MIG vs TIG welding: differences and how to choose
There is no "best" welding process, only the one that fits the metal, the thickness and where you will work. MIG and TIG are the two names heard most, and they get mixed up. Here is what actually changes between them, and where stick welding comes in.
MIG is the easier one to learn and the faster one: the wire feeds itself. TIG is the more precise and cleaner one, best on stainless, aluminum and thin work, but the hardest, because you coordinate torch, filler rod and pedal. Stick is the simplest machine and handles outdoor work.
MIG and MAG: same machine, different gas
Both use a continuous wire the machine feeds for you. The difference is the gas:
- MIG (inert gas): pure argon or helium. Mainly aluminum and other nonferrous metals.
- MAG (active gas): CO2 or argon/CO2 mixes. C25 (75% argon, 25% CO2) is the standard for mild steel.
In the US everyone says "MIG" for both, though welding steel with a mix is technically MAG. Gases are explained in MIG welding gas compared.
TIG: the electrode that does not burn away
In TIG the arc comes from a tungsten electrode that does not melt. When you need filler, you feed a rod with your other hand, and many machines offer a foot pedal to control current during the weld. That three-way coordination is why TIG is hardest to learn, and why it commands respect in the shop. On aluminum you run AC; on steel and stainless, DC with the electrode negative (DCEN). MIG, by contrast, runs with the gun on electrode positive (DCEP).
The difference in one sentence
In MIG the wire is both the electrode and the filler metal, and the machine pushes it. In TIG the electrode (tungsten) only makes the arc, and the filler enters separately, from your hand. That is why MIG is faster and TIG gives more control.
Side-by-side comparison
| Process | Best for | Learning curve | Gas cylinder needed? |
|---|---|---|---|
| MIG (GMAW) | Auto body, thin sheet, fast work, beginners | Low to medium | Yes with solid wire; no with self-shielded flux-cored wire |
| Stick (SMAW) | Gates, railings, structures, thick steel, outdoor work | Medium | No |
| TIG (GTAW) | Stainless, aluminum, fine work and a perfect finish | High | Yes (argon) |
Table 16.1 of the e-book The Welder's Forge.
| Detail | MIG | TIG |
|---|---|---|
| Filler | Wire feeds automatically | Rod fed by hand |
| Hands and feet | One hand on the gun | Two hands, often a foot pedal |
| Speed | Fast | Slower; less productive above 5/16–3/8 in (8–9.5 mm) |
| Cleanliness of metal | Tolerates some mill scale and light rust | Needs spotless metal |
| Spatter and slag | Some spatter, no slag with solid wire | No spatter, almost no slag |
| Lens shade | Shade 10–12 at 60–300 A | Shade 9–11 at 15–80 A |
Table 2.1 of the e-book The Welder's Forge (shade values, excerpt); chapters 4 and 5.
The complete e-book
Reference tables, stick, MIG/MAG and TIG technique and safety in one PDF, written in plain American English.
Stick: the all-rounder
A simple machine, no gas, and it works in wind, on site and in every position. It takes a steady hand to control the arc and it leaves slag. See the steps in how to stick weld.
Which one should you start with?
- Home shop, mostly sheet metal and cars: MIG with shielding gas. Compare machines in best welder for beginners.
- Gates, railings and thick steel on a tight budget: stick, or gasless flux-cored wire.
- Stainless and aluminum with a first-rate finish: TIG, but after you have built some hand skill. Start with TIG welding for beginners.
- Interested in working in industry: the usual route is to master stick in all positions, then add MIG/MAG and TIG, and pursue welder performance qualification to the procedure the employer or code requires. The e-book explains how qualification works; it does not promise a job.
Decide first what you will weld: metal, thickness and whether you will work indoors or out. The machine comes after. A 120 V machine and a 240 V machine are very different in what thickness they can handle, so read the nameplate for input current and duty cycle, and match your circuit to it.
Other processes you will hear about
- Oxyacetylene (torch): needs no electricity. Still used for repairs and brazing.
- Submerged arc: automatic, for heavy thickness (shipyards, pressure vessels).
- Resistance (spot): the backbone of automotive production, mostly done by robots.
- Brazing and soldering: join without melting the base metal. Plumbing, refrigeration and electronics.
All of these are covered in the e-book, and none replaces hands-on training with someone who can watch you weld.
Frequently asked questions
Which welding process is easiest to learn?
What is the difference between MIG and TIG welding?
Which process is cheapest to start with?
Which process should I use on stainless and aluminum?
Want all of this in one PDF?
The e-book The Welder's Forge covers stick, MIG/MAG and TIG from the first arc to the shop floor, with reference tables and technical figures, in plain American English.
PDF for phone, tablet or computer · instant access · 14-day guarantee