UNS C92200 (CB498K) Navy-M Leaded Bronze
C92200 bronze is a bronze formulated for casting. Cited properties are appropriate for the as-fabricated (no temper or treatment) condition. CB498K is the EN numeric designation for this material. C92200 is the UNS number. Additionally, the EN chemical designation is CuSn6Zn4Pb2. Older literature may refer to this material as ASTM Alloy 2A, but this is now discouraged.
It has a very high ductility among cast bronzes. In addition, it has a fairly high electrical conductivity and a moderately low melting temperature.
The graph bars on the material properties cards below compare C92200 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
Compressive (Crushing) Strength
180 MPa 26 x 103 psi
Elastic (Young's, Tensile) Modulus
110 GPa 16 x 106 psi
Elongation at Break
25 %
Fatigue Strength
76 MPa 11 x 103 psi
Poisson's Ratio
0.34
Rockwell B Hardness
65
Shear Modulus
41 GPa 5.9 x 106 psi
Tensile Strength: Ultimate (UTS)
280 MPa 40 x 103 psi
Tensile Strength: Yield (Proof)
140 MPa 20 x 103 psi
Thermal Properties
Latent Heat of Fusion
190 J/g
Maximum Temperature: Mechanical
170 °C 340 °F
Melting Completion (Liquidus)
990 °C 1810 °F
Melting Onset (Solidus)
830 °C 1520 °F
Solidification (Pattern Maker's) Shrinkage
1.6 %
Specific Heat Capacity
370 J/kg-K 0.089 BTU/lb-°F
Thermal Conductivity
70 W/m-K 40 BTU/h-ft-°F
Thermal Expansion
19 µm/m-K
Electrical Properties
Electrical Conductivity: Equal Volume
14 % IACS
Electrical Conductivity: Equal Weight (Specific)
14 % IACS
Otherwise Unclassified Properties
Base Metal Price
32 % relative
Density
8.7 g/cm3 540 lb/ft3
Embodied Carbon
3.2 kg CO2/kg material
Embodied Energy
52 MJ/kg 22 x 103 BTU/lb
Embodied Water
360 L/kg 43 gal/lb
Common Calculations
Resilience: Ultimate (Unit Rupture Work)
58 MJ/m3
Resilience: Unit (Modulus of Resilience)
87 kJ/m3
Stiffness to Weight: Axial
6.9 points
Stiffness to Weight: Bending
18 points
Strength to Weight: Axial
8.9 points
Strength to Weight: Bending
11 points
Thermal Diffusivity
21 mm2/s
Thermal Shock Resistance
9.9 points
Alloy Composition
Among cast copper alloys, the composition of C92200 bronze is notable for containing a comparatively high amount of lead (Pb) and including sulfur (S). Lead is used to improve machinability and bearing properties, at the cost of toxicity. It also adds pressure tightness to castings. Sulfur is used to improve machinability at the cost of a decrease in electrical conductivity.
| Cu | 86 to 90 | |
| Sn | 5.5 to 6.5 | |
| Zn | 3.0 to 5.0 | |
| Pb | 1.0 to 2.0 | |
| P | 0 to 1.5 | |
| Ni | 0 to 1.0 | |
| Fe | 0 to 0.25 | |
| Sb | 0 to 0.25 | |
| S | 0 to 0.050 | |
| Si | 0 to 0.0050 | |
| Al | 0 to 0.0050 | |
| res. | 0 to 0.7 |
All values are % weight. Ranges represent what is permitted under applicable standards.
Followup Questions
Similar Alloys
Further Reading
ASTM B271: Standard Specification for Copper-Base Alloy Centrifugal Castings
ASTM B505: Standard Specification for Copper Alloy Continuous Castings
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