Menu (ESC)

AWS BAu-2 (P00800) Filler Metal

AWS BAu-2 is a gold-based filler metal for brazing. Cited properties are appropriate for the as-fabricated (no temper or treatment) condition. BAu-2 is the AWS designation for this material. P00800 is the UNS number.

It has a fairly low melting temperature among gold-based braze fillers. In addition, it has a moderately low heat capacity and a moderately low tensile strength.

The graph bars on the material properties cards below compare AWS BAu-2 to: gold-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.

Thermal Properties

Brazing Temperature

890 to 1010 °C 1640 to 1850 °F

Latent Heat of Fusion

92 J/g

Melting Completion (Liquidus)

890 °C 1640 °F

Melting Onset (Solidus)

890 °C 1640 °F

Specific Heat Capacity

180 J/kg-K 0.043 BTU/lb-°F

Thermal Expansion

15 µm/m-K

Other Material Properties


17 g/cm3 1080 lb/ft3

Elastic (Young's, Tensile) Modulus

100 GPa 15 x 106 psi

Poisson's Ratio


Shear Modulus

36 GPa 5.3 x 106 psi

Tensile Strength: Ultimate (UTS)

150 MPa 22 x 103 psi

Common Calculations

Stiffness to Weight: Axial

3.3 points

Stiffness to Weight: Bending

9.1 points

Strength to Weight: Axial

2.4 points

Strength to Weight: Bending

3.6 points

Thermal Shock Resistance

7.1 points

Alloy Composition

Gold (Au)Au 79.5 to 80.5
Copper (Cu)Cu 19.4 to 20.5
Residualsres. 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