Miller Millermatic 255

Last updated: November 1, 2026

Miller Millermatic 255
2.6/5#7 of 7 in 240 V welders
2.6

A professional shop MIG for fabricators who weld thick steel and aluminum all day. It is overkill for weekend repairs.

  • 350 AOutput
  • 60% at 230 A, 40 °CDuty cycle
  • MIG, flux-coreProcesses
  • 240 VInput
Check price at Amazon$4,352

Price checked November 1, 2026. As an Amazon Associate we earn from qualifying purchases.

Pros
  • Holds 230 A for 60% of the time, so long welds on thick steel rarely stop
  • Welds 1/2 in steel in one pass
  • Pulsed MIG and push pull gun support make it a strong aluminum MIG
  • Auto-Set Elite sets up from wire, gas and thickness for quick job changes
  • Inverter is much lighter than older shop MIG welders
Cons
  • Costs far more than other 240 V MIG welders
  • Needs a 240 V circuit; no 120 V option
  • MIG only, no stick or TIG

How it scores

The rating comes from 5 measured or published factors, each scored 0-100 against fixed reference points for its input voltage. How we rank explains each one.

Specifications

Model number907734
Output
Input voltage240 V
Maximum output350 A
Rated duty cycle60% at 230 A, 40 °C
Thickest steel, one pass0.5 in
InverterYes
Processes and wire
Gas MIGYes
StickNo
TIGNo
Spool gun readyYes
Wire sizes0.023 to 0.045 in
Synergic settingsYes
Build
Weight84 lb
Warranty3 years
Released2019-02

Alternatives in this input voltage

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