What is TIG welding used for?

TIG welding is used for applications requiring high-quality, precise welds: aerospace components, stainless steel pipe and tubing, aluminum fabrication, roll cages, exhaust systems, food-grade equipment, semiconductor tooling, architectural metalwork, and medical devices. Any application where weld appearance, dimensional precision, or metallurgical cleanliness cannot be compromised is a candidate for GTAW.

Is TIG welding harder than MIG welding?

Yes. TIG welding requires both hands — torch in the dominant hand, filler rod in the other — plus real-time foot pedal amperage control, all simultaneously. Most welders need 40–80 hours of deliberate practice to produce consistent, structurally sound TIG welds. MIG welding has a significantly shorter learning curve because wire feeding and amperage are controlled by machine settings rather than manual technique.

What gas do you use for TIG welding?

100% argon is the standard shielding gas for TIG welding on steel, stainless steel, and aluminum. Flow rate is typically 15–25 cubic feet per hour (CFH) depending on cup size and conditions. An argon/helium blend — commonly 75% argon / 25% helium — increases arc heat and improves puddle fluidity on thick aluminum and copper, though at higher cost. Never use CO₂-containing MIG gas (C25) for TIG welding; CO₂ oxidizes the tungsten electrode and contaminates the weld.

Can you TIG weld without filler rod?

Yes. Autogenous TIG welding — welding without adding filler metal — is used on thin sheet metal and precision joints where base metal fusion alone provides adequate strength. Autogenous welding requires very tight joint fit-up (zero gap), clean base material, and careful amperage control to achieve full fusion without adding mass to the joint. It is common in thin-wall stainless tubing, aerospace sheet metal, and instrumentation work.

What is the difference between AC and DC TIG welding?

DC electrode-negative (DCEN) TIG is used for steel, stainless steel, copper, titanium, and most metals. It concentrates heat at the workpiece, produces deep penetration, and preserves the tungsten tip. AC TIG is required for aluminum and magnesium because the electrode-positive half-cycle of the AC wave breaks up the aluminum oxide layer on the base metal surface — a cleaning action that DC cannot provide. Most aluminum TIG welders run on AC.

What tungsten should I use for TIG welding aluminum?

On modern inverter-based AC TIG machines, 2% lanthanated (gold-band) tungsten is the recommended choice for aluminum. It holds its geometry well under AC current, starts reliably, and handles the full AC power range. On older transformer-based sine-wave AC machines, pure tungsten (green band) or zirconiated (white band) are traditional choices that form a stable balled tip under the sine-wave AC cycle.

What filler rod do I use for TIG welding stainless steel?

For welding 304 stainless to 304 stainless, use ER308L filler rod. For 316 stainless (molybdenum-bearing, used in marine and chemical environments), use ER316L. For dissimilar joints between stainless and carbon steel, ER309L is the standard choice. The 'L' suffix indicates low carbon content, which limits chromium carbide precipitation in the heat-affected zone and preserves corrosion resistance.

How do I set up argon flow rate for TIG welding?

A starting point for most TIG applications is 15–20 CFH with a standard #7 or #8 ceramic cup. Larger cups (e.g., #10 or gas lens configurations) allow lower flow rates — sometimes 10–15 CFH — with better coverage. Increase flow rate if porosity appears in the weld or if welding in drafty conditions. Excessive flow (above 25–30 CFH) can create turbulence that actually draws in atmospheric air around the cup edges — more gas is not always better.

How long does it take to learn TIG welding?

Most welders with no prior arc welding experience can produce visually acceptable TIG welds on flat mild steel within 20–40 hours of practice. Consistent code-quality welds on stainless pipe or aluminum require 80–150 hours of deliberate practice. Transitioning from MIG welding to TIG is easier — typically 20–40 hours to develop foot pedal coordination and filler rod technique. TIG welding for beginners is best started on flat mild steel before progressing to aluminum or stainless.

Do I need a foot pedal for TIG welding?

A foot pedal is not strictly required, but it is strongly recommended for most TIG welding. Without amperage modulation, controlling heat on aluminum and thin stainless is significantly more difficult. Hand amptrol (fingertip remote on the torch body) is an alternative when a foot pedal is impractical — positional pipe welding, working in tight areas. For practice on flat mild steel at fixed settings, some beginners start without a pedal to focus on torch control before adding the variable of amperage modulation.

