UNS C37000 (CW607N) Free-Cutting Muntz Metal
C37000 Muntz Metal is a brass formulated for primary forming into wrought products. Cited properties are appropriate for the as-fabricated (no temper or treatment) condition. CW607N is the EN numeric designation for this material. C37000 is the UNS number. Additionally, the EN chemical designation is CuZn38Pb1. The British Standard (BS) designation is CZ129. And the common industry name is 60-39-1. Older literature may refer to this material as ASTM Alloy 6, 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 C37000 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
40 %
Poisson's Ratio
0.31
Rockwell B Hardness
45
Shear Modulus
39 GPa 5.7 x 106 psi
Shear Strength
270 MPa 40 x 103 psi
Tensile Strength: Ultimate (UTS)
400 MPa 58 x 103 psi
Tensile Strength: Yield (Proof)
160 MPa 23 x 103 psi
Thermal Properties
Latent Heat of Fusion
170 J/g
Maximum Temperature: Mechanical
120 °C 240 °F
Melting Completion (Liquidus)
900 °C 1650 °F
Melting Onset (Solidus)
890 °C 1630 °F
Specific Heat Capacity
380 J/kg-K 0.092 BTU/lb-°F
Thermal Conductivity
120 W/m-K 69 BTU/h-ft-°F
Thermal Expansion
21 µm/m-K
Electrical Properties
Electrical Conductivity: Equal Volume
27 % IACS
Electrical Conductivity: Equal Weight (Specific)
30 % IACS
Otherwise Unclassified Properties
Base Metal Price
23 % relative
Density
8.1 g/cm3 500 lb/ft3
Embodied Carbon
2.7 kg CO2/kg material
Embodied Energy
45 MJ/kg 19 x 103 BTU/lb
Embodied Water
320 L/kg 38 gal/lb
Common Calculations
Resilience: Ultimate (Unit Rupture Work)
130 MJ/m3
Resilience: Unit (Modulus of Resilience)
120 kJ/m3
Stiffness to Weight: Axial
7.2 points
Stiffness to Weight: Bending
19 points
Strength to Weight: Axial
14 points
Strength to Weight: Bending
15 points
Thermal Diffusivity
39 mm2/s
Thermal Shock Resistance
13 points
Alloy Composition
Among wrought copper alloys, the composition of C37000 Muntz Metal 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.
| Cu | 59 to 62 | |
| Zn | 36 to 40.2 | |
| Pb | 0.8 to 1.5 | |
| Fe | 0 to 0.15 | |
| res. | 0 to 0.4 |
All values are % weight. Ranges represent what is permitted under applicable standards.
Followup Questions
Similar Alloys
Further Reading
ASTM B124: Standard Specification for Copper and Copper Alloy Forging Rod, Bar, and Shapes
ASTM B283: Standard Specification for Copper and Copper-Alloy Die Forgings (Hot-Pressed)
ASM Specialty Handbook: Copper and Copper Alloys, J. R. Davis (editor), 2001