UNS C69430 Silicon Red Brass
C69430 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 among wrought brasses. In addition, it has a moderately low electrical conductivity and a moderately low melting temperature.
The graph bars on the material properties cards below compare C69430 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
17 %
Poisson's Ratio
0.33
Shear Modulus
42 GPa 6.0 x 106 psi
Shear Strength
350 MPa 51 x 103 psi
Tensile Strength: Ultimate (UTS)
570 MPa 83 x 103 psi
Tensile Strength: Yield (Proof)
280 MPa 40 x 103 psi
Thermal Properties
Latent Heat of Fusion
260 J/g
Maximum Temperature: Mechanical
170 °C 340 °F
Melting Completion (Liquidus)
920 °C 1680 °F
Melting Onset (Solidus)
820 °C 1510 °F
Specific Heat Capacity
410 J/kg-K 0.1 BTU/lb-°F
Thermal Conductivity
26 W/m-K 15 BTU/h-ft-°F
Thermal Expansion
18 µm/m-K
Electrical Properties
Electrical Conductivity: Equal Volume
6.2 % IACS
Electrical Conductivity: Equal Weight (Specific)
6.7 % IACS
Otherwise Unclassified Properties
Base Metal Price
27 % 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
300 L/kg 36 gal/lb
Common Calculations
Resilience: Ultimate (Unit Rupture Work)
80 MJ/m3
Resilience: Unit (Modulus of Resilience)
340 kJ/m3
Stiffness to Weight: Axial
7.4 points
Stiffness to Weight: Bending
19 points
Strength to Weight: Axial
19 points
Strength to Weight: Bending
18 points
Thermal Diffusivity
7.7 mm2/s
Thermal Shock Resistance
20 points
Alloy Composition
Among wrought copper alloys, the composition of C69430 brass is notable for including arsenic (As) and silicon (Si). Arsenic is used to protect the alloy against dezincification. Silicon is used to increase strength at the expense of ductility. It also lowers the melting temperature and raises the fluidity of the alloy.
| Cu | 80 to 83 | |
| Zn | 11.4 to 16.5 | |
| Si | 3.5 to 4.5 | |
| Pb | 0 to 0.3 | |
| Fe | 0 to 0.2 | |
| As | 0.030 to 0.060 | |
| 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