CW621N
CW621N is a lead-free material that is well-suited for machining due to its structural composition. It can serve as a cost-effective alternative to traditional lead-containing machining brass, as long as it doesn’t need to meet stringent mechanical property and corrosion resistance requirements.
CHEMICAL COMPOSITION
| Elements | Min (%) | Max (%) |
| Cu | 55.50 | 59.00 |
| Pb | 0.20 | 0.80 |
| Sn | – | 0.30 |
| Fe | – | 0.30 |
| Al | 0.05 | 0.50 |
| Ni | 0.30 | 0.30 |
| Total Others | – | 0.20 |
| Zn | Remainder | |
MECHANICAL PROPERTIES ACCORDING TO BS2874 (AS PER TEMPER M)
No Mechanical properties for this alloy. Mechanical properties as agreed between punchers and supplier.
| PHYSICAL PROPERTIES | |
| Electrical conductivity %IACS | 31 |
| Thermal conductivity W/(m·K) | 139 |
| Thermal expansion coefficient (0–300 °C) | 10-6 /K 21.70 |
| Density | 8.41 g/cm3 |
| Modulus of elasticity | 107 Gpa |
| FABRICATION PROPERTIES | |
| Machinability (CuZn39Pb3 = 100 %) | 60% |
| Capacity for being cold worked | Poor |
| Capacity for being hot worked | Excellent |
| Resistance welding (butt weld) | Good |
| Inert gas shielded arc welding | Fair |
| Gas welding | Fair |
| Hard soldering | Good |
| Soft soldering | Excellent |
| Melting range | 870–900 °C |
| Hot working | 650–750 °C |
| Soft annealing (1–3 h) | 450–550 °C |
| Thermal stress relieving (1–3 h) | 250–350 °C |
