# UNS C69710 Leaded Silicon Brass

C69710 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 electrical conductivity among wrought brasses. In addition, it has a moderately low thermal conductivity and a moderately high tensile strength.

The graph bars on the material properties cards below compare C69710 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

40 *W/m-K* 23 *BTU/h-ft-°F*

Thermal Expansion

19 *µm/m-K*

## Electrical Properties

Electrical Conductivity: Equal Volume

8.0 *% IACS*

Electrical Conductivity: Equal Weight (Specific)

8.7 *% IACS*

## 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

12 *mm ^{2}/s*

Thermal Shock Resistance

16 *points*

## Alloy Composition

Among wrought copper alloys, the composition of C69710 brass is notable for including arsenic (As) and silicon (Si). Arsenic is used to protect the alloy against dezincification. Silicon is used to increase strength at the expense of ductility. It also lowers the melting temperature and raises the fluidity of the alloy.

Cu | 75 to 80 | |

Zn | 13.8 to 22 | |

Si | 2.5 to 3.5 | |

Pb | 0.5 to 1.5 | |

Mn | 0 to 0.4 | |

Fe | 0 to 0.2 | |

As | 0.030 to 0.060 | |

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