C90300

C90300 is a tin bronze alloy (sometimes called "modified Navy G"), specified in ASTM B505 for castings. It is known for its high strength, excellent corrosion resistance, and good wear properties.

Chemical Composition

• Copper (Cu): 86.0 – 89.0%

• Tin (Sn): 7.5 – 9.0%

• Zinc (Zn): 3.0 – 5.0%

• Lead (Pb): max 0.30%

• Iron (Fe): max 0.20%

• Nickel (Ni + Co): max 1.00%

• Phosphorus (P): max 1.50%

• Antimony (Sb): max 0.20%

• Sulphur (S): max 0.05%

• Silicon (Si): max 0.005%

• Aluminium (Al): max 0.005%

Mechanical Properties (Typical for castings)

• Tensile Strength: min 303 MPa (44 ksi)

• Yield Strength: min 152 MPa (22 ksi)

• Elongation: min 18%

• Hardness: Brinell ~70

Physical Properties

• Density: 8.8 g/cm³

• Melting Range: 854–1000°C (solidus-liquidus)

• Electrical Conductivity: 12% IACS

• Thermal Conductivity: 43.2 Btu/sq ft/ft hr/°F at 68°F (75 W/m·K at 20°C)

• Modulus of Elasticity: 14000 ksi (96,000 MPa)

• Coefficient of Thermal Expansion: 17.3 x 10⁻⁶ /°C

Applications

• Bearings & bushings

• Gears, seal rings, piston rings

• Pump impellers, valve bodies, and steam fittings

• Plumbing and potable water applications (lead-free variants)

• Marine and high-load mechanical components