Has Electric wire gotten smaller for the same guager?

Since it is too hot to play outside I was stripping some wire in recycle box. It looked like some of the old 12 gauge was bigger than the new stuff. So I stripped exactly 1 foot of 12/2 wg 20 years old and 2-3 years old and weighed it on my postal scale. They sure as heck did not look the same or weight the same.
As the insulation has gotten better and more heat resistant has the wire been down-sized?
Colbyt
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Postal scale? Probably not accurate enough for this measurement. Anyway, if you stripped it the insulation doesn't matter in this calculation.
1 foot of 12GA copper wire should weigh .316 oz. What did your samples weigh?
AWG Copper Wire Table AWG Diam. (mils) Circular mils Ohms/1000ft Feet per Pound 12 80.8 6529 1.619 50.59
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wrote:

Accuracy is not really a concern when comparing two weights on the same scale.
Precision is what matters. One should either weigh the same thing several times to see if the reading is always the same, or average the readings if they are different**. Same thing with the other item.
**If the readings are different from one time to the next, one should tap the scale with the weight on it, to see if the reading changes. If it does, it may be possible to lubricate the scale. That may eliminate the problem. If the problem exists or persists, it's better to tap the scale every time to see where the reading comes to rest.
All that said, my postal scales have been quite consistent in its readings. They are adjustable to get better accuracy, but like I say, accuracy is not important when comparing two weights on the same scale.

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I have noticed that insulation is now thinner than on wires made 20 or 40 years ago.
wrote...

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I would love to correct that typo in the subject but that would make a new thread.
I snipped a comment or two from Handyman's post also. Will address that down the page.
10 foot of 12/2 wg uf (30 foot total) yielded 9 OZ that is just under your 9.48 figure. 1 foot #4 single wire yielded 2 oz. 1 foot old se6 (3 wires 3 foot total) yielded 4.20 OZ. 1 foot old 12/2 wg (3 foot total) yielded 1 oz. 1 foot 8/3 wg (3 @ 8, 1 @ 12? ) yielded 3oz.
1 foot new #4 AL gave me a whole 1oz. Most likely not worth the effort. I know why the electrician did not take the leftovers.
<quote>That's fine, but I do think the copper wire is thinner too, and I dont understand how that could be. 12 gauge needs to BE 12 gauge. The only thing that I can think of, and this is just a guess..... Modern wire is a TRUE 12 gauge. Copper is expensive these days, whereas the older wire was not as precise, and as long as the thinnest sections were 12 gauge, thicker sections were fine. Like I said, just a guess....</quote>
I have to agree with everything you said in the quote. Not all the old stuff I see is that way. But some of it sure the heck is.
Colbyt
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I've had one experience where it seems like the old wire is thicker than new wire. I had found a place in my crawl space where someone had spliced 2 wires together just by putting caps on them - just inches below the paper backing of insulation. I put the connection inside a box, but this made one of the wires too short and I had to replace it. Stripped of insulation, I held the copper wire up against a couple of samples - it was thicker than 14 gauge, and about the same size as 12 gauge, so I used 12 gauge to replace it. But then I saw the old wire had "14 gauge" stamped on it. So yes, I do think some older wires are thicker than newer wires. Seems strange to me, because copper is copper and should still be exactly the same over the years.
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I have to agree with you. The insulation is stronger and thus thinner. That's fine, but I do think the copper wire is thinner too, and I dont understand how that could be. 12 gauge needs to BE 12 gauge. The only thing that I can think of, and this is just a guess..... Modern wire is a TRUE 12 gauge. Copper is expensive these days, whereas the older wire was not as precise, and as long as the thinnest sections were 12 gauge, thicker sections were fine. Like I said, just a guess.....
I dont think they can make wire thinner due to regulations. It's not like lumber where a 2x4 is now 1.5x3.5 and 1/2" plywood is actually 7/16 or something like that. Actually, I still cant understand how they can call 7/16 plywood HALF INCH, (there ought to be a law). When it comes to dimension lumber I guess we are all so used to it that we dont think twice about it, and the old TRUE 2x4 was rough, whereas the new ones are planed.
I was getting off the topic there, but making wire thinner seems like it would be a hazzard and the NEC would jump all over them manufacturer. At the same time, I have noticed that some old wire is thicker and have always wondered about this myself. As I said earlier, all I can figure is that some of that older wire was actually oversized. Oversized is safe, and back then copper was fairly cheap. I should buy a micrometer and start checking some of it. Anyone else have one and some old and new wire laying around? It would be interesting to find out for sure, however I think my visuals are pretty accurate as far as some of the older wire being thicker.
I have been a handyman for over 30 years, and done my share of electrical work, so I know what I have seen.
The Handyman
On Wed, 1 Aug 2007 16:35:18 -0400, "Colbyt"

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My guess it that they devised a better way to manufacture the wire, perhaps with less micro-fissures, so that modern wire has less resistance than older wire. Thus thinner wire can safely carry the same current. But that too is just a guess...
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Colbyt wrote:

You may be right but maybe the old wire was not manuafactured to as tight a specification. In other words it didn't matter to them if it was a little big. I suppose the best way to measure is with a micrometer and see if the new is less than specified in std's.
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