MIG vs TIG Welding: Which One Should You Use?

MIG vs TIG comes down to speed versus control. MIG welding feeds a consumable wire that doubles as filler, so it runs fast and cheap on thicker steel. TIG welding uses a non-consumable tungsten electrode with filler added by hand, which gives tighter heat control on thin, stainless and reactive metals at a higher cost per foot.

Neither process is automatically stronger. That runs against a common assumption, and it matters when writing a drawing for any welded sheet metal fabrication: specifying TIG where MIG would pass raises unit cost and narrows which factories can quote.

Below, we walk through how the MIG welding process and the TIG welding process work, the advantages and disadvantages of each, which one is stronger, the right choice for aluminium, stainless and steel, why TIG costs more, and what to put on a drawing so that welding fabrication manufacturers quote the weld the part actually needs.

TL;DR / Key Takeaways

• MIG (GMAW) is faster and cheaper; TIG (GTAW) gives finer heat control and a cleaner bead.
• Weld strength depends on filler, fusion and procedure; sound MIG and TIG welds on the same joint perform alike.
• TIG costs more per foot, mainly in labour time.
• A drawing should define the weld requirement and name the process only where the design or code needs it.

What Is the Difference Between MIG and TIG Welding?

The difference between MIG and TIG welding is how the arc is made and how filler reaches the joint. Otherwise the two have a lot in common: both are gas-shielded arc welding processes, and both are standard joining stages in the metal fabrication process.

MIG welding (Metal Inert Gas, formally GMAW) feeds a continuous wire through the gun, and that wire acts as both electrode and filler. Because the machine does the feeding, the welder can move quickly along long seams. The shielding gas is usually 75% argon and 25% CO2, a mix that according to TWI stabilises the arc and aids penetration on steel.

TIG welding (Tungsten Inert Gas, formally GTAW) works differently. The arc comes from a tungsten electrode that doesn't melt, so the welder hand-feeds filler rod separately and controls amperage with a foot pedal. Pure argon is the usual shielding gas here, because tungsten is sensitive to oxygen and CO2, and that separate control of arc and filler is where TIG's precision comes from.

MIG vs TIG Welding: Side-by-Side Comparison

Put side by side, the advantages and disadvantages of each process line up neatly: MIG leads on speed and cost, while TIG leads on heat control, finish and thin material, and that split decides most applications. TIG also runs at roughly half MIG's gas flow, according to TWI's typical figures.

Factor	MIG welding (GMAW)	TIG welding (GTAW)
Electrode	Consumable wire, machine-fed	Non-consumable tungsten
Filler	Automatic, via the wire	Hand-fed rod (or none)
Shielding gas	75% argon / 25% CO2 (typical on steel)	100% argon (typical)
Gas flow	35–50 cubic feet per hour	15–25 cubic feet per hour
Travel speed	Fast	Slower (manual filler, lower deposition)
Finish	Some spatter, often ground or coated	Clean, little or no spatter
Fit-up tolerance	Bridges small gaps	Needs tight, clean joints
Best thickness	Thicker sections	Thin sheet and precision work

Is TIG Welding Stronger Than MIG?

TIG welding is not inherently stronger than MIG, even though it's often described that way. As Lincoln Electric explains, weld strength comes from complete fusion, the correct weld size and a filler of at least matching strength to the base metal. And both processes can deposit the same filler: ER70S-6 is classified under AWS A5.18 as both MIG wire and TIG rod.

Beyond the filler, joint strength depends on fusion, joint penetration, preparation, heat input into the heat-affected zone and the welding procedure. So a well-run MIG weld on a properly prepared V-groove can match a TIG weld on structural steel.

Where TIG does pull ahead is defect control. Its narrow arc makes lack of fusion, porosity and inclusions less likely on thin walls and reactive metals, which is why TIG dominates pipe root passes and welds that must pass radiographic (RT) or ultrasonic (UT) inspection.

With that in mind, two cautions apply when reviewing welded parts:

• A pretty weld isn't proof of a sound weld. A neat TIG bead can still hide lack of fusion at the root, which only inspection reveals.
• Heat-treated aluminium loses strength next to any weld. Unwelded 6061-T6 has a minimum tensile strength of 40 ksi, yet fabrication codes such as AWS D1.2 only require 24 ksi after welding, because the heat-affected zone softens whichever process is used. In that case, joint design matters more than the process.

Which Welding Process Is Best for Aluminium, Stainless and Steel?

Welding process selection usually starts with the base metal: in most cases, MIG is best for mild and carbon steel, while TIG suits thin stainless, thin aluminium and titanium. Thicker stainless and aluminium production work, however, often goes back to MIG for speed.

Material	Preferred process	Why
Mild / carbon steel	MIG	High deposition, strong welds, lowest cost on thick sections
Stainless 304 / 316, thin or visible	TIG	Tight heat control limits distortion and heat tint
Stainless 304 / 316, thicker production runs	MIG	Acceptable quality where appearance is secondary
Aluminium 6061 / 5052, thin sheet	TIG (AC)	AC current breaks up the oxide layer; control on thin sheet
Aluminium, thicker sections in production	Pulse MIG	Higher deposition for structural parts
Titanium Grade 2 / Grade 5	TIG	Reactive metal needs full inert shielding

Stainless deserves a closer look, because it moves more under heat than carbon steel. Austenitic stainless steel combines low thermal conductivity with high thermal expansion, which the British Stainless Steel Association names as the main cause of welding distortion. Since heat stays concentrated near the joint, TIG's precise heat input is the usual choice for thin or precision stainless parts.

