A Nickel-Iron, low expansion alloy containing 42% Nickel. It has a low and nominally constant coefficient of thermal expansion from room temperature to about 300oC (570oF).
Nilo® 42 is also known as Invar 42, Pernifer 40, Dilaton 42, and Glass Sealing 42.
| Element | Min % | Max % |
| Ni | 41.00 nominal | |
| Fe | bal | |
| Mn | – | 0.80 |
| Si | – | 0.30 |
| C | – | 0.05 |
| Cr | – | 0.25 |
| P | – | 0.03 |
| S | – | 0.03 |
| Al | – | 0.10 |
Density
8.11 g/cm³ | 0.293 lb/in³
Melting Point
1435°C | 2615°F
Coefficient of Expansion
370°C | 700°F
Modulus of Rigidity
10.5 W/m•°C | 72.8 btu•in/ft2•h°F
Modulus of Elasticity
5.3 µm/m °C (20 – 100°C) 4.5 – 6.5 µm/m °C (20 – 300°C) | 2.9 x 10-6 in/in °F (70 – 212°F) 2.5 – 3.6 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 +300 | up to +570 |
| Hard Drawn | 700 – 900 | 102 – 131 | up to +300 | up to +570 |