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EN CC494K (CuSn5Pb9-C) Leaded Tin Bronze

CC494K bronze is a bronze formulated for casting. Cited properties are appropriate for the as-fabricated (no temper or treatment) condition. CC494K is the EN numeric designation for this material. CuSn5Pb9-C is the EN chemical designation.

It has a very high electrical conductivity among cast bronzes. In addition, it has a fairly low tensile strength and a fairly low ductility.

The graph bars on the material properties cards below compare CC494K 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

Brinell Hardness


Elastic (Young's, Tensile) Modulus

100 GPa 15 x 106 psi

Elongation at Break

7.6 %

Poisson's Ratio


Shear Modulus

39 GPa 5.6 x 106 psi

Tensile Strength: Ultimate (UTS)

210 MPa 31 x 103 psi

Tensile Strength: Yield (Proof)

94 MPa 14 x 103 psi

Thermal Properties

Latent Heat of Fusion

180 J/g

Maximum Temperature: Mechanical

160 °C 320 °F

Melting Completion (Liquidus)

970 °C 1770 °F

Melting Onset (Solidus)

890 °C 1640 °F

Specific Heat Capacity

360 J/kg-K 0.085 BTU/lb-°F

Thermal Conductivity

63 W/m-K 36 BTU/h-ft-°F

Thermal Expansion

19 µm/m-K

Electrical Properties

Electrical Conductivity: Equal Volume

16 % IACS

Electrical Conductivity: Equal Weight (Specific)

16 % IACS

Otherwise Unclassified Properties

Base Metal Price

31 % relative


9.1 g/cm3 570 lb/ft3

Embodied Carbon

3.1 kg CO2/kg material

Embodied Energy

50 MJ/kg 21 x 103 BTU/lb

Embodied Water

360 L/kg 43 gal/lb

Common Calculations

Resilience: Ultimate (Unit Rupture Work)

13 MJ/m3

Resilience: Unit (Modulus of Resilience)

43 kJ/m3

Stiffness to Weight: Axial

6.4 points

Stiffness to Weight: Bending

17 points

Strength to Weight: Axial

6.5 points

Strength to Weight: Bending

8.8 points

Thermal Diffusivity

19 mm2/s

Thermal Shock Resistance

7.8 points

Alloy Composition

Among cast copper alloys, the composition of CC494K 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.

Copper (Cu)Cu 78 to 87
Lead (Pb)Pb 8.0 to 10
Tin (Sn)Sn 4.0 to 6.0
Nickel (Ni)Ni 0 to 2.0
Zinc (Zn)Zn 0 to 2.0
Antimony (Sb)Sb 0 to 0.5
Iron (Fe)Fe 0 to 0.25
Manganese (Mn)Mn 0 to 0.2
Phosphorus (P)P 0 to 0.1
Sulfur (S)S 0 to 0.1
Silicon (Si)Si 0 to 0.010
Aluminum (Al)Al 0 to 0.010

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

Followup Questions

Similar Alloys

Further Reading

EN 1982: Copper and copper alloys - Ingots and castings