Process comparison
MIG Welding vs TIG Welding
MIG is faster and far easier to learn; TIG is slower but gives complete control over heat and filler, which is what thin material and exotic alloys need.
GMAW vs GTAW at a glance
| MIG Welding | TIG Welding | |
|---|---|---|
| AWS designation | GMAW — Gas Metal Arc Welding | GTAW — Gas Tungsten Arc Welding |
| Filler delivery | Continuously fed solid wire plus shielding gas. | Non-consumable tungsten arc, filler added by hand. |
| Polarity | DCEP for all solid-wire GMAW | DCEN for steel and stainless; AC for aluminium and magnesium |
| Typical amperage | 50–350 A depending on wire size and transfer mode | 5–300 A depending on thickness and material |
| Typical voltage | 16–24 V short circuit, 24–30 V spray | 10–20 V |
| Positions | All positions in short-circuit and pulsed transfer; flat and horizontal only in axial spray | All positions |
| Deposition rate | High — continuous feed with no stub loss | Low — the slowest of the common processes |
| Shielding | External shielding gas, so it cannot be used in wind without shelter | Argon or argon-helium, external gas only |
| Skill level | Easiest of the arc processes to reach a usable weld with | The most demanding; requires coordinated use of both hands and a foot pedal |
| Slag | None | None |
Which should you use?
MIG feeds filler automatically while the gun holds arc length for you, so a beginner produces a usable weld in an afternoon and a shop produces a lot of metal per hour. TIG separates heat from filler entirely — the pedal controls one hand, the rod controls the other — which gives precision no other process matches, at perhaps a quarter of the travel speed. The practical rule: if the joint is thick, repetitive, or on a production schedule, MIG. If it is thin, visible, exotic, or a root pass that must be perfect, TIG.
Choose mig welding when
- Production fabrication where throughput matters
- Material over about 1/8 in
- Beginners and shops with mixed skill levels
- Long welds on clean carbon steel
Choose tig welding when
- Thin sheet and tubing where burn-through is the risk
- Stainless, aluminium, titanium and nickel alloys
- Welds that will be visible or inspected
- Root passes on pipe and sanitary tube
Strengths and limitations
MIG Welding
Advantages
- Fastest of the common processes to learn to a usable standard
- High deposition rate and high operator duty cycle
- No slag to chip between passes
- Works on material from 24 gauge sheet up to heavy plate
Limitations
- Shielding gas blows away in wind above about 5 mph
- Requires clean base metal — rust, paint and mill scale cause porosity
- Equipment is less portable than a stick machine
- Short-circuit transfer can produce cold lap on thick material if settings are wrong
TIG Welding
Advantages
- The highest weld quality and the best control of any arc process
- No spatter and no slag
- Welds almost any metal, including aluminium, titanium, magnesium and nickel alloys
- Filler metal is optional — thin edges can be fused autogenously
Limitations
- Slowest deposition rate of the common processes
- Steepest learning curve
- Base metal must be genuinely clean
- Cannot be used in wind without shelter
MIG Welding vs TIG Welding — common questions
Is TIG stronger than MIG?
A sound weld by either process develops full joint strength. TIG's advantage is control, heat input and cleanliness — not strength. A properly executed MIG weld is not weaker.
Which is harder to learn, MIG or TIG?
TIG, by a wide margin. It requires coordinated use of both hands and a foot pedal. MIG requires only gun angle and travel speed, because the machine holds arc length for you.
Can MIG weld aluminium?
Yes, with a spool gun or push-pull torch and 100% argon. The soft wire birdnests in a standard liner on a long gun, which is why the dedicated feeder matters.
Which is cheaper to set up?
MIG. A capable MIG machine costs less than an equivalent AC/DC TIG machine, and TIG also needs a foot pedal, tungsten, cups and usually a water cooler for sustained high-amperage work.
Full process guides
MIG Welding (GMAW)
MIG welding feeds a solid wire electrode continuously through a gun while shielding gas protects the puddle — the fastest process to learn and the standard for production fabrication on clean steel.
TIG Welding (GTAW)
TIG welding strikes an arc from a non-consumable tungsten electrode under argon shielding, with filler added by hand — the slowest process and the one that produces the highest quality welds.