# AWS BAg-4 (P07400) Filler Metal

AWS BAg-4 is a silver-based filler metal for brazing. Cited properties are appropriate for the as-fabricated (no temper or treatment) condition. BAg-4 is the AWS designation for this material. P07400 is the UNS number.

It has a fairly high heat capacity among silver-based braze fillers. In addition, it has a moderately low tensile strength and a moderately low density.

The graph bars on the material properties cards below compare AWS BAg-4 to: silver-based braze fillers (top), all alloys in the same category (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

91 *GPa* 13 *x 10 ^{6} psi*

Poisson's Ratio

0.33

Shear Modulus

34 *GPa* 5.0 *x 10 ^{6} psi*

Tensile Strength: Ultimate (UTS)

150 *MPa* 22 *x 10 ^{3} psi*

## Thermal Properties

Brazing Temperature

740 to 900 *°C* 1370 to 1650 *°F*

Latent Heat of Fusion

140 *J/g*

Melting Completion (Liquidus)

780 *°C* 1430 *°F*

Melting Onset (Solidus)

670 *°C* 1240 *°F*

Specific Heat Capacity

330 *J/kg-K* 0.078 *BTU/lb-°F*

Thermal Expansion

21 *µm/m-K*

## Otherwise Unclassified Properties

Density

8.9 *g/cm ^{3}* 550

*lb/ft*

^{3}Embodied Carbon

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

Embodied Energy

630 *MJ/kg* 270 *x 10 ^{3} BTU/lb*

## Common Calculations

Stiffness to Weight: Axial

5.7 *points*

Stiffness to Weight: Bending

17 *points*

Strength to Weight: Axial

4.7 *points*

Strength to Weight: Bending

7.1 *points*

Thermal Shock Resistance

5.7 *points*

## Alloy Composition

Ag | 39 to 41 | |

Cu | 29 to 31 | |

Zn | 26 to 30 | |

Ni | 1.5 to 2.5 | |

res. | 0 to 0.15 |

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

## Followup Questions

## Similar Alloys

## Further Reading

AWS A5.8: Specification for Filler Metals for Brazing and Braze Welding