UNS C67000 (CW704R) Manganese Bronze
C67000 bronze is a bronze formulated for primary forming into wrought products. CW704R is the EN numeric designation for this material. C67000 is the UNS number. Additionally, the EN chemical designation is CuZn23Al6Mn4Fe3Pb.
It has a moderately low base cost among wrought bronzes. In addition, it has a fairly low melting temperature and can have a moderately high tensile strength.
The properties of C67000 bronze include three 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 C67000 bronze to: wrought bronzes (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
110 GPa 16 x 106 psi
Elongation at Break
5.6 to 11 %
Poisson's Ratio
0.31
Shear Modulus
42 GPa 6.1 x 106 psi
Shear Strength
390 to 510 MPa 57 to 75 x 103 psi
Tensile Strength: Ultimate (UTS)
660 to 880 MPa 95 to 130 x 103 psi
Tensile Strength: Yield (Proof)
350 to 540 MPa 51 to 78 x 103 psi
Thermal Properties
Latent Heat of Fusion
190 J/g
Maximum Temperature: Mechanical
160 °C 310 °F
Melting Completion (Liquidus)
900 °C 1650 °F
Melting Onset (Solidus)
850 °C 1570 °F
Specific Heat Capacity
410 J/kg-K 0.1 BTU/lb-°F
Thermal Conductivity
99 W/m-K 57 BTU/h-ft-°F
Thermal Expansion
20 µm/m-K
Electrical Properties
Electrical Conductivity: Equal Volume
22 % IACS
Electrical Conductivity: Equal Weight (Specific)
25 % IACS
Otherwise Unclassified Properties
Base Metal Price
23 % relative
Density
7.9 g/cm3 500 lb/ft3
Embodied Carbon
2.9 kg CO2/kg material
Embodied Energy
49 MJ/kg 21 x 103 BTU/lb
Embodied Water
350 L/kg 42 gal/lb
Common Calculations
Resilience: Ultimate (Unit Rupture Work)
43 to 62 MJ/m3
Resilience: Unit (Modulus of Resilience)
560 to 1290 kJ/m3
Stiffness to Weight: Axial
7.8 points
Stiffness to Weight: Bending
20 points
Strength to Weight: Axial
23 to 31 points
Strength to Weight: Bending
21 to 26 points
Thermal Diffusivity
30 mm2/s
Thermal Shock Resistance
21 to 29 points
Alloy Composition
Among wrought copper alloys, the composition of C67000 bronze is notable for including aluminum (Al) and containing a comparatively high amount of iron (Fe). Aluminum is used to add strength and oxidation resistance. Iron is used to increase strength inexpensively.
| Cu | 63 to 68 | |
| Zn | 21.8 to 32.5 | |
| Al | 3.0 to 6.0 | |
| Mn | 2.5 to 5.0 | |
| Fe | 2.0 to 4.0 | |
| Sn | 0 to 0.5 | |
| Pb | 0 to 0.2 | |
| res. | 0 to 0.5 |
All values are % weight. Ranges represent what is permitted under applicable standards.
Followup Questions
Similar Alloys
Further Reading
ASTM B138: Standard Specification for Manganese Bronze Rod, Bar, and Shapes
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