CZ128
CZ128 constitutes a machining brass that adeptly harmonizes the divergent material characteristics of machining and cold working. As a result, this material has firmly established itself as the prevailing standard alloy for machining and cold working applications across a multitude of industries.
CHEMICAL COMPOSITION
| Elements | Min (%) | Max (%) |
| Cu | 58.50 | 61.00 |
| Pb | 1.50 | 2.50 |
| Fe | – | 0.20 |
| Total Others | – | 0.50 |
| Zn | Remainder | |
MECHANICAL PROPERTIES ACCORDING TO BS2874 (AS PER TEMPER M)
| Range (mm) | From | To | UTS Min (N/mm²) | PS Min | Elongation Min (%) | Hardness Min | Hardness Max | |
| Round (Dia) | 6 | 18 | 380 | – | 22 | – | – | |
| 18 | 40 | 380 | – | 22 | – | – | ||
| 40 | 75 | 350 | – | 25 | – | – | ||
| Hex (A/F) | 6 | 18 | 380 | – | 22 | – | – | |
| 18 | 40 | 380 | – | 22 | – | – | ||
| 40 | 70 | 350 | – | 25 | – | – | ||
| Square (A/F) | 6 | 18 | 380 | – | 22 | – | – | |
| 18 | 40 | 380 | – | 22 | – | – | ||
| 40 | 60 | 350 | – | 25 | – | – | ||
| Rectangle (Thickness) | 6 | 18 | 380 | – | 22 | – | – | |
| 18 | 40 | 380 | – | 22 | – | – | ||
| 40 | 50 | 350 | – | 25 | – | – | ||
| PHYSICAL PROPERTIES | |
| Density | 8.44 g/cm³ |
| Electrical Conductivity % IACS at 68°F | 24 |
| Thermal Conductivity Btu/ sq ft/ ft hr/ °F at 68°F | 109 W/m.K |
| Thermal expansion coefficient | 20.4 10-6/K |
| Modulus of Elasticity | 102 Gpa |
| FABRICATION PROPERTIES | |
| Machinability (CuZn39Pb3 = 100 %) | 90% |
| Capacity for being cold worked | fair |
| Capacity for being hot worked | excellent |
| Resistance welding (butt weld) | good |
| Inert gas shielded arc welding | poor |
| Gas welding | Poor |
| Hard soldering | fair |
| Soft soldering | excellent |
| Melting range | 895-900 °C |
| Hot working | 650-750 °C |
| Soft annealing | 450-650 °C (1–3 hr) |
| Thermal stress relieving | 200-300 °C (1-3 hr) |
