UNS C86700 Leaded Manganese Bronze
C86700 bronze is a bronze formulated for casting. Cited properties are appropriate for the as-fabricated (no temper or treatment) condition. It has a very low base cost among cast bronzes. In addition, it has a fairly high thermal conductivity and a very high electrical conductivity.
The graph bars on the material properties cards below compare C86700 bronze to: cast 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 15 x 106 psi
Elongation at Break
17 %
Poisson's Ratio
0.31
Shear Modulus
41 GPa 5.9 x 106 psi
Tensile Strength: Ultimate (UTS)
630 MPa 91 x 103 psi
Tensile Strength: Yield (Proof)
250 MPa 36 x 103 psi
Thermal Properties
Latent Heat of Fusion
180 J/g
Maximum Temperature: Mechanical
130 °C 270 °F
Melting Completion (Liquidus)
880 °C 1620 °F
Melting Onset (Solidus)
860 °C 1580 °F
Specific Heat Capacity
400 J/kg-K 0.095 BTU/lb-°F
Thermal Conductivity
89 W/m-K 52 BTU/h-ft-°F
Thermal Expansion
20 µm/m-K
Electrical Properties
Electrical Conductivity: Equal Volume
17 % IACS
Electrical Conductivity: Equal Weight (Specific)
19 % IACS
Otherwise Unclassified Properties
Base Metal Price
23 % relative
Density
7.9 g/cm3 490 lb/ft3
Embodied Carbon
2.9 kg CO2/kg material
Embodied Energy
49 MJ/kg 21 x 103 BTU/lb
Embodied Water
340 L/kg 40 gal/lb
Common Calculations
Resilience: Ultimate (Unit Rupture Work)
86 MJ/m3
Resilience: Unit (Modulus of Resilience)
290 kJ/m3
Stiffness to Weight: Axial
7.5 points
Stiffness to Weight: Bending
20 points
Strength to Weight: Axial
22 points
Strength to Weight: Bending
21 points
Thermal Diffusivity
28 mm2/s
Thermal Shock Resistance
21 points
Alloy Composition
Among cast copper alloys, the composition of C86700 bronze is notable for containing comparatively high amounts of iron (Fe) and aluminum (Al). Iron is used to increase strength inexpensively. Aluminum is used to add strength and oxidation resistance, at the cost of requiring additional care during casting.
| Cu | 55 to 60 | |
| Zn | 30 to 38 | |
| Mn | 1.0 to 3.5 | |
| Fe | 1.0 to 3.0 | |
| Al | 1.0 to 3.0 | |
| Pb | 0.5 to 1.5 | |
| Sn | 0 to 1.5 | |
| Ni | 0 to 1.0 | |
| res. | 0 to 1.0 |
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
Copper: Its Trade, Manufacture, Use, and Environmental Status, Gunter Joseph, 2001
ASM Specialty Handbook: Copper and Copper Alloys, J. R. Davis (editor), 2001