# Re: copper magnet wire

```yes, it looks like you are right, but I did read somewhere that it is in
fact the number of wires that fit through a ??? that determines the gauge.
According to a 1954 reprint of Audel's mathematics and calculations for
mechanics (that happens to be sitting here),  page 114, in a footnote: "
note - the sizes of wire are ordinarily expressed by an arbitrary series of
numbers.  unfortunately there are several independent numbering methods, so
that it is always necessary to specify the method or wire gauge used."

The table provided above the footnote lists "americal or brown and sharpe",
Birmingham or stubs, washburn & moen mfg co, worchester mass, Trenton iron
co, trenton NJ, gwprentiss, holyoke mass, old english from Brass mfrs list,
and british standard.   I wonder which one we use today?
your table matches "american".  For 0000 gague, the diameters for the above
standares are respectively: 0.46000, o.454, 0.393, .400, N/A, N/A, .400.

There is also a table for American gauge, showing that 0000 gauge is equal
to two 0, four 3 gauge, eight 6, 16 -9, 32 -12, 64 -15, 128 -18 and so on -
as
you can see, for every doubling of the number of wires the equivalent gauge
increases by 3  (like decibels)

I swear I read somewhere, sometime that there was a relationship of the type
I described, but for now, I can't find it.  maybe someone else on the list
has the definitive answer?  I even tried my bosh automotive handbook, and it
doesn't even use wire gauge, it refers to the diameter in mm (so no help
there for the origin of the measurement).  But I did learn that the word
gauge comes (according to the OED) from old french with a meaing of
performing a measurment.

And, I did manage to confirm that sieve sizes are the number of mesh per
inch (see page 2166 of the 23rd edition of the handbook of physics and
chemistry (1939).  (not that it's totally relevnt, but it is obscure and
interesting)
----- Original Message -----
From: Tesla List <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Monday, August 23, 1999 4:34 PM
Subject: Re: copper magnet wire

>
> Bill,
>     I don't think it's # of bare turns per inch. #1 is 0.2893" in diameter
> just a little shy of the 1" mark. I'm going to post a wire chart I have
> below for anyone that wants it. Best if you look at it with a fixed font
> then past it to notepad or something.
> > Original Poster: "Bill Noble" <william_b_noble-at-email.msn-dot-com>
> <snip>
> > Wire size is called the wire "gage" - smaller numbers mean bigger wire.
> If
> > I remember right, the wire's gage is the number of wires (without
> > insulation) that will fit in a square inch - so "1" wire has a 1 inch
> > diameter, 2 has a 1/sqrt(2) or about 3/4 inch diameter and so on.  There
> are
> > tables of these wire sizes in many reference books.
>
> Wire Table for AWG 0000 to 40, with diam in mils, circular mils,
> square microinches, ohms per foot, ft per lb, etc. mils = 0.001"
>
>                        Wire Table  ANNEALED COPPER (AWG)
>       AWG  DIA in  CIRC   SQUARE  OHM per LBS per FT per  FT per  OHM per
>       gauge mils   MILS   MICROIN 1000 ft 1000 ft  LB     OHM     LB
>
======================================================================
>       0000 460.0  211600  166200  0.04901 640.5   1.561   20400
0.00007652
>       000  409.6  167800  131800  0.06180 507.9   1.968   16180
0.0001217
>       00   364.8  133100  104500  0.07793 402.8   2.482   12830
0.0001935
>       0    324.9  105500  82890   0.09827 319.5   3.130   10180
0.0003076
>       1    289.3  83690   65730   0.1239  253.3   3.947   8070
0.0004891
>       2    257.6  66370   52130   0.1563  200.9   4.977   6400
0.0007778
>       3    229.4  52640   41340   0.1970  159.3   6.276   5075    0.001237
>       4    204.3  41740   32780   0.2485  126.4   7.914   4025    0.001966
>       5    181.9  33100   26000   0.3133  100.2   9.980   3192    0.003127
>       6    162.0  26250   20620   0.3951  79.46   12.58   2531    0.004972
>       7    144.3  20820   16350   0.4982  63.02   15.87   2007    0.007905
>       8    128.5  16510   12970   0.6282  49.98   20.01   1592    0.01257
>       9    114.4  13090   10280   0.7921  39.63   25.23   1262    0.01999
>       10   101.9  10380   8155    0.9989  31.43   31.82   1001    0.03178
>       11   90.74  8234    6467    1.260   24.92   40.12   794     0.05053
>       12   80.81  6530    5129    1.588   19.77   50.59   629.6   0.08035
>       13   71.96  5178    4067    2.003   15.68   63.80   499.3   0.1278
>       14   64.08  4107    3225    2.525   12.43   80.44   396.0   0.2032
>       15   57.07  3257    2558    3.184   9.858   101.4   314.0   0.3230
>       16   50.82  2583    2028    4.016   7.818   127.9   249.0   0.5136
>       17   45.26  2048    1609    5.064   6.200   161.3   197.5   0.8167
>       18   40.30  1624    1276    6.385   4.917   203.4   156.6   1.299
>       19   35.89  1288    1012    8.051   3.899   256.5   124.2   2.065
>       20   31.96  1022    802.3   10.15   3.092   323.4   98.50   3.283
>       21   28.46  810.1   636.3   12.80   2.452   407.8   78.11   5.221
>       22   25.35  642.4   504.6   16.14   1.945   514.2   61.95   8.301
>       23   22.57  509.5   400.2   20.36   1.542   648.4   49.13   13.20
>       24   20.10  404.0   317.3   25.67   1.223   817.7   38.96   20.99
>       25   17.90  320.4   251.7   32.37   0.9699  1031.0  30.90   33.37
>       26   15.94  254.1   199.6   40.81   0.7692  1300    24.50   53.06
>       27   14.20  201.5   158.3   51.47   0.6100  1639    19.43   84.37
>       28   12.64  159.8   125.5   64.90   0.4837  2067    15.41   134.2
>       29   11.26  126.7   99.53   81.83   0.3836  2607    12.22   213.3
>       30   10.03  100.5   78.94   103.2   0.3042  3287    9.691   339.2
>       31   8.928  79.70   62.60   130.1   0.2413  4145    7.685   539.3
>       32   7.950  63.21   49.64   164.1   0.1913  5227    6.095   857.6
>       33   7.080  50.13   39.37   206.9   0.1517  6591    4.833   1364
>       34   6.305  39.75   31.22   260.9   0.1203  8310    3.833   2168
>       35   5.615  31.52   24.76   329.0   0.09542 10480   3.040   3448
>       36   5.000  25.00   19.64   414.8   0.07568 13210   2.411   5482
>       37   4.453  19.83   15.57   523.1   0.06001 16660   1.912   8717
>       38   3.965  15.72   12.35   659.6   0.04759 21010   1.516   13860
>       39   3.531  12.47   9.793   831.8   0.03774 26500   1.202   22040
>       40   3.145  9.888   7.766   1049.0  0.02993 33410   0.9534  35040
>
>   Ohms per 1000ft, ft per Ohm, Ohms per Lb all taken at 20 deg. C (68 deg.
> F.)
>
>
>

```