Brass C3604 (HPb59-1)

Brass C3604, also known as free-cutting brass or HPb59-1 in Chinese standards, is a leaded brass alloy renowned for its exceptional machinability. With approximately 59% copper and 1.5–2.5% lead content, it delivers outstanding chip-breaking performance and smooth surface finishes during CNC machining operations. It is one of the most widely used brass grades for precision turned parts, fasteners, and components requiring high-volume production efficiency.

Mechanical Properties

• Density: 8.50 g/cm³
• Tensile Strength: 370 MPa
• Yield Strength: 200 MPa
• Elongation at Break: 15%
• Hardness: HB 80–145
• Modulus of Elasticity: 100 GPa
• Thermal Conductivity: 115 W/m·K
• Electrical Conductivity: 26 % IACS
• Melting Point: 880–900 °C
• Coefficient of Thermal Expansion: 20.5 ×10⁻⁶ /°C

Advantages

✅ Exceptional Machinability — Rated as the easiest-to-machine brass alloy; produces clean chips and excellent surface finish without built-up edge (BUE)

✅ High Production Efficiency — Ideal for high-speed automated turning and screw machine operations; reduces machining cycle times significantly

✅ Good Corrosion Resistance — Performs well in atmospheric, freshwater, and mildly corrosive environments

✅ Cost-Effective — Lower material cost compared to other brass alloys while delivering reliable mechanical properties for general-purpose applications

Machining & Manufacturing

Common Applications