CC491K

CC491K is a leaded gunmetal bronze alloy, also known by names such as LG2 and CuSn5Zn5Pb5-C. It is a copper-tin-lead-zinc alloy offering good machinability, moderate strength, and excellent wear and corrosion resistance.

Chemical Composition

• Copper (Cu): 83.0 – 87.0%

• Tin (Sn): 4.0 – 6.0%

• Lead (Pb): 4.0 – 6.0%

• Zinc (Zn): 4.0 – 6.0%

• Nickel (Ni): Up to 2.0%

• Phosphorus (P): Max 0.01%

• Minor amounts of iron, sulfur, antimony, and silicon

Mechanical Properties

• Tensile Strength: Approximately 230 MPa (minimum)

• Yield Strength (0.2% proof): Approximately 110 MPa (minimum)

• Elongation: About 10 – 13%

• Hardness: Around 65 HB (Brinell Hardness)

Physical Properties

• Density: About 8.8 g/cm³

• Melting Point: Approximately 1010°C

• Thermal Conductivity: ~72 W/m·K

• Thermal Expansion Coefficient: 18 x 10⁻⁶ /°C

• Modulus of Elasticity: About 93 GPa

Key Features and Applications

• Excellent machinability and wear resistance

• Good corrosion resistance, including resistance to dezincification

• Used commonly for pump and valve components, bearings under light loads, gears, architectural trims, and general engineering parts

• Suitable for continuous, centrifugal, and sand casting methods