Millermatic® 251


Welds material from 22 gauge to 1/2 in thick in a single pass. Perfect for metal fabrication, maintenance and repair, farms and ranches.

General Information: 
  • Miller's patent-pending Active Arc StabilizerT provides excellent starts proven superior to the competition.
  • Adjustable run-in control is individually settable for both MIG and spool guns. Set at the front panel, this easily accessible feature allows the user to optimize starts to their application.
  • Self-calibrating digital meters allow presetting of voltage and wire feed speed. With spool gun, wire speed meter displays setting - a feature not available on competitive units.
  • Easy-to-use Digital Operator Interface and attached parameter chart makes it simple to set weld parameters.
  • Add the optional SpoolmaticT 15A 0r 30A spool gun for aluminum welding. No extra module to buy or install. And with Miller's exclusive Gun-On-DemandT, simply pull the trigger for either gun and your ready to weld. No wasted time installing modules and using toggle switches.
  • Convenient built-in gun and cable holder and consumable compartment
  • Industrial, dual-gear-driven, aluminum drive system features no-tool, quick-change reversible drive rolls and an easy-to-set, scaled tension knob
  • Line voltage compensation keeps welding parameters constant even when input voltages change ±10%. Eliminates the need to change welding parameters throughout the day.
  • Fan-On-DemandT operates only when needed reducing noise, power consumption, and the amount of airborne contaminants pulled through the machine
Standard Accessories: 
  • Power Source
  • 12 ft (3.7m), 250 amp M-25 MIG gun
  • Work cable and clamp
  • Factory-installed dual gas solenoids
  • Argon mix regulator/flow gauge w/hose
  • Industrial power cord and plug
  • Factory-installed running gear/cylinder rack
  • 030/.035 in reversible dual groove drive rolls
  • Extra contact tips
  • Set-up and operation video


  • Requires 1-Phase Power
  • Rated Output

  • 200 Amps at 28 VDC, 60% duty cycle
  • 250 Amps at 28 VDC, 40% duty cycle
  • Welding Amperage Range

  • 30 - 300 Amps
  • Wire Speed

  • 25 - 700 IPM (0.64 - 17.8 m/min)
  • Net Weight

  • 215 lb (98 kg)