Welders in this category cover the four main arc processes — MIG, flux-cored, TIG and stick — plus multi-process machines that cover several at once. The choice between them follows from the material, the thickness and whether the work happens indoors or in the field.
For mild steel sheet and light fabrication, MIG is the fastest and easiest process to learn. For outdoor work and windy conditions, flux-cored wire runs without shielding gas and will not be blown out. For stainless, aluminium and thin gauge work that will be inspected, TIG gives the control and appearance that the other processes cannot match. Stick remains the practical choice for heavy plate, dirty or rusty steel and repair work in the field.
Specifications that matter: output amperage range, duty cycle at rated output, input voltage (120 V or 240 V), and whether the machine includes a spool gun or high-frequency start for aluminium and TIG. A 140 A MIG machine on 120 V will handle up to roughly 3/16 in steel on a light duty cycle; anything heavier needs 240 V input and a higher amperage machine.
Multi-process machines run MIG, flux-cored, TIG and stick from one power source. They trade peak output for flexibility and are the practical choice for a shop that does varied work or a mobile welder who cannot carry three machines. The limitation is that a multi-process unit at a given price generally will not match a dedicated single-process machine at the same price on output or duty cycle.
