UNS C69700 Leaded Silicon Brass
C69700 brass is a brass formulated for primary forming into wrought products. Cited properties are appropriate for the H04 (full hard) temper. It has a moderately low thermal conductivity and a moderately high tensile strength among wrought brasses.
The graph bars on the material properties cards below compare C69700 brass to: wrought 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
110 GPa 16 x 106 psi
Elongation at Break
25 %
Poisson's Ratio
0.32
Shear Modulus
41 GPa 6.0 x 106 psi
Shear Strength
300 MPa 44 x 103 psi
Tensile Strength: Ultimate (UTS)
470 MPa 68 x 103 psi
Tensile Strength: Yield (Proof)
230 MPa 34 x 103 psi
Thermal Properties
Latent Heat of Fusion
240 J/g
Maximum Temperature: Mechanical
160 °C 320 °F
Melting Completion (Liquidus)
930 °C 1710 °F
Melting Onset (Solidus)
880 °C 1620 °F
Specific Heat Capacity
400 J/kg-K 0.1 BTU/lb-°F
Thermal Conductivity
43 W/m-K 25 BTU/h-ft-°F
Thermal Expansion
19 µm/m-K
Otherwise Unclassified Properties
Base Metal Price
26 % relative
Density
8.3 g/cm3 520 lb/ft3
Embodied Carbon
2.7 kg CO2/kg material
Embodied Energy
44 MJ/kg 19 x 103 BTU/lb
Embodied Water
310 L/kg 37 gal/lb
Common Calculations
Resilience: Ultimate (Unit Rupture Work)
99 MJ/m3
Resilience: Unit (Modulus of Resilience)
250 kJ/m3
Stiffness to Weight: Axial
7.3 points
Stiffness to Weight: Bending
19 points
Strength to Weight: Axial
16 points
Strength to Weight: Bending
16 points
Thermal Diffusivity
13 mm2/s
Thermal Shock Resistance
16 points
Alloy Composition
Among wrought copper alloys, the composition of C69700 brass is notable for including silicon (Si) and manganese (Mn). Silicon is used to increase strength at the expense of ductility. It also lowers the melting temperature and raises the fluidity of the alloy. Manganese is used to improve strength without a proportional reduction in ductility.
| Cu | 75 to 80 | |
| Zn | 13.9 to 22 | |
| Si | 2.5 to 3.5 | |
| Pb | 0.5 to 1.5 | |
| Mn | 0 to 0.4 | |
| Fe | 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 B371: Standard Specification for Copper-Zinc-Silicon Alloy Rod
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