MIG and Flux-Core Welders

MIG welders feed solid wire through a gun under shielding gas from a bottle; flux-core machines run wire that shields itself, so they need no bottle and tolerate a breeze. Most MIG machines run both. Miller's rule of thumb, 1 amp per 0.001 inch of steel, ties a machine's output to the thickness it welds in one pass: about 125 amps for 1/8 inch.

Compare duty cycle at the amps you'll use, not at the peak: a rating is always a percentage of 10 minutes at a stated current. Makers' thickness claims often mean multiple passes or flux-core wire; each row quotes the maker's wording.

The amperage selector turns a thickness into a starting current and wire size, and lists machines rated for it.

What are you welding?

Check before you buy

• 120 V or 240 V?. Household outlets cap most machines around 140 amps. What each can weld.
• Check the duty cycle. Minutes of welding in each 10 at your amps. Duty cycle calculator.

MIG welder spec sheet

Figures are the makers' own, quoted with their conditions on each product page. Prices change; each product page links to the current price.