NiChrome Wire is the optimal wire choice for foam cutters for a variety of reasons, but particularly because it is resistant against corrosion and oxidation at very high temperature.
There are two readily available types of wire, NiChrome A & NiChrome C
- Nichrome A contains 80% Nickel and 20% Chromium
- Nichrome C contains 60% Nickel, 16% Chromium, & 24% Iron
By comparison, there isn’t too much different between the two wires with the exception of the following
- Nichrome C has a little higher resistance per foot
- Nichrome C increases more resistance per foot as temperature increases
- Nichrome A has higher tensile strength
- Nichrome A has a higher melting point
Based on this information it would appear that NiChrome A is better to use, but as it stands NiChrome C is a bit easier to acquire and a bit cheaper. But practically speaking, there is not much functional difference between the two when it comes to cutting foam.
Approximate amperage you will need to heat a straight oxidized wire in air to the specified temperature.
Temperature °F |
400 | 600 | 800 | 1000 | 1200 | 1400 | 1600 | 1800 | 2000 | |
Temperature °C |
205 | 315 | 427 | 538 | 649 | 760 | 871 | 982 | 1093 | |
gauge | Dia (in) | Amperes | ||||||||
14 | .0641 | 8.4 | 11.6 | 15 | 18.8 | 23.5 | 29 | 34.6 | 40.5 | 46 |
15 | .0571 | 7.2 | 10 | 12.8 | 16.1 | 20 | 24.5 | 29.4 | 34.3 | 39.2 |
16 | .05108 | 6.4 | 8.7 | 10.9 | 13.7 | 17 | 20.9 | 25.1 | 29.4 | 33.6 |
17 | .0453 | 5.5 | 7.5 | 9.5 | 11.7 | 14.5 | 17.6 | 21.1 | 24.6 | 28.1 |
18 | .0403 | 4.8 | 6.5 | 8.2 | 10.1 | 12.2 | 14.8 | 17.7 | 20.7 | 23.7 |
19 | .0359 | 4.3 | 5.8 | 7.2 | 8.7 | 10.6 | 12.7 | 15.2 | 17.8 | 20.5 |
20 | .0320 | 3.8 | 5.1 | 6.3 | 7.6 | 9.1 | 11 | 13 | 15.2 | 17.5 |
22 | .0253 | 2.9 | 3.7 | 4.5 | 5.6 | 6.8 | 8.2 | 9.6 | 11.0 | 12.5 |
24 | .0201 | 2.2 | 2.9 | 3.4 | 4.2 | 5.1 | 6.0 | 7.1 | 8.2 | 9.4 |
26 | .0159 | 1.7 | 2.1 | 2.6 | 3.2 | 3.8 | 4.5 | 5.3 | 6.1 | 6.9 |
28 | .0126 | 1.2 | 1.6 | 2.0 | 2.4 | 2.9 | 3.4 | 3.9 | 4.5 | 5.1 |
30 | .0100 | .92 | 1.2 | 1.5 | 1.8 | 2.1 | 2.5 | 2.9 | 3.3 | 3.7 |
32 | .0080 | .68 | .90 | 1.1 | 1.4 | 1.6 | 1.9 | 2.2 | 2.5 | 2.8 |
34 | .0063 | .50 | .68 | .83 | 1.0 | 1.2 | 1.4 | 1.6 | 1.8 | 2.0 |
36 | .0050 | .38 | .52 | .63 | .77 | .89 | 1.0 | 1.2 | 1.3 | 1.5 |
38 | .0040 | .30 | .41 | .50 | .59 | .68 | .78 | .88 | .98 | 1.1 |
40 | .0031 | .24 | .31 | .36 | .43 | .50 | .57 | .64 | .72 | .79 |