# 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 10 ^{6} psi*

Elongation at Break

40 *%*

Poisson's Ratio

0.31

Rockwell B Hardness

45

Shear Modulus

39 *GPa* 5.7 *x 10 ^{6} psi*

Shear Strength

270 *MPa* 40 *x 10 ^{3} psi*

Tensile Strength: Ultimate (UTS)

400 *MPa* 58 *x 10 ^{3} psi*

Tensile Strength: Yield (Proof)

160 *MPa* 23 *x 10 ^{3} 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/cm ^{3}* 500

*lb/ft*

^{3}Embodied Carbon

2.7 *kg CO _{2}/kg material*

Embodied Energy

45 *MJ/kg* 19 *x 10 ^{3} BTU/lb*

Embodied Water

320 *L/kg* 38 *gal/lb*

## Common Calculations

Resilience: Ultimate (Unit Rupture Work)

130 *MJ/m ^{3}*

Resilience: Unit (Modulus of Resilience)

120 *kJ/m ^{3}*

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 *mm ^{2}/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