# UNS C69700 Leaded Silicon Brass

C69700 brass is a brass formulated for primary forming into wrought products. Cited properties are appropriate for the H04 (full hard) temper. It has a moderately low thermal conductivity and a moderately high tensile strength among wrought brasses.

The graph bars on the material properties cards below compare C69700 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 10 ^{6} psi*

Elongation at Break

25 *%*

Poisson's Ratio

0.32

Shear Modulus

41 *GPa* 6.0 *x 10 ^{6} psi*

Shear Strength

300 *MPa* 44 *x 10 ^{3} psi*

Tensile Strength: Ultimate (UTS)

470 *MPa* 68 *x 10 ^{3} psi*

Tensile Strength: Yield (Proof)

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

## Thermal Properties

Latent Heat of Fusion

240 *J/g*

Maximum Temperature: Mechanical

160 *°C* 320 *°F*

Melting Completion (Liquidus)

930 *°C* 1710 *°F*

Melting Onset (Solidus)

880 *°C* 1620 *°F*

Specific Heat Capacity

400 *J/kg-K* 0.1 *BTU/lb-°F*

Thermal Conductivity

43 *W/m-K* 25 *BTU/h-ft-°F*

Thermal Expansion

19 *µm/m-K*

## Otherwise Unclassified Properties

Base Metal Price

26 *% relative*

Density

8.3 *g/cm ^{3}* 520

*lb/ft*

^{3}Embodied Carbon

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

Embodied Energy

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

Embodied Water

310 *L/kg* 37 *gal/lb*

## Common Calculations

Resilience: Ultimate (Unit Rupture Work)

99 *MJ/m ^{3}*

Resilience: Unit (Modulus of Resilience)

250 *kJ/m ^{3}*

Stiffness to Weight: Axial

7.3 *points*

Stiffness to Weight: Bending

19 *points*

Strength to Weight: Axial

16 *points*

Strength to Weight: Bending

16 *points*

Thermal Diffusivity

13 *mm ^{2}/s*

Thermal Shock Resistance

16 *points*

## Alloy Composition

Among wrought copper alloys, the composition of C69700 brass is notable for including silicon (Si) and manganese (Mn). Silicon is used to increase strength at the expense of ductility. It also lowers the melting temperature and raises the fluidity of the alloy. Manganese is used to improve strength without a proportional reduction in ductility.

Cu | 75 to 80 | |

Zn | 13.9 to 22 | |

Si | 2.5 to 3.5 | |

Pb | 0.5 to 1.5 | |

Mn | 0 to 0.4 | |

Fe | 0 to 0.2 | |

res. | 0 to 0.5 |

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

## Followup Questions

## Similar Alloys

## Further Reading

ASTM B371: Standard Specification for Copper-Zinc-Silicon Alloy Rod

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

CRC Materials Science and Engineering Handbook, 4th ed., James F. Shackelford et al. (editors), 2015