TIG Welder For Material Type Metal Stainless Steel Steel For Maximum Material Thickness 5/8 in (Steel) For Minimum Material Thickness 3/250 in (Steel) Input Frequency 50/60 Hz Max Input Current 400 A Phase Single-/Three-Phase Polarity DC Series Maxstar 400 Stick Welding Maximum Output Current 300 A (Single-Phase) 400 A (Three-Phase) Stick Welding Minimum Output Current 3 A (Single-Phase) 3 A (Three-Phase)