The Lincoln stick welder Idealarc R3R-400 Description: Substantial amperage ranges include the R3R-400 at 60-500 amps; Easy to operate - Calibrated current control knob makes procedure setting simple and easy; Polarity switch, voltmeter and ammeter are standard on the K1285-16 R3R-400; Arc gouge with the R3R-400 using up to 5/16 in. (7.9 mm) diameter carbon electrode; Smooth arc - Makes it easy to weld with mild steel, low hydrogen, stainless steel and hardfacing electrodes.