UNS C31600 Nickel-Bearing Leaded Hardware Bronze
C31600 bronze is a bronze formulated for primary forming into wrought products. It can have a moderately low tensile strength among wrought bronzes. In addition, it has a moderately high electrical conductivity and a moderately high thermal conductivity.
The properties of C31600 bronze include three 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 C31600 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
Elongation at Break
6.7 to 28 %
Poisson's Ratio
0.33
Shear Modulus
42 GPa 6.1 x 106 psi
Shear Strength
170 to 270 MPa 25 to 39 x 103 psi
Tensile Strength: Ultimate (UTS)
270 to 460 MPa 39 to 67 x 103 psi
Tensile Strength: Yield (Proof)
80 to 390 MPa 12 to 57 x 103 psi
Thermal Properties
Latent Heat of Fusion
200 J/g
Maximum Temperature: Mechanical
180 °C 360 °F
Melting Completion (Liquidus)
1040 °C 1900 °F
Melting Onset (Solidus)
1010 °C 1850 °F
Specific Heat Capacity
380 J/kg-K 0.091 BTU/lb-°F
Thermal Conductivity
140 W/m-K 81 BTU/h-ft-°F
Thermal Expansion
18 µm/m-K
Electrical Properties
Electrical Conductivity: Equal Volume
32 % IACS
Electrical Conductivity: Equal Weight (Specific)
33 % IACS
Otherwise Unclassified Properties
Base Metal Price
29 % relative
Density
8.8 g/cm3 550 lb/ft3
Embodied Carbon
2.7 kg CO2/kg material
Embodied Energy
43 MJ/kg 18 x 103 BTU/lb
Embodied Water
310 L/kg 37 gal/lb
Common Calculations
Resilience: Ultimate (Unit Rupture Work)
30 to 58 MJ/m3
Resilience: Unit (Modulus of Resilience)
28 to 690 kJ/m3
Stiffness to Weight: Axial
7.1 points
Stiffness to Weight: Bending
18 points
Strength to Weight: Axial
8.5 to 15 points
Strength to Weight: Bending
11 to 15 points
Thermal Diffusivity
42 mm2/s
Thermal Shock Resistance
9.4 to 16 points
Alloy Composition
Among wrought copper alloys, the composition of C31600 bronze is notable for including phosphorus (P) and containing a comparatively high amount of lead (Pb). Phosphorus is used as an alloy deoxidizer, and to reduce vulnerability to dezincification. Lead is used to improve machinability and bearing properties, at the cost of toxicity.
| Cu | 87.5 to 90.5 | |
| Zn | 5.2 to 10.5 | |
| Pb | 1.3 to 2.5 | |
| Ni | 0.7 to 1.2 | |
| P | 0.040 to 0.1 | |
| Fe | 0 to 0.1 | |
| res. | 0 to 0.4 |
All values are % weight. Ranges represent what is permitted under applicable standards.
Followup Questions
Similar Alloys
Further Reading
ASTM B140: Standard Specification for Copper-Zinc-Lead (Red Brass or Hardware Bronze) Rod, Bar, and Shapes
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