Menu (ESC)

UNS C55284 (BCuP-5) Filler Metal

C55284 copper is a copper-based filler metal for brazing. Cited properties are appropriate for the as-fabricated (no temper or treatment) condition. BCuP-5 is the AWS designation for this material. C55284 is the UNS number.

It has a moderately low tensile strength and the highest embodied energy among copper-based braze fillers.

The graph bars on the material properties cards below compare C55284 copper to: copper-based braze fillers (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 106 psi

Poisson's Ratio


Shear Modulus

38 GPa 5.6 x 106 psi

Tensile Strength: Ultimate (UTS)

180 MPa 26 x 103 psi

Thermal Properties

Brazing Temperature

700 to 820 °C 1300 to 1500 °F

Latent Heat of Fusion

180 J/g

Maximum Temperature: Mechanical

200 °C 390 °F

Melting Completion (Liquidus)

800 °C 1480 °F

Melting Onset (Solidus)

640 °C 1190 °F

Specific Heat Capacity

380 J/kg-K 0.091 BTU/lb-°F

Thermal Expansion

17 µm/m-K

Otherwise Unclassified Properties


8.9 g/cm3 550 lb/ft3

Embodied Carbon

16 kg CO2/kg material

Embodied Energy

260 MJ/kg 110 x 103 BTU/lb

Common Calculations

Stiffness to Weight: Axial

6.5 points

Stiffness to Weight: Bending

18 points

Strength to Weight: Axial

5.6 points

Strength to Weight: Bending

8.0 points

Thermal Shock Resistance

7.4 points

Alloy Composition

Copper (Cu)Cu 79.2 to 80.7
Silver (Ag)Ag 14.5 to 15.5
Phosphorus (P)P 4.8 to 5.2
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

Properties and Selection: Nonferrous Alloys and Special-Purpose Materials, ASM Handbook vol. 2, ASM International, 1993