220 welders can supply more amprage for welding
110v hobart model 140 = 140 amps
220v hobart model 180 = 180amps
more amps = abality to weld thicker metal and somtimes a higher duty cycle
duty cycle is the time you are actualy welding versus the time the welder must be allowed to cool down.
The other thing to consider is being able to use your welder other places 220v may not be available where you need to weld ( at a freinds shop, or an onsite repair.) The main reson that I went with 110 is because I mostly weld thin metal and can use my welder anwhere that has an outlet but I can still weld fairly thick metal if need be.