Lincoln Electric TIG Welders Guide | Equipment, Accessories & Setup

Q: What is a gas lens and when should I use one?

A gas lens is a collet body insert that contains a fine stainless mesh, which converts the turbulent argon flow from a standard torch body into a laminar (smooth, layered) stream. Laminar flow provides significantly better shielding coverage with the same or lower gas flow rate, allows longer tungsten extension (useful in tight joints), and reduces porosity on critical materials like titanium and stainless. Gas lenses are inexpensive and are worth fitting as a default on any torch used for stainless or titanium work.

WeldingMart's TIG welder hub brings together the precision arc welding equipment used in aerospace, motorsport fabrication, food-grade manufacturing, and custom metalwork. TIG welding demands more skill than MIG or stick, but it rewards that investment with unmatched arc control, minimal distortion, and clean finished welds that require little to no post-weld cleanup. This hub covers the full TIG ecosystem — AC/DC machines, foot pedals, torches, tungsten electrodes, filler rod, and protective gear — from entry-level setups to fully featured pulse machines used in professional shops.

Understanding TIG Welding

TIG welding — Gas Tungsten Arc Welding (GTAW) — uses a non-consumable tungsten electrode to generate the arc. Unlike MIG, the electrode doesn't melt into the weld. Instead, the welder manually feeds a separate filler rod into the puddle with one hand while controlling the torch with the other — or, for autogenous (fusion) welds on thin material, uses no filler at all. An inert shielding gas (argon, helium, or a blend) protects the tungsten and weld pool from atmospheric contamination throughout the process.

The hallmark of TIG is fine arc control. A foot pedal or thumb control allows the operator to modulate amperage in real time as the puddle changes — essential for welding material of varying thickness, working around tack welds, or feathering into a taper at the end of a run. TIG produces the narrowest heat-affected zone (HAZ) of any common arc process, which is why it's the default for thin stainless, titanium, and heat-sensitive alloys where distortion must be minimized.

Weld quality on TIG is directly proportional to base metal cleanliness. Mill scale, grease, oxide, and moisture cause porosity and tungsten contamination. Grinding, acetone wiping, and thorough drying are standard prep steps, not optional extras.

When to Use TIG Welding

TIG is the standard process wherever weld quality, appearance, or code requirements demand the highest level of control. Key application scenarios:

Application	Material	Thickness Range	Mode
Aerospace structures & tubing	Titanium, Inconel, 4130 chrome-moly	0.040" – 1/4"	DC, often no filler (fusion)
Stainless food/pharma	304L, 316L stainless	0.060" – 3/8"	DC, back-purged root passes
Aluminum fabrication	5052, 6061, 7075 aluminum	0.063" – 1/2"	AC (oxide cleaning action)
Motorsport roll cages	4130, mild steel DOM tubing	0.060" – 3/16"	DC
Exotic alloy repair	Titanium, Hastelloy, Inconel	Varies	DC, controlled atmosphere
Precision thin-sheet stainless	304/316 SS	0.020" – 0.060"	Pulsed DC

TIG is not the right process for high-volume structural steel fabrication, field welding on dirty or coated base metals, or applications where throughput matters more than aesthetics. MIG or flux-cored welding handles those conditions more efficiently.

Key Equipment Categories

AC TIG Machines

AC output is required for aluminum TIG welding. The alternating current provides a cleaning action during the electrode-positive half-cycle that breaks up the aluminum oxide layer, while the electrode-negative half-cycle delivers penetrating heat. Modern AC TIG machines allow independent adjustment of AC frequency and balance. Higher AC frequency (typically adjustable 20–400 Hz) narrows the arc cone for tighter bead profiles on thin aluminum.

DC TIG Machines

DC electrode-negative (DCEN) is standard for TIG welding steel, stainless, titanium, and copper alloys. DCEN concentrates arc heat primarily into the base metal, producing deep penetration with minimal tungsten erosion. Dedicated DC TIG machines are compact and efficient — a natural choice for pipe welding, motorsport fab, and shops that don't weld aluminum. Many also support stick welding (SMAW) for added field versatility.

