# UNS C38000 (CW624N) Leaded Brass

C38000 brass is a brass formulated for primary forming into wrought products. Cited properties are appropriate for the M20 (as hot rolled) condition. CW624N is the EN numeric designation for this material. C38000 is the UNS number. Additionally, the EN chemical designation is CuZn43Pb2Al.

It has a moderately low base cost among wrought brasses. In addition, it has the lowest melting temperature and a moderately low tensile strength.

The graph bars on the material properties cards below compare C38000 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

100 *GPa* 15 *x 10 ^{6} psi*

Elongation at Break

17 *%*

Poisson's Ratio

0.31

Shear Modulus

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

Shear Strength

230 *MPa* 34 *x 10 ^{3} psi*

Tensile Strength: Ultimate (UTS)

380 *MPa* 55 *x 10 ^{3} psi*

Tensile Strength: Yield (Proof)

120 *MPa* 18 *x 10 ^{3} psi*

## Thermal Properties

Latent Heat of Fusion

170 *J/g*

Maximum Temperature: Mechanical

110 *°C* 230 *°F*

Melting Completion (Liquidus)

800 *°C* 1470 *°F*

Melting Onset (Solidus)

760 *°C* 1400 *°F*

Specific Heat Capacity

380 *J/kg-K* 0.091 *BTU/lb-°F*

Thermal Conductivity

110 *W/m-K* 66 *BTU/h-ft-°F*

Thermal Expansion

21 *µm/m-K*

## Otherwise Unclassified Properties

Base Metal Price

22 *% relative*

Density

8.0 *g/cm ^{3}* 500

*lb/ft*

^{3}Embodied Carbon

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

Embodied Energy

46 *MJ/kg* 20 *x 10 ^{3} BTU/lb*

Embodied Water

330 *L/kg* 39 *gal/lb*

## Common Calculations

Resilience: Ultimate (Unit Rupture Work)

50 *MJ/m ^{3}*

Resilience: Unit (Modulus of Resilience)

74 *kJ/m ^{3}*

Stiffness to Weight: Axial

7.1 *points*

Stiffness to Weight: Bending

19 *points*

Strength to Weight: Axial

13 *points*

Strength to Weight: Bending

14 *points*

Thermal Diffusivity

37 *mm ^{2}/s*

Thermal Shock Resistance

13 *points*

## Alloy Composition

Among wrought copper alloys, the composition of C38000 brass is notable for including aluminum (Al) and containing a comparatively high amount of lead (Pb). Aluminum is used to add strength and oxidation resistance. Lead is used to improve machinability and bearing properties, at the cost of toxicity.

Cu | 55 to 60 | |

Zn | 35.9 to 43.5 | |

Pb | 1.5 to 2.5 | |

Al | 0 to 0.5 | |

Fe | 0 to 0.35 | |

Sn | 0 to 0.3 | |

res. | 0 to 0.5 |

All values are % weight. Ranges represent what is permitted under applicable standards.

## Followup Questions

## Similar Alloys

## Further Reading

ASTM B455: Standard Specification for Copper-Zinc-Lead Alloy (Leaded-Brass) Extruded Shapes

ASM Specialty Handbook: Copper and Copper Alloys, J. R. Davis (editor), 2001