So I was looking for some electronics projects to build and I came upon a thing talking about making a small ac welder with the transformers out of microwaves so I thought I would give it a try. I mentioned this to my dad (who is a welder) and he told me he had this little crappy welder that someone had given him about 10 years ago and that I could have it for parts. I took it apart to clean it and see what I could use from it and it turns out its exactly the same thing that I was going to build only it used one big transformer. So I decided I would get it running and tweak it. The main thing wrong with it right now is the on off toggle switch that was on it was broken so I was going to put another one on there but the switch is rated 10A @ 250V and 20A @ 120V and I can't find a switch anywhere that has these specs. All the switches I find are either something like 10A@250V & 15A@120V or they're like 20A@120V & 6A@250V.

So my question is since the welder plugs into 120AC would it be better to look for a switch thats rated for 10A@250V or one for 20A@120V?

wow that is exactly what I needed, thanks