C69400 

C69400 is a silicon red brass alloy, characterised by its high copper content (80-83%) and silicon content (3.5-4.5%), along with zinc (11.5-16.5%) and trace amounts of lead, iron, and other impurities.

Chemical Composition

• Copper (Cu): 80.0% – 83.0%

• Silicon (Si): 3.5% – 4.5%

• Zinc (Zn): 11.5% – 16.5%

• Lead (Pb): Up to 0.3%

• Iron (Fe): Up to 0.2%

• Other impurities: Up to 0.5%

Mechanical Properties (Typical)

• Tensile Strength: Approx. 450 - 570 MPa (65 - 83 ksi)

• Yield Strength (0.5% offset): Approx. 240 - 270 MPa (35 - 40 ksi)

• Elongation: Around 15% minimum

• Rockwell B Hardness: Approx. 35 - 40

• Modulus of Elasticity: Approx. 110 GPa (16 million psi)

Physical Properties

• Density: Approx. 8.19 g/cm³

• Melting Point: Solidus ~1510°F (821°C), Liquidus ~1685°F (918°C)

• Electrical Conductivity: 6.2% IACS

• Thermal Conductivity: Approx. 15 BTU/sq ft/ft/hr/°F (25.98 W/m·K)

• Thermal Expansion Coefficient: 11.2×10−6/°F

Fabrication and Uses

• Excellent for soldering, brazing, oxyacetylene welding, spot welding, seam welding, and butt welding

• Poor capacity for cold work, but excellent hot forming ability

• Machinability rating approx. 30%

• Typical applications include valve stems, automotive and industrial parts, pipe fittings, and components exposed to corrosive environments where strength and corrosion resistance are critical