C69430

C69430 is a silicon red brass alloy, typically containing about 80-83% copper with zinc as the balance, and silicon in the range of 3.5-4.5%. It is part of the silicon brass family, known for high strength, good corrosion resistance, and excellent retention of spring properties.

Chemical Composition

• Copper (Cu): 80.0% – 83.0%

• Silicon (Si): 3.5% – 4.5%

• Lead (Pb): Up to 0.30%

• Iron (Fe): Up to 0.20%

• Arsenic (As): Up to 0.06%

• Zinc (Zn): Balance

• Other impurities: Up to 0.50%

Mechanical Properties (Typical as per ASTM B371, temper H02)

• Tensile Strength: 65 – 80 ksi (450 – 550 MPa)

• Proof Stress: 35 – 40 ksi (240 – 275 MPa)

• Elongation: Minimum 15%

• Hardness (Rockwell B): 35 – 40

Physical Properties

• Melting Point (Solidus): 1510°F (821°C)

• Melting Point (Liquidus): 1685°F (918°C)

• Density: Approximately 8.19 g/cm³

• Electrical Conductivity: About 6.2% IACS at 68°F

• Thermal Conductivity: Around 15 Btu/sq ft/ft/hr/°F

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

• Modulus of Elasticity: Approximately 16,000 ksi

Fabrication and Uses

• Excellent soldering and brazing properties

• Good oxyacetylene welding and spot welding capabilities

• Suitable for cold working and excellent for hot forming (forgeability rating of 80)

• Machinability rating around 30%

• Commonly used for valve stems, automotive parts, industrial machinery, and pipe fittings