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UNS C89320 Bismuth Bronze

C89320 bronze is a bronze formulated for casting. Cited properties are appropriate for the as-fabricated (no temper or treatment) condition. It has a very high base cost among cast bronzes. In addition, it has a fairly high electrical conductivity and a moderately low heat capacity.

The graph bars on the material properties cards below compare C89320 bronze to: cast bronzes (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

Elongation at Break

17 %

Poisson's Ratio


Shear Modulus

40 GPa 5.8 x 106 psi

Tensile Strength: Ultimate (UTS)

270 MPa 39 x 103 psi

Tensile Strength: Yield (Proof)

140 MPa 21 x 103 psi

Thermal Properties

Latent Heat of Fusion

190 J/g

Maximum Temperature: Mechanical

180 °C 360 °F

Melting Completion (Liquidus)

1050 °C 1910 °F

Melting Onset (Solidus)

930 °C 1700 °F

Specific Heat Capacity

360 J/kg-K 0.087 BTU/lb-°F

Thermal Conductivity

56 W/m-K 32 BTU/h-ft-°F

Thermal Expansion

17 µm/m-K

Electrical Properties

Electrical Conductivity: Equal Volume

15 % IACS

Electrical Conductivity: Equal Weight (Specific)

15 % IACS

Otherwise Unclassified Properties

Base Metal Price

37 % relative


8.9 g/cm3 550 lb/ft3

Embodied Carbon

3.5 kg CO2/kg material

Embodied Energy

56 MJ/kg 24 x 103 BTU/lb

Embodied Water

490 L/kg 58 gal/lb

Common Calculations

Resilience: Ultimate (Unit Rupture Work)

38 MJ/m3

Resilience: Unit (Modulus of Resilience)

93 kJ/m3

Stiffness to Weight: Axial

6.8 points

Stiffness to Weight: Bending

18 points

Strength to Weight: Axial

8.5 points

Strength to Weight: Bending

10 points

Thermal Diffusivity

17 mm2/s

Thermal Shock Resistance

10 points

Alloy Composition

Among cast copper alloys, the composition of C89320 bronze is notable for including bismuth (Bi). Bismuth improves machinability and pressure tightness. It is used a non-toxic but more expensive replacement for lead.

Copper (Cu) 87 to 91
Tin (Sn) 5.0 to 7.0
Bismuth (Bi) 4.0 to 6.0
Nickel (Ni) 0 to 1.0
Zinc (Zn) 0 to 1.0
Antimony (Sb) 0 to 0.35
Phosphorus (P) 0 to 0.3
Iron (Fe) 0 to 0.2
Lead (Pb) 0 to 0.090
Sulfur (S) 0 to 0.080
Silicon (Si) 0 to 0.0050
Aluminum (Al) 0 to 0.0050
Residuals 0 to 0.5

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

Followup Questions

Similar Alloys

Further Reading

ASTM B505: Standard Specification for Copper Alloy Continuous Castings

ASM Specialty Handbook: Copper and Copper Alloys, J. R. Davis (editor), 2001

CRC Materials Science and Engineering Handbook, 4th ed., James F. Shackelford et al. (editors), 2015