UNS C28000 (CW509L) Muntz Metal
C28000 Muntz Metal is a brass formulated for primary forming into wrought products. CW509L is the EN numeric designation for this material. C28000 is the UNS number. Additionally, the EN chemical designation is CuZn40. The British Standard (BS) designation is CZ109. And the common industry name is 60-40 Muntz Metal.
The properties of C28000 Muntz Metal include eight common variations. This page shows summary ranges across all of them. For more specific values, follow the links immediately below. The graph bars on the material properties cards further below compare C28000 Muntz Metal 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
100 GPa 15 x 106 psi
Elongation at Break
10 to 45 %
Poisson's Ratio
0.31
Rockwell B Hardness
55 to 78
Shear Modulus
40 GPa 5.8 x 106 psi
Shear Strength
230 to 330 MPa 33 to 48 x 103 psi
Tensile Strength: Ultimate (UTS)
330 to 610 MPa 47 to 88 x 103 psi
Tensile Strength: Yield (Proof)
150 to 370 MPa 22 to 54 x 103 psi
Thermal Properties
Latent Heat of Fusion
170 J/g
Maximum Temperature: Mechanical
120 °C 250 °F
Melting Completion (Liquidus)
900 °C 1660 °F
Melting Onset (Solidus)
900 °C 1650 °F
Specific Heat Capacity
390 J/kg-K 0.092 BTU/lb-°F
Thermal Conductivity
120 W/m-K 71 BTU/h-ft-°F
Thermal Expansion
21 µm/m-K
Electrical Properties
Electrical Conductivity: Equal Volume
28 % IACS
Electrical Conductivity: Equal Weight (Specific)
31 % IACS
Otherwise Unclassified Properties
Base Metal Price
23 % relative
Density
8.0 g/cm3 500 lb/ft3
Embodied Carbon
2.7 kg CO2/kg material
Embodied Energy
46 MJ/kg 20 x 103 BTU/lb
Embodied Water
320 L/kg 38 gal/lb
Common Calculations
Resilience: Ultimate (Unit Rupture Work)
27 to 240 MJ/m3
Resilience: Unit (Modulus of Resilience)
110 to 670 kJ/m3
Stiffness to Weight: Axial
7.2 points
Stiffness to Weight: Bending
20 points
Strength to Weight: Axial
11 to 21 points
Strength to Weight: Bending
13 to 20 points
Thermal Diffusivity
40 mm2/s
Thermal Shock Resistance
11 to 20 points
Alloy Composition
Among wrought copper alloys, the composition of C28000 Muntz Metal is notable for containing comparatively high amounts of lead (Pb) and iron (Fe). Lead is used to improve machinability and bearing properties, at the cost of toxicity. Iron is used to increase strength inexpensively.
| Cu | 59 to 63 | |
| Zn | 36.3 to 41 | |
| Pb | 0 to 0.3 | |
| Fe | 0 to 0.070 | |
| res. | 0 to 0.3 |
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
ASTM B36: Standard Specification for Brass Plate, Sheet, Strip, And Rolled Bar
Copper: Its Trade, Manufacture, Use, and Environmental Status, Gunter Joseph, 2001
Properties and Selection: Nonferrous Alloys and Special-Purpose Materials, ASM Handbook vol. 2, ASM International, 1993