Here is a wire chart originally done by Richard Quick. I have added info for additional wire sizes 41 AWG and over.
AWG Wire Chart
Approx. turns per
Inch, solid enamel
AWG D.C. OHMS Wire Diam Covered (single Feet Per
Size Per 1000 FT Inches Build) Pound
--------------------------------------------------------------------
1 .1264 .2893 X 3.947
2 .1593 .2576 X 4.977
3 .2009 .2294 X 6.276
4 .2533 .2043 X 7.914
5 .3195 .1819 X 9.980
6 .4028 .1620 X 12.58
7 .5080 .1443 X 15.87
8 .6405 .1286 7.6 20.01
9 .8077 .1144 8.6 25.23
10 1.018 .1019 9.6 31.82
11 1.284 .0907 10.7 40.12
12 1.619 .0808 12.0 50.59
13 2.042 .0720 13.5 63.80
14 2.524 .0641 15 80.44
15 3.181 .0571 16.8 101.40
16 4.018 .0508 18.9 127.90
17 5.054 .0453 21.2 161.3
18 6.386 .0403 23.6 203.4
19 8.046 .0359 26.4 256.5
20 10.13 .0320 29.4 323.4
21 12.77 .0285 33.1 407.8
22 16.20 .0253 37.0 514.2
23 20.30 .0226 41.3 648.4
24 25.67 .0201 46.3 817.7
25 32.37 .0179 51.7 1031
26 41.02 .0159 58.0 1300
27 51.44 .0142 64.9 1639
28 65.31 .0126 72.7 2067
29 81.21 .0113 81.6 2607
30 103.7 .0100 90.5 3287
31 130.9 .0089 101 4145
32 162.0 .0080 113 5227
33 205.7 .0071 127 6591
34 261.3 .0063 143 8310
35 330.7 .0056 158 10480
36 414.8 .0050 175 13210
37 512.1 .0045 198 16660
38 648.2 .0040 224 21010
39 846.6 .0036 248 26500
40 1079 .0031 282 33410
41 1323 .0028 323 40800
42 1659 .0025 357 50940
43 2143 .0022 400 66140
44 2593 .0020 455 80060
45 3348 .00176 521 103500
46 4207 .00157 578 130000
47 5291 .00140 633 163400
48 6745 .00124 714 204900
49 8417 .00111 806 259700
50 10580 .00099 885 324700
51 13390 .00088 971 406500
52 17050 .00078 1075 507600
53 21170 .00070 1266 653600
54 26980 .00062 1429 826400
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For winding Tesla secondary coils the general consensus is to use
number 22 AWG, or larger diameter, double Formvar Magnet wire. Often
surplus partial spools of odd wire sizes are found, so I took time to
post a more complete chart of AWG numbers and fractional diameters
than is usually available. All information above is approximate
despite the decimal places. Wire diameter, turns per inch, resistance,
feet per pound, etc. all vary slightly from one manufacturer to another.
Insulation thicknesses will vary depending upon type and the supplier.
Turns per inch will also vary with the quality of the winding. In
practice, Tesla coil windings are not perfect (nor do they need to be)
so expect some slight variations from the specification table above.
Richard Quick
.. If all else fails... Throw another megavolt across it!