Menu (ESC)

UNS C55181 (BCuP-2) Filler Metal

C55181 copper is a copper-based filler metal for brazing. Cited properties are appropriate for the as-fabricated (no temper or treatment) condition. BCuP-2 is the AWS designation for this material. C55181 is the UNS number.

It has the lowest embodied energy among the copper-based braze fillers in the database.

The graph bars on the material properties cards below compare C55181 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

110 GPa 16 x 106 psi

Poisson's Ratio


Shear Modulus

40 GPa 5.8 x 106 psi

Tensile Strength: Ultimate (UTS)

200 MPa 29 x 103 psi

Thermal Properties

Brazing Temperature

730 to 840 °C 1350 to 1550 °F

Latent Heat of Fusion

190 J/g

Maximum Temperature: Mechanical

200 °C 390 °F

Melting Completion (Liquidus)

790 °C 1460 °F

Melting Onset (Solidus)

710 °C 1310 °F

Specific Heat Capacity

410 J/kg-K 0.1 BTU/lb-°F

Thermal Expansion

16 µm/m-K

Otherwise Unclassified Properties

Base Metal Price

28 % relative


8.5 g/cm3 530 lb/ft3

Embodied Carbon

2.4 kg CO2/kg material

Embodied Energy

38 MJ/kg 16 x 103 BTU/lb

Embodied Water

290 L/kg 34 gal/lb

Common Calculations

Stiffness to Weight: Axial

7.0 points

Stiffness to Weight: Bending

19 points

Strength to Weight: Axial

6.5 points

Strength to Weight: Bending

8.9 points

Thermal Shock Resistance

8.2 points

Alloy Composition

Copper (Cu)Cu 92.4 to 93
Phosphorus (P)P 7.0 to 7.5
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