In article ,
says...
According to krw :
Thanks for the tip. But what does SO and SJ mean?

It's a rubber jacketed stranded wire cable. I believe SO insulation is
rated at 300V, where SJ is 600V. For 220V (8/3 w/ground) operation, I
think you need SJ.

SJ is medium duty. SO is heavy duty. SOW is "heavy duty, wet
locations".

SO is to be preferred. I'd only recommend SJ if the welder was
going to be stationary, and you can keep the cord out of the way
of getting cut/hit/splattered/walked on.

Interesting enough to look up. ;-)

http://www.stagelight.com/toolbox/cabspec.htm

Apparently SJ is lighter S (S = stranded), as you say. The 'O' is for
"oil resistant".

snip
A welder isn't going to need /3. It sounds like SO (or SJ)
8/2 would be the best choice.

I thought the SO had 8/3 and was replacing it. Still, 600V is needed,
IMO.

I _suspect_ you'd pay around $3-4/foot for SO 8/2. Some years ago,
I paid $1.50/ft for SO 10/2.

Keep it as short as you can get away with.

And/or go up a size.

NOTE that "Northern" (aka "Northern Hydraulics") probably has
welder replacement cords for a bit less than you can cobble them
together yourself.

[*] The fat things that come in all sorts of pretty colours, massive
molded connectors, and cost an arm and a leg.

;-)

--
Keith