A Nickel-Iron, controlled expansion alloy containing 48% Nickel. Its coefficient of thermal expansion was designed to match that of soft lead and soda-lime glasses. This alloy also has a high inflection point.
Nilo® 48 is also known as Invar 48 and Magnifer 50.
| Element | Min % | Max % |
| Ni | 48.00 nominal | |
| Fe | bal | |
| Mn | – | 0.80 |
| Si | – | 0.30 |
| C | – | 0.05 |
| Cr | – | 0.25 |
| P | – | 0.025 |
| S | – | 0.03 |
| Al | – | 0.10 |
Density
8.2 g/cm³ | 0.296 lb/in³
Melting Point
1450°C | 2640°F
Coefficient of Expansion
460°C | 860°F
Modulus of Rigidity
16.7 W/m•°C | 116 btu•in/ft2•h°F
Modulus of Elasticity
8.5 µm/m °C (20 – 100°C) 8.3 – 9.3 µm/m °C (20 – 300°C) | 4.7 x 10-6 in/in °F (70 – 212°F) 4.6 – 5.2 x 10-6 in/in °F (70 – 572°F)
Heat Treatment of Finished Parts
| Type | Temperature | Time (Hr) | Cooling | |
| °C | °F | |||
| Anneal | 850 – 1000 | 1560 – 1830 | 0.5 | Air or water |
Properties
| Condition | Approx. tensile strength | Approx. operating temperature | ||
| N/mm² | ksi | °C | °F | |
| Annealed | 450 – 550 | 65 – 80 | up to +450 | up to +840 |
| Hard Drawn | 700 – 900 | 102 – 131 | up to +450 | up to +840 |