UNS C93600 Leaded Tin Bronze
C93600 bronze is a bronze formulated for casting. Cited properties are appropriate for the as-fabricated (no temper or treatment) condition. C93600 is the UNS number for this material. Additionally, the common industry name is 81-7-12.
It has a fairly low heat capacity among cast bronzes. In addition, it has a moderately low melting temperature and a moderately low tensile strength.
The graph bars on the material properties cards below compare C93600 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
99 GPa 14 x 106 psi
Elongation at Break
14 %
Poisson's Ratio
0.35
Shear Modulus
36 GPa 5.3 x 106 psi
Tensile Strength: Ultimate (UTS)
260 MPa 37 x 103 psi
Tensile Strength: Yield (Proof)
140 MPa 20 x 103 psi
Thermal Properties
Latent Heat of Fusion
170 J/g
Maximum Temperature: Mechanical
150 °C 290 °F
Melting Completion (Liquidus)
940 °C 1720 °F
Melting Onset (Solidus)
840 °C 1550 °F
Specific Heat Capacity
350 J/kg-K 0.083 BTU/lb-°F
Thermal Conductivity
49 W/m-K 28 BTU/h-ft-°F
Thermal Expansion
19 µm/m-K
Electrical Properties
Electrical Conductivity: Equal Volume
11 % IACS
Electrical Conductivity: Equal Weight (Specific)
11 % IACS
Otherwise Unclassified Properties
Base Metal Price
31 % relative
Density
9.0 g/cm3 560 lb/ft3
Embodied Carbon
3.2 kg CO2/kg material
Embodied Energy
51 MJ/kg 22 x 103 BTU/lb
Embodied Water
370 L/kg 44 gal/lb
Common Calculations
Resilience: Ultimate (Unit Rupture Work)
31 MJ/m3
Resilience: Unit (Modulus of Resilience)
98 kJ/m3
Stiffness to Weight: Axial
6.1 points
Stiffness to Weight: Bending
17 points
Strength to Weight: Axial
7.9 points
Strength to Weight: Bending
9.9 points
Thermal Diffusivity
16 mm2/s
Thermal Shock Resistance
9.8 points
Alloy Composition
Among cast copper alloys, the composition of C93600 bronze is notable for containing a comparatively high amount of lead (Pb). Lead is used to improve machinability and bearing properties, at the cost of toxicity. It also adds pressure tightness to castings.
| Cu | 79 to 83 | |
| Pb | 11 to 13 | |
| Sn | 6.0 to 8.0 | |
| P | 0 to 1.5 | |
| Ni | 0 to 1.0 | |
| Zn | 0 to 1.0 | |
| Sb | 0 to 0.55 | |
| Fe | 0 to 0.2 | |
| S | 0 to 0.080 | |
| 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
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