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Re: copper magnet wire
Gauges are sort of arbitrary... Originally, the difference between sizes
was the amount the wire was drawn down in each pass through a die. For
mechanical reasons, this leads to a progression where the ratio of
diameters between successive gauges is constant (i.e. each gauge is some
percentage of the next bigger size). There were variations, though,
depending on drawing technique, the metal being drawn, etc. About a 100
years ago, they standardized on a strict geometric progression, starting
with AWG 10 and AWG 40, and dividing it up into even geometric steps, and
then extending either side of that range using the same ratio.
As a practical matter, too, the standard only calls for limited precision,
so depending on whose wire you are buying, what lot it came from, etc. it
can vary by several percent. To be cynical, I would suspect that when
copper prices rise, the measured diameter for a given gauge will shrink..
Just a bit more speed on the drawing machine and you get a few more feet
per ton of copper. By the by, some automated drawing machines actually use
the resistance to determine the gauge and hence to automatically adjust the
drawing speed through the die.
Sheet metal gauges are totally different, and based on the number of square
feet you get from a pound of metal. Shotgun gauges are based on the number
of lead balls you can make from a pound of lead.
The gauge scheme depends on the original manufacturing technique, hammering
a lump flat (sheet metal), casting a lump (ball ammo), or drawing through
a die (wire)...
Personally, I wish we'd all go to metric style gauges where it is rated by
the cross sectional area. The whole "circular mil" scheme for wire always
drives me batty.

> From: Tesla List <teslaatpupmandotcom>
> To: teslaatpupmandotcom
> Subject: Re: copper magnet wire
> Date: Wednesday, August 25, 1999 10:49 AM
>
> Original Poster: "Bill Noble" <william_b_nobleatemail.msndotcom>
>
> 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 <teslaatpupmandotcom>
> To: <teslaatpupmandotcom>
> Sent: Monday, August 23, 1999 4:34 PM
> Subject: Re: copper magnet wire
>
>
> > Original Poster: "Choad" <choad69atgeocitiesdotcom>
> >
> > 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_nobleatemail.msndotcom>
> > <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.)
> >
> >
> >
>
>
>
>
>
>