UNS C52100 (CW453K) Phosphor Bronze
C52100 bronze is a bronze formulated for primary forming into wrought products. CW453K is the EN numeric designation for this material. C52100 is the UNS number. Additionally, the EN chemical designation is CuSn8. And the British Standard (BS) designation is PB104. Older literature may refer to this material as ASTM Phosphor Bronze C, but this is now discouraged.
It has a moderately low heat capacity among wrought bronzes. In addition, it has a fairly high base cost and a moderately high embodied energy.
The properties of C52100 bronze include eight 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 C52100 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
45 to 100
Rockwell Superficial 30T Hardness
48 to 82
Shear Modulus
41 GPa 6.0 x 106 psi
Tensile Strength: Ultimate (UTS)
380 to 800 MPa 55 to 120 x 103 psi
Thermal Properties
Latent Heat of Fusion
200 J/g
Maximum Temperature: Mechanical
180 °C 350 °F
Melting Completion (Liquidus)
1030 °C 1880 °F
Melting Onset (Solidus)
880 °C 1620 °F
Specific Heat Capacity
370 J/kg-K 0.089 BTU/lb-°F
Thermal Conductivity
62 W/m-K 36 BTU/h-ft-°F
Thermal Expansion
18 µm/m-K
Electrical Properties
Electrical Conductivity: Equal Volume
13 % IACS
Electrical Conductivity: Equal Weight (Specific)
13 % IACS
Otherwise Unclassified Properties
Base Metal Price
34 % relative
Density
8.8 g/cm3 550 lb/ft3
Embodied Carbon
3.4 kg CO2/kg material
Embodied Energy
55 MJ/kg 24 x 103 BTU/lb
Embodied Water
370 L/kg 44 gal/lb
Common Calculations
Stiffness to Weight: Axial
7.0 points
Stiffness to Weight: Bending
18 points
Strength to Weight: Axial
12 to 25 points
Strength to Weight: Bending
13 to 22 points
Thermal Diffusivity
19 mm2/s
Thermal Shock Resistance
14 to 28 points
Alloy Composition
Among wrought copper alloys, the composition of C52100 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 | 89.8 to 93 | |
| Sn | 7.0 to 9.0 | |
| 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
Copper: Its Trade, Manufacture, Use, and Environmental Status, Gunter Joseph, 2001
Properties and Selection: Nonferrous Alloys and Special-Purpose Materials, ASM Handbook vol. 2, ASM International, 1993