What is this type of wire called?

I've been looking for a longer cord, or just bulk wire without ends for a table saw. I'd like the cord flat as it has to run along the floor, and most extension cords are fat and round, while most appliance type cords are too short. (Or can I use romex?)

  • "Why are appliance cords (like a dryer or oven) usually flat?" I would suspect it is because they are heavy gauge wire and they live a tight space between an appliance and a wall.
    – Alaska Man
    Mar 24, 2021 at 19:30
  • 2
    "Romex" is stiff and the insulation needs protection from 'wear & tear'. It's not made to be walked on or left on the floor where it'll get scuffed & damaged.
    – brhans
    Mar 24, 2021 at 19:31
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    How long and what gauge do you need it to be? 15' 14/3 flat extension cables seem to be readily available, but I have no idea if that's good enough for your table saw. Here's an example of one: allelectronics.com/item/ext-615/15-extension-cord-14/3-spt-3/…
    – Nate S.
    Mar 24, 2021 at 20:38
  • 1
    And here you can find them up to 25 feet: amazon.com/POWTECH-Conditioner-Appliance-Extension-3-PRONGED/dp/…
    – Nate S.
    Mar 24, 2021 at 20:43

3 Answers 3


Parallel cables are designated the NEC as lighter duty than most round cables. Cables that are flat are designated as Type SP, SPT-1,2 or 3, Service duty Parallel or Service duty Parallel Thermoset 1,2, or 3 grade level. Service duty indicates Not Hard Usage, while most round cables (SExx, SOxx, or SJxx) are designated Hard Usage or Extra Hard Usage.

The primary construction deficiency you will find with Parallel cables is single layer of insulation. Hard Usage cables have insulated wires inside an insulating jacket.

  • What is meant by "hard usage"? For my application, it will be on the floor, probably taped in place, never moving. Occasionally, a light cart or something would roll over it.
    – joeking
    Mar 25, 2021 at 2:22
  • Don't know specifics of rating, but know that OSHA requires hard use or better for tools, appliances, and temp lighting [1926.405(a)(2)(ii)(J)]. Mar 25, 2021 at 2:45

I would suggest not using romex. It has solid core and is not designed to bend and flex as is the case with extension cords.

Consider running the extension cable along the ceiling instead of the floor then the shape of it will matter less.

  • I have an overhead cord now - but I don't like it - it often gets in the way.
    – joeking
    Mar 25, 2021 at 2:25

If you want to create a custom cord get the proper type some like SJ hard service junior , this I consider medium duty or plenty for residential use(300v rated) I work in a industrial environment so I use SEOOE/SOOW hard service oil damp extra hard service cord (600v rated). for a tool like a saw choose a heavier wire gauge 14 gauge if it’s not overly long and 12 awg if it is longer. Extension cord has a higher current rating but it is not contained in walls with insulation so it a smaller gauge is less likely to overheat . see table 400.5.A.1 for the numbers.

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