IS 319 III

IS 319 Grade III is a ductile leaded free-cutting brass alloy with good machinability, bending, and cold heading properties. It is especially suitable for applications like bicycle spoke nipples and precision components.

The chemical composition ranges as follows:

• Copper (Cu): 62.00 to 63.00%

• Lead (Pb): 0.50 to 1.50%

• Iron (Fe): Up to 0.20%

• Zinc (Zn): Balance

• Other impurities: Up to 0.50%

Mechanical properties vary by bar diameter:

• Diameter 6 to 12 mm: Tensile Strength minimum 355 MPa, Elongation minimum 8%

• Diameter 12 to 25 mm: Tensile Strength minimum 345 MPa, Elongation minimum 12%

• Diameter 25 to 50 mm: Tensile Strength minimum 305 MPa, Elongation minimum 22%

• Diameter 50 to 75 mm: Tensile Strength minimum 285 MPa, Elongation minimum 27%

Physical properties include a density of 8.46 g/cm³, melting point around 910°C, specific heat capacity of 0.377 kJ/kg·K, electrical conductivity 14.7 MS/m, modulus of elasticity 105 GPa, thermal conductivity 116 W/m·K, and coefficient of thermal expansion 20.4 x 10⁻⁶ /K.

Fabrication properties:

• Machinability rated at about 80% relative to CuZn39Pb3

• Poor cold working capacity

• Fair hot working capacity

• Excellent suitability for soldering

• Good suitability for brazing