IS 291 II

IS 291 Grade II naval brass is a high-quality brass alloy used extensively in marine and industrial applications for its excellent strength, corrosion resistance, and machinability. It provides good creep resistance and high impact strength with excellent electrical and thermal conductivity.

Chemical Composition

• Copper (Cu): 59.00 – 62.00%

• Lead (Pb): 0.50 – 1.00%

• Tin (Sn): 0.50 – 1.00%

• Iron (Fe): Up to 0.10%

• Zinc (Zn): Remainder

• Total Others: Up to 0.20%

Mechanical Properties

• Tensile Strength: Approximately 390 MPa (varies with size and shape)

• Minimum Elongation: 15%

• Hardness: Not explicitly specified; typical naval brass hardness ranges

Physical Properties

• Melting Point: Solidus ~1630°F (888°C), Liquidus ~1650°F (899°C)

• Density: 8.44 g/cm³

• Electrical Conductivity: 26% IACS at 68°F

• Thermal Conductivity: 67 BTU/(ft²·hr·°F)

• Coefficient of Thermal Expansion: 11.8 × 10⁻⁶ per °F

• Specific Heat Capacity: 0.09 BTU/lb/°F

• Modulus of Elasticity: 15,000 ksi

• Modulus of Rigidity: 5,600 ksi

Fabrication and Applications

• Excellent soldering capability, good brazing

• Not recommended for oxyacetylene or arc welding; limited suitability for butt welding

• Poor cold workability but good hot workability (forgeability rating 90)

• Machinability rating is approximately 70%

• Commonly used in marine hardware, fasteners, valve stems, pump parts, and other precision machined components