UNS C85400 Leaded Yellow Brass
C85400 brass is a brass formulated for casting. Cited properties are appropriate for the as-fabricated (no temper or treatment) condition. C85400 is the UNS number for this material. Additionally, the common industry name is No.1 Yellow Brass. Older literature may refer to this material as ASTM Alloy 6B, but this is now discouraged.
It has a fairly low tensile strength and a fairly high melting temperature among cast brasses.
The graph bars on the material properties cards below compare C85400 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
Brinell Hardness
55
Elastic (Young's, Tensile) Modulus
100 GPa 15 x 106 psi
Elongation at Break
23 %
Poisson's Ratio
0.32
Shear Modulus
40 GPa 5.8 x 106 psi
Tensile Strength: Ultimate (UTS)
220 MPa 33 x 103 psi
Tensile Strength: Yield (Proof)
85 MPa 12 x 103 psi
Thermal Properties
Latent Heat of Fusion
180 J/g
Maximum Temperature: Mechanical
130 °C 270 °F
Melting Completion (Liquidus)
940 °C 1730 °F
Melting Onset (Solidus)
940 °C 1730 °F
Specific Heat Capacity
380 J/kg-K 0.090 BTU/lb-°F
Thermal Conductivity
89 W/m-K 51 BTU/h-ft-°F
Thermal Expansion
20 µm/m-K
Electrical Properties
Electrical Conductivity: Equal Volume
20 % IACS
Electrical Conductivity: Equal Weight (Specific)
22 % IACS
Otherwise Unclassified Properties
Base Metal Price
25 % relative
Density
8.3 g/cm3 520 lb/ft3
Embodied Carbon
2.8 kg CO2/kg material
Embodied Energy
46 MJ/kg 20 x 103 BTU/lb
Embodied Water
330 L/kg 39 gal/lb
Common Calculations
Resilience: Ultimate (Unit Rupture Work)
40 MJ/m3
Resilience: Unit (Modulus of Resilience)
35 kJ/m3
Stiffness to Weight: Axial
7.0 points
Stiffness to Weight: Bending
19 points
Strength to Weight: Axial
7.5 points
Strength to Weight: Bending
9.9 points
Thermal Diffusivity
28 mm2/s
Thermal Shock Resistance
7.6 points
Alloy Composition
Among cast copper alloys, the composition of C85400 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 | 65 to 70 | |
| Zn | 24 to 32 | |
| Pb | 1.5 to 3.8 | |
| Sn | 0.5 to 1.5 | |
| Ni | 0 to 1.0 | |
| Fe | 0 to 0.7 | |
| Al | 0 to 0.35 | |
| Si | 0 to 0.050 | |
| res. | 0 to 1.1 |
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
ASM Specialty Handbook: Copper and Copper Alloys, J. R. Davis (editor), 2001