UNS C65500 (CW116C) Silicon Bronze
C65500 bronze is a bronze formulated for primary forming into wrought products. CW116C is the EN numeric designation for this material. C65500 is the UNS number. Additionally, the EN chemical designation is CuSi3Mn1. The British Standard (BS) designation is CS101. And the common industry name is High-Silicon Bronze A.
It has a moderately low electrical conductivity among wrought bronzes. In addition, it can have the highest ductility and has a moderately low embodied energy.
The properties of C65500 bronze include eleven 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 C65500 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
120 GPa 17 x 106 psi
Elongation at Break
4.0 to 70 %
Poisson's Ratio
0.34
Rockwell B Hardness
62 to 97
Shear Modulus
43 GPa 6.3 x 106 psi
Shear Strength
260 to 440 MPa 38 to 63 x 103 psi
Tensile Strength: Ultimate (UTS)
360 to 760 MPa 52 to 110 x 103 psi
Tensile Strength: Yield (Proof)
120 to 430 MPa 17 to 62 x 103 psi
Thermal Properties
Latent Heat of Fusion
260 J/g
Maximum Temperature: Mechanical
200 °C 390 °F
Melting Completion (Liquidus)
1030 °C 1880 °F
Melting Onset (Solidus)
970 °C 1780 °F
Specific Heat Capacity
400 J/kg-K 0.1 BTU/lb-°F
Thermal Conductivity
36 W/m-K 21 BTU/h-ft-°F
Thermal Expansion
18 µm/m-K
Electrical Properties
Electrical Conductivity: Equal Volume
7.0 % IACS
Electrical Conductivity: Equal Weight (Specific)
7.3 % IACS
Otherwise Unclassified Properties
Base Metal Price
29 % relative
Calomel Potential
-270 mV
Density
8.6 g/cm3 540 lb/ft3
Embodied Carbon
2.7 kg CO2/kg material
Embodied Energy
42 MJ/kg 18 x 103 BTU/lb
Embodied Water
300 L/kg 36 gal/lb
Common Calculations
Resilience: Ultimate (Unit Rupture Work)
11 to 450 MJ/m3
Resilience: Unit (Modulus of Resilience)
62 to 790 kJ/m3
Stiffness to Weight: Axial
7.5 points
Stiffness to Weight: Bending
19 points
Strength to Weight: Axial
12 to 24 points
Strength to Weight: Bending
13 to 21 points
Thermal Diffusivity
10 mm2/s
Thermal Shock Resistance
12 to 26 points
Alloy Composition
Among wrought copper alloys, the composition of C65500 bronze is notable for including silicon (Si) and manganese (Mn). Silicon is used to increase strength at the expense of ductility. It also lowers the melting temperature and raises the fluidity of the alloy. Manganese is used to improve strength without a proportional reduction in ductility.
| Cu | 91.5 to 96.7 | |
| Si | 2.8 to 3.8 | |
| Mn | 0.5 to 1.3 | |
| Zn | 0 to 1.5 | |
| Fe | 0 to 0.8 | |
| Ni | 0 to 0.6 | |
| 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 B98: Standard Specification for Copper-Silicon Alloy Rod, Bar and Shapes
ASTM B96: Standard Specification for Copper-Silicon Alloy Plate, Sheet, Strip, and Rolled Bar for General Purposes and Pressure Vessels
ASTM B124: Standard Specification for Copper and Copper Alloy Forging Rod, Bar, and Shapes
ASTM B283: Standard Specification for Copper and Copper-Alloy Die Forgings (Hot-Pressed)
Copper: Its Trade, Manufacture, Use, and Environmental Status, Gunter Joseph, 2001
Pressure Vessels: External Pressure Technology, 2nd ed., Carl T. F. Ross, 2011
Properties and Selection: Nonferrous Alloys and Special-Purpose Materials, ASM Handbook vol. 2, ASM International, 1993