Where else can I buy wire gauge samples to help determine sizing? Lowes and Home Depot will not do it when you ask to cut wire gauges for each about 1 foot. I don’t want to buy a roll that is more than 10 foot long. Too expensive. Is there a chart with an actual size? I’m new to Texas Home Inspection and on training now.
Try a local hardware store in your area if there are any left. Money is money and the big box stores are lazy.
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Inspector outlet, Inspector wire gauges
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I thought about those too, but shouldn’t we keep in mind the thickness of the insulation? In other words, measure metal only and not the insulation because it may vary. I don’t know for sure.
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Metal only. Not sheathing nor colors.
Videos - Inspection Gauges (inspectionwiregauges.com)
Inspection Gauges - Home (inspectionwiregauges.com)
John sells them. click at the botttom.
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Ask your friendly electrician. Maybe he will save you some samples?
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Actually, I need to determine wire sizing with observing while inspecting the main/service panel. In Texas, we have to compare it with eyes, not the tool to measure it unfortunately.
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As Scott mentioned above, also reach out to a local electrician. A few snips of wire may be worth his/her time for being added on a vendor list. 
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You can also learn the color code of wire sizes.
you can also determine the wire size by the color of the sheathing.
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Much appreciated guys! I’m pretty good with colors to determine. Lol!
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The color code is not necessarily a standard. It also does nothing to help someone with wiring made before colored sheathing.
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If safe to do so, you can also follow the wire back to the sheathing where you may find the size printed. It’s not always possible though.
Some big box stores have retired tradesman working in their appropriate aisles. I went until I found a retired electrician in HD. When I explained to him that I was trying to become more familiar with the wire sizes to become a home inspector, he liked the idea and was kind enough to go through the trouble of cutting one foot pieces.
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Minor tip - If I am not sure of the difference between 12 and 14 gauge, I lightly push on them. 14 gauge distinctly has more deflection than 12 gauge. For some reason I had a harder time distinguishing between those 2, and that’s what I came up with. Ok, ready for the MB flames concerning safety…
I have a set of those gauges, you use them on the wire insulation, not the bare wire.
they are all set for different types of wires, and insulation.
If wired properly and the panel is within a ‘finished’ wall, it should not be possible as there is a limit on sheathing length that enters the panel. I don’t remember the exact length, but it’s certainly not enough to even get a hint at the wire size.
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There is no limit on the amount of sheath in the panel, except that there must be 6" of free conductor outside the sheath. There is a minimum of 1/4".
That’s correct the 1/4 " requirement was added to the 2020 NEC. Prior code cyes has no such requirement for a NM cable entering a panel.
Perhaps this is what I was thinking. I rarely see more than a 1/4" to 1/2" of sheathing inside a panel, except for when scraps are used for identification of a circuit!
Thanks for the correction.