IS 291 I

IS 291 Grade I (Naval Brass Grade I) is a naval brass alloy commonly used for marine and subsea applications due to its superior strength and corrosion resistance. It also retains good mechanical properties at cryogenic temperatures and shows excellent hot formability.

Chemical Composition

• Copper (Cu): 61.00 – 64.00%

• Tin (Sn): 1.00 – 1.50%

• Lead (Pb): Up to 0.20%

• Iron (Fe): Up to 0.10%

• Zinc (Zn): Remainder

• Total others: Up to 0.20%

Mechanical Properties

• Tensile Strength (UTS): Approximately 345 – 390 MPa depending on diameter

• Minimum Elongation: 18%

• Hardness (HRB): Not explicitly specified

Physical Properties

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

• Density: 8.41 g/cm³

• Electrical Conductivity: 26% IACS

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

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

• Modulus of Elasticity: 15,000 ksi

• Modulus of Rigidity: 5,600 ksi

Fabrication and Uses

• Excellent hot workability (forgeability rating 90%)

• Fair cold workability

• Machinability rating is approximately 30%

• Excellent soldering and brazing properties

• Good oxyacetylene welding

• Used in marine hardware, valve components, pump parts, and subsea equipment