wire specifications
Bernd Grubert
I have a rather simple question. In many parts lists I see wire specified by
numbers e.g. #20, #26 etc. I assume they refer solid copper wires. How do
they translate into diameters?
Thanks in advance
Bernd
Freeland
mils-.001inch
10
101.9
11
90.2
12
80.8
13
72.0
14
64.1
15
57.1
16
50.8
17
45.3
18
40.3
19
35.9
20
32.0
21
28.5
22
25.3
23
22.6
24
20.1
25
17.9
there are 40 listed, but I
figured you could use these.
73's from KD5FES.
Bernd Grubert wrote in message
<6ua7aa$l1k$1...@gorm.zfn.uni-bre
men.de>...
Wes Stewart N7WS
<bgru...@uni-bremen.de> wrote:
>Hello,
>
>I have a rather simple question. In many parts lists I see wire specified by
>numbers e.g. #20, #26 etc. I assume they refer solid copper wires. How do
>they translate into diameters?
>
>Thanks in advance
> Bernd
>
If the reference you are looking at is in the US, then the numbers
refer to AWG (American Wire Gage).
A fairly accurate conversion follows:
Diameter in inches = 10^(-0.05035 * AWG_number - 0.4884)
Diameter in millimeters = 10^(-0.05035 * AWG_number + 0.9164)
For guages larger than 0, use negative values, ie 000, use -2
Wes N7WS
Wes Stewart N7WS
Malcolm Huddart
from "Bernd Grubert" <bgru...@uni-bremen.de> contains these words:
> Hello,
> I have a rather simple question. In many parts lists I see wire specified by
> numbers e.g. #20, #26 etc. I assume they refer solid copper wires. How do
> they translate into diameters?
> Thanks in advance
> Bernd
The hash (#) stands for gauge. However, there are several standards,
SWG - Standard Wire Gauge, AWG - American Wire Gauge (use this one
for publications from USA) and BWG - Birmingham Wire Gauge.
Some standard examples are :-
Wire No. SWG AWG BWG
#10 3.25mm 2.59mm 3.40mm
#15 1.83mm 1.45mm 1.83mm
#20 0.92mm 0.81mm 0.89mm
#24 0.56mm 0.51mm 0.56mm
#26 0.46mm 0.40mm 0.46mm
#30 0.305mm 0.25mm 0.305mm
#35 0.203mm 0.14mm 0.127mm
Hope this helps,
Regards,
Malc G4OQR
Don W6JL
>
> Hello,
>
> I have a rather simple question. In many parts lists I see wire specified by
> numbers e.g. #20, #26 etc. I assume they refer solid copper wires. How do
> they translate into diameters?
>
> Thanks in advance
> Bernd
Bernd OM,
See any ARRL handbook, or engineering handbook in a library for
complete wire gauge tables. There are both British Wire Gauge and
American (U.S.) Wire Gauges (AWG), but most all references I find in ham
radio are for AWG.
73,
Don, W6JL
Joe Dubner
> If the reference you are looking at is in the US, then the numbers
> refer to AWG (American Wire Gage).
> A fairly accurate conversion follows:
> Diameter in inches = 10^(-0.05035 * AWG_number - 0.4884)
> Diameter in millimeters = 10^(-0.05035 * AWG_number + 0.9164)
> For guages larger than 0, use negative values, ie 000, use -2
A somewhat related and easy-to-remember rule of thumb: for every
increase in 3 wire gage sizes (i.e. #30 to #27), double the CMA
(circular mil area), weight (per unit length), and current capability.
Resistance (per unit length) will be halved.
If one can remember that #30 AWG has a CMA (circular mil area) of
approximately 100 (actually it's 101) and #10 AWG measures about 1 ohm
per 1000 feet and can handle 15A, one could construct a wire table from
scratch!
73,
Joe, K7JD
---------------------------------------------------------------------------
Joe Dubner K7JD | Hewlett-Packard Company | dub...@spk.HP.COM
| 24001 E. Mission Avenue |
| Liberty Lake, WA 99019 | +1 509 921-3514
---------------------------------------------------------------------------
Tom Bruhns
: Wes Stewart N7WS <n7...@azstarnet.com> wrote:
: > If the reference you are looking at is in the US, then the numbers
: > refer to AWG (American Wire Gage).
