CZ137
CZ137, a variety of engraving brass, belongs to the 60/40 alpha-beta brass category and features the addition of lead to enhance its free machining properties. It’s important to note that CZ137 should not be employed for acid etching work; instead, the single-phase alpha brasses are recommended for such applications.
CHEMICAL COMPOSITION
| Elements | Min (%) | Max (%) |
| Cu | 55.50 | Pb |
| Pb | 0.30 | 0.80 |
| 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 | 40 | 380 | – | 25 | – | – |
| 40 | 350 | 350 | – | 28 | – | – | |
| Hex (A/F) | 6 | 40 | 380 | – | 25 | – | – |
| 40 | 75 | 350 | – | 28 | – | – | |
| Square (A/F) | 6 | 40 | 380 | – | 25 | – | – |
| 40 | 75 | 350 | – | 28 | – | – |
| PHYSICAL PROPERTIES | |
| Electrical conductivity %IACS | 31 |
| Thermal conductivity W/(m·K) | 139 |
| Thermal expansion coefficient (0–300 °C) | 10-6 /K 21.70 |
| 8.36 g/cm3 | 8.36 g/cm3 |
| Modulus of elasticity | 107 Gpa |
| FABRICATION PROPERTIES | |
| Machinability (CuZn39Pb3 = 100 %) | 50% |
| Capacity for being cold worked | poor |
| Capacity for being hot worked | Excellent |
| Resistance welding (butt weld) | Fair |
| Inert gas shielded arc welding | Fair |
| Gas welding | Fair |
| Hard soldering | Excellent |
| 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 |
