Triple taps and lighted outlets are nice, but it has to be able to carry the current.

Let's talk about how to select a cord for your welder.

  2017 March 19     Metal & Shop   Welding


How many times have you wished you could bring the welder to the workpiece, instead of the other way around? 

Generator welders are great, but they're expensive.  The extension cord is a lower-cost option to get more reach.

This article is for people who have welders that are labeled 110, 115, 120, and 125 volt.  Almost any modern device that says "110", etc., is actually designed for 120 volts RMS.

So, I'm just going to call these 120-volt welders. 

Now let's see if there are any extension cords that would work.

Cheap Cord Fail

Common extension cords are typically rated for no more than thirteen amps. 

These cords have higher resistance, which causes a voltage drop.  Your welder will probably shut off a lot if you're running it near the top of its output range.  You will have to turn down the amps, which can make for weaker welds.  The electrode may not even hold an arc at the lower amperage. 

Cheap cords can also heat up (dangerous).

10-Gauge Cords

Many extension cords are 16-gauge or 14-gauge wire.  As the number gets smaller, the wire diameter increases. 

10-gauge is usually better, but some 10-gauge cords have no more current rating than a 12-gauge cord. 

Here, I think, is why:  to make the cord more flexible, they use wires with many fine strands instead of fewer, heavier-gauge strands.

30-core wires have less current-carrying capacity than, say, 20-core wires.  Fine-strand wires should have more close-packing ability, but maybe at some point that's not true (I haven't done the math, but I'm sure someone else has.)  The lower rating could have to do with strand breakage, oxidation, or something else.

The cord shown on this page is like that.  I was unable to find out for certain, but I think the wires are 30-strand.  That could explain why it's only rated for 15 amps.  They market this cord as 15 amps, which is OK, but if you're going to buy a 10-gauge cord, it might as well be a good one.  Twenty amps or nothin'!

Special Connectors

You're probably familiar with the standard NEMA 5-15 plug, shown here. 

Your welder might have a plug like this, but it should still be plugged into a 20-amp circuit for best results.

Proper extension cords that can handle 20+ amps will generally have different connectors.  These connectors won't plug into your common household NEMA 5-15 outlet. 

Some generator extension cords have 30-amp connectors.  A 20-amp outlet won't accept these connectors, either;  you would have to use adapters. 

That's sort of a hassle if you just want 20 amps.  Next up, simple solution.


So we're looking for a 10-gauge, 20-amp cord with NEMA 5-20 connectors.  It should be at least fifty feet, because 25-foot cords run out too quickly when working outside. 

There are two easy solutions that I've found:  This cord and this one.  Neither one of these is cheap, but then again:  fifty feet at 20 amps!  Long extension cords that can handle high current tend to be expensive.

I just noticed they also make a 100-foot one.

The NEMA 5-20 will not plug into a standard 5-15 outlet.  It has one of those sideways prongs.  That should be OK, since the 20-amp outlet for your welder should be the same kind of connection.  So go for it.


Using the wrong extension cord can be ineffective, dangerous, or both.  Get a proper cord, and it's one less frustration to deal with.

I know;  a decent extension cord will cost you almost as much as a good 120-volt welder.  This is not one of those areas to skimp, though.  If you want to run 3/32" 7018's and make good welds, then you have to let your welder get all the power it needs. 

Get a proper extension cord for your welder and the problem is solved. 

I hope you've enjoyed this article and found it helpful.  You can really help me out by using the links on here to purchase your gear.  Thank you!


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