UNS C52400 Phosphor Bronze
C52400 bronze is a bronze formulated for primary forming into wrought products. C52400 is the UNS number for this material. Older literature may refer to this material as ASTM Phosphor Bronze D, but this is now discouraged.
It has a fairly high base cost among wrought bronzes. In addition, it has a fairly low melting temperature and a moderately low heat capacity.
The properties of C52400 bronze include seven common variations. This page shows summary ranges across all of them. For more specific values, follow the links immediately below. The graph bars on the material properties cards further below compare C52400 bronze to: wrought 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
Poisson's Ratio
0.34
Rockwell B Hardness
50 to 100
Rockwell Superficial 30T Hardness
54 to 84
Shear Modulus
41 GPa 5.9 x 106 psi
Tensile Strength: Ultimate (UTS)
450 to 880 MPa 65 to 130 x 103 psi
Thermal Properties
Latent Heat of Fusion
190 J/g
Maximum Temperature: Mechanical
170 °C 340 °F
Melting Completion (Liquidus)
1000 °C 1830 °F
Melting Onset (Solidus)
840 °C 1550 °F
Specific Heat Capacity
370 J/kg-K 0.088 BTU/lb-°F
Thermal Conductivity
50 W/m-K 29 BTU/h-ft-°F
Thermal Expansion
18 µm/m-K
Electrical Properties
Electrical Conductivity: Equal Volume
11 % IACS
Electrical Conductivity: Equal Weight (Specific)
11 % IACS
Otherwise Unclassified Properties
Base Metal Price
35 % relative
Density
8.8 g/cm3 550 lb/ft3
Embodied Carbon
3.6 kg CO2/kg material
Embodied Energy
58 MJ/kg 25 x 103 BTU/lb
Embodied Water
390 L/kg 46 gal/lb
Common Calculations
Stiffness to Weight: Axial
6.9 points
Stiffness to Weight: Bending
18 points
Strength to Weight: Axial
14 to 28 points
Strength to Weight: Bending
15 to 23 points
Thermal Diffusivity
15 mm2/s
Thermal Shock Resistance
17 to 32 points
Alloy Composition
Among wrought copper alloys, the composition of C52400 bronze is notable for including phosphorus (P) and tin (Sn). Phosphorus is used as an alloy deoxidizer, and to reduce vulnerability to dezincification. Tin is used to improve strength, bearing properties, and corrosion resistance against certain types of media.
| Cu | 87.8 to 91 | |
| Sn | 9.0 to 11 | |
| P | 0.030 to 0.35 | |
| Zn | 0 to 0.2 | |
| Fe | 0 to 0.1 | |
| Pb | 0 to 0.050 | |
| res. | 0 to 0.5 |
All values are % weight. Ranges represent what is permitted under applicable standards.
Followup Questions
Similar Alloys
Further Reading
ASTM B139: Standard Specification for Phosphor Bronze Rod, Bar, and Shapes
ASTM B103: Standard Specification for Phosphor Bronze Plate, Sheet, Strip, and Rolled Bar
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