UNS C44300 (CW706R) Admiralty Brass
C44300 brass is a brass formulated for primary forming into wrought products. Cited properties are appropriate for the O61 (annealed) temper. CW706R is the EN numeric designation for this material. C44300 is the UNS number. Additionally, the EN chemical designation is CuZn20Al2As. The British Standard (BS) designation is CZ111. And the common industry name is 71.5-27.5-1. Older literature may refer to this material as ASTM Admiralty Metal Type B, but this is now discouraged.
It has a moderately low tensile strength among the wrought brasses in the database.
The graph bars on the material properties cards below compare C44300 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
Poisson's Ratio
0.32
Shear Modulus
41 GPa 5.9 x 106 psi
Tensile Strength: Ultimate (UTS)
350 MPa 51 x 103 psi
Tensile Strength: Yield (Proof)
120 MPa 17 x 103 psi
Thermal Properties
Latent Heat of Fusion
180 J/g
Maximum Temperature: Mechanical
140 °C 290 °F
Melting Completion (Liquidus)
940 °C 1720 °F
Melting Onset (Solidus)
900 °C 1650 °F
Specific Heat Capacity
380 J/kg-K 0.092 BTU/lb-°F
Thermal Conductivity
110 W/m-K 64 BTU/h-ft-°F
Thermal Expansion
20 µm/m-K
Electrical Properties
Electrical Conductivity: Equal Volume
25 % IACS
Electrical Conductivity: Equal Weight (Specific)
27 % IACS
Otherwise Unclassified Properties
Base Metal Price
26 % 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: Unit (Modulus of Resilience)
65 kJ/m3
Stiffness to Weight: Axial
7.2 points
Stiffness to Weight: Bending
19 points
Strength to Weight: Axial
12 points
Strength to Weight: Bending
13 points
Thermal Diffusivity
35 mm2/s
Thermal Shock Resistance
12 points
Alloy Composition
Among wrought copper alloys, the composition of C44300 brass is notable for including arsenic (As). Arsenic is used to protect the alloy against dezincification.
| Cu | 70 to 73 | |
| Zn | 25.2 to 29.1 | |
| Sn | 0.9 to 1.2 | |
| As | 0.020 to 0.060 | |
| Pb | 0 to 0.070 | |
| Fe | 0 to 0.060 | |
| res. | 0 to 0.4 |
All values are % weight. Ranges represent what is permitted under applicable standards.
Followup Questions
Similar Alloys
Further Reading
ASTM B111: Standard Specification for Copper and Copper-Alloy Seamless Condenser Tubes and Ferrule Stock
ASM Specialty Handbook: Copper and Copper Alloys, J. R. Davis (editor), 2001