Nitinol vs Steel
Nitinol and Steel are genuine alternatives to one another — a choice somebody actually makes — and differ on 3 measured properties, density most clearly.
Nitinol vs Steel
Nitinol
Bend it and it remembers — a metal that returns to a shape it was taught, and the reason a stent can be threaded through an artery.
Steel
Iron with a controlled, small proportion of carbon — the most-used engineered material in the world.
| Property | Nitinol | Steel |
|---|---|---|
| Density | 6.4–6.5 g/cm³ | 7.75–8.05 g/cm³ higher |
| Electrical conductivity Only one of the two has a figure we can stand behind, so there is nothing to compare. | Not known | 6.99 MS/m |
| Melting point | 1240–1310 °C | 1370–1510 °C higher |
| Tensile strength | 800–1100 MPa | 400–2000 MPa higher |
| Thermal conductivity Only one of the two has a figure we can stand behind, so there is nothing to compare. | Not known | 15–54 W/(m·K) |
Choosing between them
Nitinol is recorded as a substitute for Steel — easier to work.
What it gives up: An order of magnitude more expensive, difficult to machine, and its behaviour depends on a transformation temperature that must be hit to a fraction of a per cent of composition.
In this application, on the evidence cited above.