CZ129

CZ129, also known as CW611N, is a low leaded 60/40 brass alloy similar to Muntz Metal but with a fine dispersion of lead particles that enhances machinability. It offers excellent hot working properties, very good cold formability, and machinability, making it an ideal bending brass.

Chemical Composition

• Copper (Cu): 58.5 – 61.0%

• Lead (Pb): 0.8 – 1.6%

• Nickel (Ni): Max 0.3%

• Iron (Fe): Max 0.2%

• Aluminum (Al): Max 0.05%

• Tin (Sn): Max 0.2%

• Zinc (Zn): Balance

• Total Other Elements: Max 0.2%

Mechanical Properties

• Tensile Strength: Typically 380 MPa for smaller diameters, decreasing slightly for larger sizes

• Elongation: 25–28%

• Hardness: Not explicitly stated, but generally moderate

• Density: 8.41 g/cm³

• Melting Point: Around 920°C (liquidus)

Physical Properties

• Thermal Conductivity: ~121 W/m·K

• Thermal Expansion Coefficient (20–200°C): 20.9 x 10⁻⁶ /°C

• Electrical Conductivity: ~26% IACS

• Young’s Modulus: About 97 GPa

Fabrication Properties

• Excellent hot formability (650–750ºC)

• Good cold formability

• Machinability rating is approximately 60% relative to free cutting brass

• Soldering: Excellent

• Brazing: Good

• Welding: Typically not recommended

Applications

• Hot stampings

• Forged components

• Automotive and electrical parts

• Architectural and decorative hardware

• Components requiring bending and machining