 BTU/lb
Embodied Water
330 L/kg 39 gal/lb
Common Calculations
Resilience: Ultimate (Unit Rupture Work)
11 to 88 MJ/m3
Resilience: Unit (Modulus of Resilience)
24 to 640 kJ/m3
Stiffness to Weight: Axial
7.2 points
Stiffness to Weight: Bending
18 points
Strength to Weight: Axial
6.8 to 13 points
Strength to Weight: Bending
9.1 to 14 points
Thermal Diffusivity
110 mm2/s
Thermal Shock Resistance
7.8 to 15 points
Alloy Composition
Among wrought copper alloys, the composition of C12900 copper is notable for including bismuth (Bi) and tellurium (Te). Bismuth improves machinability. It is used a non-toxic but more expensive replacement for lead. Tellurium is used to improve machinability.
| Cu | 99.88 to 100 | |
| Ag | 0 to 0.054 | |
| Ni | 0 to 0.050 | |
| Te | 0 to 0.025 | |
| As | 0 to 0.012 | |
| Pb | 0 to 0.0040 | |
| Bi | 0 to 0.0030 | |
| Sb | 0 to 0.0030 |
All values are % weight. Ranges represent what is permitted under applicable standards.
Followup Questions
Similar Alloys
Further Reading
CRC Materials Science and Engineering Handbook, 4th ed., James F. Shackelford et al. (editors), 2015