: > A fairly accurate conversion follows:
: > Diameter in inches = 10^(-0.05035 * AWG_number - 0.4884)
: > Diameter in millimeters = 10^(-0.05035 * AWG_number + 0.9164)
: > For guages larger than 0, use negative values, ie 000, use -2
: A somewhat related and easy-to-remember rule of thumb: for every
: increase in 3 wire gage sizes (i.e. #30 to #27), double the CMA
: (circular mil area), weight (per unit length), and current capability.
: Resistance (per unit length) will be halved.
: If one can remember that #30 AWG has a CMA (circular mil area) of
: approximately 100 (actually it's 101) and #10 AWG measures about 1 ohm
: per 1000 feet and can handle 15A, one could construct a wire table from
: scratch!
It was pointed out to me recently that this makes the AWG scale very
similar to a decibel scale: that is, if you think of the AWG number
as dB, and the diameter as "volts", you can use the db <--> volts
math you already (may) know to get from one gauge to another.
20 gauge-numbers gets you a 10:1 variation in diameter. Then resistance
and cross-sectional area are like "watts" on the dB scale. A bunch
of second-nature rules-of-thumb that I use all the time with dB
suddenly become available to work with wire gauges.
--
Cheers,
Tom
tom_b...@hp.com
Reg Edwards
The wire gauge system was invented in Birmingham, England, I think, around
1830. In those days Birmingham and the area just to the west was becoming
the world's centre of precision mechanical engineering, sometimes described
facetiously as "metal bashing". Electrical engineering had not been
thought of. Boulton and Watt's factory in Soho had to work to very close
limits in the manufacture of smooth-running steam engines to drive lift
cages and pumps in the coal mines, spinning gennies in the cotton mills and
machine tools in the new manufactories. Wire drawing requires precision
engineered machinery. The measuring gauges used by "quality control"
inspectors needed even greater precision to manufacture.
Iron, steel, brass, copper wires were begining to be used in great
quantities in many different kinds of manufactured products. Silver wire
was (and still is) used in the manufacture of jewellery. "Made in
Birmingham" appeared on the packaging of manufactured goods world-wide,
from pins, buttons, medals and coins, to kettles, steam hammers and other
giant machines used in industry.
The most expensive part in a wire drawing machine is the "die" which
contains the hole through which the wire is drawn. The finer wires are
obtained by drawing through successively smaller dies. But the amount of
reduction at each successive stage is limited. So adjacent wire diameters
all have the same relationship to each other. Even from the wire-user's
point of view it was economically sensible to restrict the number of
diameters available for sale. As engineers in those days were just as
familiar with log tables and exponentials as we are, and wire sizes
increase/decrease exponentially in a natural manner due to manufacturing
economics, what better method of standardisation is there than one based on
logs to the base 10. As you say Tom - just like decibels.
The North Americans of course, in Cincinatti, Pittsburg and Detroit, when
they eventually got around to drawing their own wire, some of it for
electrical purposes, and Birmingham, Alabama was not (then) an engineering
city, could not possibly use a system "not invented here" and felt obliged
to change the constants in the mathematical formula. Also the name.
So BWG became AWG.
A more convenient formula is -
Diameter = 0.3248 * 10^ ( - AWG / 20 ) inches, or
Diameter = 8.25 * 10^ ( - AWG / 20 ) millimetres.
Don't forget the minus sign.
If you don't object to fractional AWG numbers, and by going the other way
around -
AWG = 20 * Log ( 0.3284 / inches ), or
AWG = 20 * Log ( 8.25 / mm ).
Worked any good DX lately ?
--
Regards, Reg G4FGQ
QTH:- 7 miles west of B'ham city centre.
Above long disused coal mine.
But still a 'metal-bashing' district.