Why Does TIG Welding Cost More Than MIG?

TIG welding costs more per foot of weld than MIG, mainly because it takes longer and needs more skilled labour.

TWI lists four drivers:

1. Lower deposition rates
2. More experienced (and more expensive) welders
3. Extra preparation work
4. Pricier consumables and machines.

In other words, TIG's higher operating cost is mostly labour time, driven by slower travel speed and a lower deposition rate. That said, no fixed multiplier holds across jobs. The gap depends on weld length, material, thickness and each factory's labour rate, so comparing quotes on the same drawing says more than any rule of thumb.

In practice, TIG earns its premium on visible stainless, thin aluminium, titanium and inspected joints. On painted mild-steel frames, on the other hand, it rarely does.

MIG vs TIG vs Stick: Where Stick Welding Fits

Stick welding (SMAW) is the third arc process that often comes up alongside GMAW and GTAW, and it's the practical choice for outdoor, site and repair work on thick structural steel, including rusty or dirty stock. Its flux-coated consumable electrodes need no external shielding gas, so wind isn't a problem. The trade-off is slag to chip off every pass and more filler lost to stub ends and spatter.

Flux-cored welding (FCAW) sits somewhere in between: it's wire-fed like MIG, and in its self-shielded form it needs no gas cylinder, just like stick.

When to Use MIG vs TIG Welding

Bringing material, cost and finish together, the typical applications split clearly: MIG is the default for steel that will be hidden, coated or produced in volume, whereas TIG is the choice where the weld is visible, thin or inspected.

Scenario	Use	Reason
Thicker mild steel, non-critical	MIG	Faster, lower cost
Welds ground flush, painted or powder-coated	MIG	Appearance is hidden
High volume, long seams	MIG	Deposition rate and fewer restarts
Outdoor or site welding	Stick or self-shielded FCAW	No external gas to blow away
Visible welds, no coating afterwards	TIG	Clean bead, little finishing
Pipe roots, pressure or leak-tight seams	TIG (often TIG root + MIG fill)	Consistent root fusion
Welds subject to RT or UT inspection	TIG	Fewer inclusions

Should the Drawing Specify MIG or TIG?

The drawing should define the weld requirement first (size, length, location, finish and acceptance standard) and name the process only where the design, customer or code requires it. After all, a note that only says “TIG weld all around” tells a factory which torch to pick up and nothing about what a good weld looks like. When the process does need locking, the weld symbol can carry it too, because AWS A2.4 reserves the tail of the symbol for a specification or process reference such as GTAW.

Clear weld notes matter because drawing interpretation is one of the recurring pain points in Haizol's buyer interviews. Weld notes are an easy place for misreadings to start, since a factory given no requirement has to choose one itself. The examples below cover the most common cases.

Requirement	Example drawing note
Size and extent	3 mm fillet, continuous, all around
Process freedom	Welding process by supplier unless noted
Process lock	GTAW required on exposed stainless seams. No process substitution without written approval
Finish	Visible welds uniform and spatter-free; grind flush where indicated
Stainless condition	Remove heat tint; passivate after welding
Integrity	Leak-tight; inspect per the named standard
Governing standard	Weld per AWS D1.1 (steel), D1.2 (aluminium) or D1.6 (stainless)

If the drawing does lock the process, check that the factory is qualified to run it before awarding the job. The evidence is the welding procedure specification (WPS) for that process and the record that qualifies it (WPQR), to ISO 15614-1 for steel or ISO 15614-2 for aluminium.

Welding certifications such as ISO 3834 and EN 1090 are a useful first filter, and on Haizol they're listed on each factory profile in our welding companies factory directory alongside the welding equipment, so they can be checked before quotes are compared

Frequently Asked Questions

Can Aluminium Be MIG Welded?

Aluminium can be welded using MIG, although the setup changes. MIG welding handles aluminium with ER4043 or ER5356 wire, 100% argon shielding and a spool or push-pull gun, and pulse MIG is common on thicker production parts. For thin or visible aluminium, though, TIG with AC remains the standard.

What Are the Disadvantages of MIG and TIG Welding?

MIG welding produces more spatter, offers less heat control on thin sheet and relies on shielding gas that wind disrupts outdoors, so visible MIG welds often need grinding. TIG welding's drawbacks are the mirror image: it is slow, needs tight fit-up and clean joints, and depends on highly skilled welders, which is why it costs more per foot.

Is MIG or TIG Easier to Learn?

MIG is easier to learn and the usual starting point for beginners, because the machine feeds the wire and the welder mainly controls torch angle and travel speed. TIG, by contrast, needs both hands and a foot pedal working together, and that skill gap shows up in TIG labour rates.

Can MIG and TIG Be Used on the Same Part?

Yes, and on thick work it's common. Thick pipe and hydraulic components often get a TIG root pass for consistent fusion, followed by MIG fill and cap passes for speed. In that case, the welding procedure specification (WPS) must be qualified for that combination of processes.

Is TIG Welding the Same as Arc Welding?

TIG, short for tungsten inert gas welding, is one type of arc welding. Arc welding is the broader family, covering every process that uses an electric arc for heat, including MIG (GMAW), TIG (GTAW), stick (SMAW) and flux-cored (FCAW) welding.

Get Quotes on Welded Parts

With the weld requirements defined, the next step is getting comparable quotes. Submit an RFQ with the CAD files and weld notes through Haizol's custom welding solutions page. Factories quote within 24 hours, 90% of RFQs receive quotes from 8+ verified factories, and each factory profile shows welding equipment and certifications to check before awarding.