UNS C85700 Leaded Naval Brass
C85700 brass is a brass formulated for casting. Cited properties are appropriate for the as-fabricated (no temper or treatment) condition. C85700 is the UNS number for this material. Older literature may refer to this material as ASTM Alloy 6C, but this is now discouraged.
It has a moderately high melting temperature among the cast brasses in the database.
The graph bars on the material properties cards below compare C85700 brass to: cast brasses (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
100 GPa 15 x 106 psi
Elongation at Break
17 %
Poisson's Ratio
0.31
Shear Modulus
40 GPa 5.7 x 106 psi
Tensile Strength: Ultimate (UTS)
310 MPa 45 x 103 psi
Tensile Strength: Yield (Proof)
110 MPa 16 x 103 psi
Thermal Properties
Latent Heat of Fusion
170 J/g
Maximum Temperature: Mechanical
120 °C 250 °F
Melting Completion (Liquidus)
940 °C 1730 °F
Melting Onset (Solidus)
910 °C 1680 °F
Specific Heat Capacity
380 J/kg-K 0.091 BTU/lb-°F
Thermal Conductivity
84 W/m-K 49 BTU/h-ft-°F
Thermal Expansion
21 µm/m-K
Electrical Properties
Electrical Conductivity: Equal Volume
22 % IACS
Electrical Conductivity: Equal Weight (Specific)
25 % IACS
Otherwise Unclassified Properties
Base Metal Price
24 % relative
Density
8.0 g/cm3 500 lb/ft3
Embodied Carbon
2.8 kg CO2/kg material
Embodied Energy
47 MJ/kg 20 x 103 BTU/lb
Embodied Water
330 L/kg 39 gal/lb
Common Calculations
Resilience: Ultimate (Unit Rupture Work)
41 MJ/m3
Resilience: Unit (Modulus of Resilience)
59 kJ/m3
Stiffness to Weight: Axial
7.2 points
Stiffness to Weight: Bending
20 points
Strength to Weight: Axial
11 points
Strength to Weight: Bending
13 points
Thermal Diffusivity
27 mm2/s
Thermal Shock Resistance
10 points
Alloy Composition
Among cast copper alloys, the composition of C85700 brass is notable for containing a comparatively high amount of lead (Pb). Lead is used to improve machinability and bearing properties, at the cost of toxicity. It also adds pressure tightness to castings.
| Cu | 58 to 64 | |
| Zn | 32 to 40 | |
| Pb | 0.8 to 1.5 | |
| Sn | 0.5 to 1.5 | |
| Ni | 0 to 1.0 | |
| Al | 0 to 0.8 | |
| Fe | 0 to 0.7 | |
| Si | 0 to 0.050 | |
| res. | 0 to 1.3 |
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
ASTM B505: Standard Specification for Copper Alloy Continuous Castings
ASM Specialty Handbook: Copper and Copper Alloys, J. R. Davis (editor), 2001