CW718R
CW718 is a specialized brass alloy known for its moderate strength, remarkable resistance to atmospheric corrosion, and favorable sliding properties, thanks to the presence of manganese and aluminum as alloying elements. CW718R, a variant of this alloy, serves as a standard bearing material specifically designed for applications with medium-level loads within the realm of machine construction.
CHEMICAL COMPOSITION
| Elements | Min (%) | Max (%) |
| Cu | 57.00 | 59.00 |
| Pb | 0.20 | 0.80 |
| Al | 0.30 | 1.30 |
| Fe | – | 0.50 |
| Mn | 0.80 | 1.80 |
| Ni | – | 0.50 |
| Sn | – | 0.50 |
| Si | – | 0.50 |
| Total others | – | 0.30 |
| Zn | Remainder | |
MECHANICAL PROPERTIES ACCORDING TO EN12165 CW718 (AS PER TEMPER H130)
| Range (mm) | From | To | UTS Min (N/mm²) | PS Min (N/mm²) | Elongation Min (%) | Hardness Min (HB) | Hardness Max |
| Round (Dia) | 6 | 75 | – | – | – | 130 | – |
| Hex (A/F) | 6 | 70 | – | – | – | 130 | – |
| Square (A/F) | 6 | 60 | – | – | – | 130 | – |
| Rectangle (Thickness) | 6 | 50 | – | – | – | 130 | – |
| PHYSICAL PROPERTIES | |
| Electrical conductivity | 7.8 %IACS |
| Thermal conductivity | 63 W/(m•K) |
| Thermal expansion coefficient (0–300 °C) | 21.1 10-6/K |
| Density | 8.24 g/cm³ |
| Modulus of elasticity | 93 Gpa |
| FABRICATION PROPERTIES | |
| Machinability (CuZn39Pb3 = 100 %) | 40% |
| Capacity for being cold worked | Poor |
| Capacity for being hot worked | good |
| Resistance welding (butt weld) | good |
| Inert gas shielded arc welding | fair |
| Gas welding | Poor |
| Hard soldering | fair |
| Soft soldering | Poor |
| Melting range | 860-910 °C |
| Hot working | 600–700 °C |
| Soft annealing | 500–650 °C (1–3 hr) |
| Thermal stress relieving | 300–430 °C (1-3 hr) |
