UNS C93700 Leaded Tin Bronze
C93700 bronze is a bronze formulated for casting. Cited properties are appropriate for the as-fabricated (no temper or treatment) condition. C93700 is the UNS number for this material. Additionally, the common industry name is 80-10-10. Older literature may refer to this material as ASTM Alloy 3A, Alloy C, or SAE 64.
It has a very low melting temperature among cast bronzes. In addition, it has a fairly low heat capacity and a moderately low tensile strength.
The graph bars on the material properties cards below compare C93700 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
210 MPa 30 x 103 psi
Elastic (Young's, Tensile) Modulus
99 GPa 14 x 106 psi
Elongation at Break
20 %
Fatigue Strength
90 MPa 13 x 103 psi
Impact Strength: V-Notched Charpy
15 J 11 ft-lb
Poisson's Ratio
0.35
Rockwell B Hardness
60
Shear Modulus
37 GPa 5.3 x 106 psi
Tensile Strength: Ultimate (UTS)
240 MPa 35 x 103 psi
Tensile Strength: Yield (Proof)
130 MPa 18 x 103 psi
Thermal Properties
Latent Heat of Fusion
170 J/g
Maximum Temperature: Mechanical
140 °C 290 °F
Melting Completion (Liquidus)
930 °C 1710 °F
Melting Onset (Solidus)
760 °C 1400 °F
Solidification (Pattern Maker's) Shrinkage
1.1 %
Specific Heat Capacity
350 J/kg-K 0.083 BTU/lb-°F
Thermal Conductivity
47 W/m-K 27 BTU/h-ft-°F
Thermal Expansion
19 µm/m-K
Electrical Properties
Electrical Conductivity: Equal Volume
10 % IACS
Electrical Conductivity: Equal Weight (Specific)
10 % IACS
Otherwise Unclassified Properties
Base Metal Price
33 % relative
Density
8.9 g/cm3 560 lb/ft3
Embodied Carbon
3.5 kg CO2/kg material
Embodied Energy
57 MJ/kg 24 x 103 BTU/lb
Embodied Water
390 L/kg 47 gal/lb
Common Calculations
Resilience: Ultimate (Unit Rupture Work)
40 MJ/m3
Resilience: Unit (Modulus of Resilience)
79 kJ/m3
Stiffness to Weight: Axial
6.2 points
Stiffness to Weight: Bending
17 points
Strength to Weight: Axial
7.5 points
Strength to Weight: Bending
9.6 points
Thermal Diffusivity
15 mm2/s
Thermal Shock Resistance
9.4 points
Alloy Composition
Among cast copper alloys, the composition of C93700 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 | 78 to 82 | |
| Sn | 9.0 to 11 | |
| Pb | 8.0 to 11 | |
| P | 0 to 1.5 | |
| Ni | 0 to 1.0 | |
| Zn | 0 to 0.8 | |
| Sb | 0 to 0.5 | |
| Fe | 0 to 0.15 | |
| S | 0 to 0.080 | |
| Si | 0 to 0.0050 | |
| Al | 0 to 0.0050 | |
| res. | 0 to 1.0 |
All values are % weight. Ranges represent what is permitted under applicable standards.
Followup Questions
Similar Alloys
Further Reading
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