Refer to website : -
http://www.btinternet.com/~g4fgq.regp
Tom Bruhns <to...@lsid.hp.com> wrote in article
<6uomli$s...@hpcvsnz.cv.hp.com>...
Tom Bruhns
Adding some more perhaps useful trivia to what I wrote yesterday:
: Joe Dubner (dub...@comtch.iea.com) wrote:
: : Wes Stewart N7WS <n7...@azstarnet.com> wrote:
: : > If the reference you are looking at is in the US, then the numbers
: : > refer to AWG (American Wire Gage).
: : > A fairly accurate conversion follows:
: : > Diameter in inches = 10^(-0.05035 * AWG_number - 0.4884)
: : > Diameter in millimeters = 10^(-0.05035 * AWG_number + 0.9164)
: : > For guages larger than 0, use negative values, ie 000, use -2
: : A somewhat related and easy-to-remember rule of thumb: for every
: : increase in 3 wire gage sizes (i.e. #30 to #27), double the CMA
: : (circular mil area), weight (per unit length), and current capability.
: : Resistance (per unit length) will be halved.
: : If one can remember that #30 AWG has a CMA (circular mil area) of
: : approximately 100 (actually it's 101) and #10 AWG measures about 1 ohm
: : per 1000 feet and can handle 15A, one could construct a wire table from
: : scratch!
First, thanks to Reg for the history lesson! It's also interesting that
AWG is known as B&S gauge (Birmingham and Stubbs??)
For a reference point, it's probably useful to remember 36 gauge as
_exactly_ 5 mils diameter. I understand that AWG is defined as
exponential thru that point and 0000 gauge = 460 mils diameter.
That means that, by definition,
d(mils) = 5 * 92^((36-G)/39)
Another useful approximation I have noted (but that was before I
started thinking in terms of dB!) is that for copper wire near
room temperature,
R(1000 feet) approx.= 10^(0.1*gauge - 1)
which remarkably has only integer powers of 10 in the constants!
Of course, I've noted all of these little factoids in the wire
table I always use, and not committed them to memory, so I end up
using the table rather than the formulas anyway. ;-) But...the
formulas are a good way to put the wire table in my programmable
calculator.
--
Cheers,
Tom
tom_b...@hp.com
Reg Edwards
First, thanks to Reg for the history lesson! It's also interesting that
AWG is known as B&S gauge (Birmingham and Stubbs??)
Good guess but wrong. B&S = Brown & Sharpe of
measuring instruments fame, such as micrometers.
But I suspect you already knew that.
=======================================
> Of course, I've noted all of these little factoids in the wire
> table I always use, and not committed them to memory, so I end up
> using the table rather than the formulas anyway. ;-) But...the
> formulas are a good way to put the wire table in my programmable
> calculator.
I took an interest in this thread because I've had two or
three requests from the US to include inches, feet and AWG
in my antenna and coil winding computer programs.
But, on balance, the risk of introducing program errors, the
amount of programming work involved, and the quality
control checks needed, would not be worth the production
and re-issueing labour. So, over there, you really must try
to get fixed up with the metric system. It's the 'IN' thing.
Had any good DX recently ? I havn't !
--
Regards, Reg G4FGQ
http://www.btinternet.com/~g4fgq.regp.
.
Tom Bruhns
: I took an interest in this thread because I've had two or
: three requests from the US to include inches, feet and AWG
: in my antenna and coil winding computer programs.
: But, on balance, the risk of introducing program errors, the
: amount of programming work involved, and the quality
: control checks needed, would not be worth the production
: and re-issueing labour. So, over there, you really must try
: to get fixed up with the metric system. It's the 'IN' thing.
There's a very useful DOS coil program that's "shareware" (but
the "fee" is extremely reasonable. ;-) that does the calcs in
inches, and in fact makes it very easy to calc for coils wound
on standard US machine screws. It will give you parallel
and series resonance frequencies and Q...all of which differ
slightly from the values Reg's coil program yields. (Reg:
I hope to do some tests to find out which is closer for one
or two practical coils, but right now it's a very low priority
for me.)
--
Cheers,
Tom
tom_b...@hp.com