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UNS C16500 Cadmium-Tin Copper

C16500 copper is a lightly alloyed grade of copper, formulated for primary forming into wrought products. It has a moderately low melting temperature among the wrought coppers in the database.

The properties of C16500 copper include five 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 C16500 copper to: wrought coppers (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 17 x 106 psi

Elongation at Break

1.5 to 53 %

Poisson's Ratio


Rockwell Superficial 30T Hardness

67 to 73

Shear Modulus

43 GPa 6.2 x 106 psi

Shear Strength

200 to 310 MPa 29 to 45 x 103 psi

Tensile Strength: Ultimate (UTS)

280 to 530 MPa 40 to 77 x 103 psi

Tensile Strength: Yield (Proof)

97 to 520 MPa 14 to 75 x 103 psi

Thermal Properties

Latent Heat of Fusion

210 J/g

Maximum Temperature: Mechanical

340 °C 650 °F

Melting Completion (Liquidus)

1070 °C 1960 °F

Melting Onset (Solidus)

1010 °C 1850 °F

Specific Heat Capacity

380 J/kg-K 0.091 BTU/lb-°F

Thermal Conductivity

250 W/m-K 150 BTU/h-ft-°F

Thermal Expansion

17 µm/m-K

Electrical Properties

Electrical Conductivity: Equal Volume

60 % IACS

Electrical Conductivity: Equal Weight (Specific)

61 % IACS

Otherwise Unclassified Properties

Base Metal Price

31 % relative


8.9 g/cm3 560 lb/ft3

Embodied Carbon

2.6 kg CO2/kg material

Embodied Energy

42 MJ/kg 18 x 103 BTU/lb

Embodied Water

320 L/kg 38 gal/lb

Common Calculations

Resilience: Ultimate (Unit Rupture Work)

7.8 to 110 MJ/m3

Resilience: Unit (Modulus of Resilience)

41 to 1160 kJ/m3

Stiffness to Weight: Axial

7.1 points

Stiffness to Weight: Bending

18 points

Strength to Weight: Axial

8.6 to 17 points

Strength to Weight: Bending

11 to 16 points

Thermal Diffusivity

74 mm2/s

Thermal Shock Resistance

9.8 to 19 points

Alloy Composition

Among wrought copper alloys, the composition of C16500 copper is notable for including cadmium (Cd). Cadmium is used to improve strength at elevated temperatures.

Copper (Cu)Cu 97.8 to 98.9
Cadmium (Cd)Cd 0.6 to 1.0
Tin (Sn)Sn 0.5 to 0.7
Iron (Fe)Fe 0 to 0.020
Residualsres. 0 to 0.5

All values are % weight. Ranges represent what is permitted under applicable standards.

Followup Questions

Similar Alloys

Further Reading

Copper Alloys: Preparation, Properties and Applications, Michael Naboka and Jennifer Giordano (editors), 2013