Nichrome, a non-magnetic alloy of nickel and chromium, is commonly used to make resistance wire because it has a high resistivity and resistance to oxidation at high temperatures. When used as a heating element, resistance wire is usually wound into coils.
Constantan is used where resistance is required to not change with temperature. Constantan is readily solderable, though soldered joints have limited temperature range.
Many elements and alloys have been used as resistance wire for special purposes. The table below lists the resistivity of some common materials, with copper included as a comparison.
Material |
Resistance (ohm-cmil/ft) |
Resistance (ohm-cm) |
|---|---|---|
| Aluminum | 15.94 | 2.650 e-6 |
| Brass | 42.1 | 7.0 e-6 |
| Carbon (amorphous) | 3.8-4.1 e-6 | |
| Constantan | 272.97 | 45.38 e-6 |
| Copper | 10.09 | 1.678 e-6 |
| Iron | 57.81 | 9.61 e-6 |
| Manganin | 290 | 48.21 e-6 |
| Molybdenum | 32.12 | 5.34 e-6 |
| Nichrome | 675 | 112.2 e-6 |
| Nichrome V | 650 | 108.1 e-6 |
| Nickel | 41.69 | 6.93 e-6 |
| Platinum | 63.16 | 10.5 e-6 |
| Stainless steel (304) | 541 | 90 e-6 |
| Steel (0.5% carbon) | 100 | 16.62 e-6 |
| Tungsten | 31.76 | 5.28 e-6 |
| Zinc | 35.49 | 5.90 e-6 |