How can I tell if the wires are 14 gauge or 12 gauge?

I have a metal encased electrical wire, I think its 14/3, how can I be sure. I don't have the romex yellow (12 gauge) or white (14 gauge) which makes it easy to determine. Is there data on the wires telling me what gauge they are?
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Compare it to a wire that you know is either 12 or 14.
Or use a wire stripper: if you put 12-gauge wire into the 14-gauge hole on a stripper, the teeth will cut through the insulation, and bite on the conductor. Conversely, the teeth on the 12-gauge hole will not cut all the way through the insulation on a 14-gauge wire.
--
Regards,
Doug Miller (alphageek at milmac dot com)
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On 19 Sep, 15:24, snipped-for-privacy@milmac.com (Doug Miller) wrote:

-- Or use a wire stripper:
...with the power off of course!!
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On Sep 19, 3:24 pm, snipped-for-privacy@milmac.com (Doug Miller) wrote:

If you compare it to another wire, bend it. 14 bends easier than 12.
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No need to bend it. A visual comparison is easily enough to tell the difference.
--
Regards,
Doug Miller (alphageek at milmac dot com)
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on 9/19/2007 8:04 PM Doug Miller said the following:

If one has samples of both.
--

Bill
In Hamptonburgh, NY
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You need only one sample -- as long as you know what it is.
--
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Doug Miller (alphageek at milmac dot com)
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Metal encased in what? EMT conduit, BX, Greenfield, or ?????? You are much too vague. Did you try to read the wires themselves? In Conduit they are usually labelled. Or put a micrometer on the copper wire ends.
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If you can trace them to a breaker, a 14 should be on a 15 amp. Of course that's not conclusive since a 12 could be on a 15 amp or a 20 amp, but if the work was done correct to start with, a 14 wouldn't be on 20 amp.

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