AC/DC TIG Machines

AC/DC machines handle the full range of weldable metals — aluminum on AC, everything else on DC. Lincoln Electric's Square Wave TIG and Precision TIG series are the benchmark in this category, offering digital AC frequency control, adjustable waveform shape (square, soft square, sine, advanced), and built-in high-frequency arc starts. For shops that weld multiple alloys or need a single machine to serve multiple operators, an AC/DC unit is the standard professional choice.

Pulsed TIG Machines

Pulse TIG alternates between a high peak current and a low background current at an adjustable frequency (from slow manual pulses at 0.5 Hz to hundreds per second). High-speed pulse limits heat input and distortion on thin stainless and titanium. Slow pulse helps welders establish a consistent bead rhythm on pipe without a foot pedal. Advanced inverter machines from Lincoln, Miller, and ESAB offer both low-frequency manual pulse and high-frequency automatic pulse in the same unit.

Choosing the Right TIG Machine

TIG machine selection depends on the primary base metals, the available input power, and how much process control the application demands:

DC only vs. AC/DC: If you never weld aluminum, a DC-only machine is lighter, less expensive, and simpler to operate. If aluminum is part of the mix — even occasionally — the AC/DC capability is worth the premium.
Amperage range: Thin gauge sheet (under 1/8") is typically welded at 60–120A. Material up to 3/8" may require 200–250A on a single pass. Heavy-section TIG or exotic alloys with high thermal conductivity (copper) can demand 300A+ or preheat procedures.
HF arc start vs. lift arc: High-frequency (HF) non-contact arc start is standard for precision work — it prevents tungsten contamination of the weld pool. Lift arc (touching and lifting the tungsten) is used where HF could interfere with sensitive electronics nearby.
Pulse capability: For stainless or titanium work where heat input must be controlled, ensure the machine offers true pulse (adjustable peak/background amps, frequency, and duty cycle) — not just a simple on/off pulsed output.
Input voltage: Most professional AC/DC TIG machines require 240V single-phase or three-phase. Compact DC machines often accept 120/240V auto-sensing input.
Foot pedal vs. thumb control: Foot pedals offer the most natural feel for bench and shop work. Thumb controls on the torch body are preferred in confined spaces, overhead positions, or when the operator needs both feet on scaffolding.

Brands We Carry

WeldingMart is an authorized Lincoln Electric Preferred Dealer. Lincoln's TIG lineup — the Square Wave TIG 200, Square Wave TIG 300, and Precision TIG series — represents some of the most capable AC/DC inverter machines available at each price tier. Lincoln's dynasty of precision TIG technology is backed by accessible field service and genuine replacement parts through WeldingMart.

Miller Electric's Dynasty and Maxstar series are strong alternatives for shops already standardized on Miller infrastructure. The Dynasty 280 is a particularly capable machine for mixed-alloy environments.

ESAB offers the Rebel TIG series for portable DC work and the Heliarc line for heavier production TIG. ESAB's inverter designs are widely used in European-standard fabrication environments.

For orbital welding and automated applications, Lincoln Electric's advanced process machines and MK Products' orbital TIG heads are available through WeldingMart's commercial channel.

Consumables & Accessories

Tungsten Electrodes

Tungsten selection is critical. Pure (green band) tungsten suits AC aluminum work on older transformer machines. Modern inverter AC machines perform better with ceriated (grey) or lanthanated (gold/black) tungsten, which holds a sharper point through the AC cycle. For DC work on steel and stainless, 2% ceriated (grey) tungsten ground to a sharp point is the standard recommendation. Thoriated 2% (red) is also common but mildly radioactive — ceriated is preferred in enclosed environments.

TIG Filler Rod

Common filler classifications: ER70S-2 and ER80S-D2 for mild and low-alloy steel; ER308L, ER309L, and ER316L for stainless; ER4043 and ER5356 for aluminum; ERTi-2 and ERTi-5 for titanium grades 2 and 5. Filler rod is sold in 36" cut lengths in diameters from 1/16" through 3/16". Match filler diameter to base material thickness — oversized rod chills the puddle; undersized rod creates excessive heat cycling.

TIG Torches

Air-cooled TIG torches (17, 26 series) handle most shop applications up to 150–200A. Water-cooled torches (20, 18, 9 series) are required for sustained high-amperage work or confined-joint ergonomics. Torch body, back cap, collet, collet body, nozzle, and gas lens are all serviceable components. Gas lenses improve shielding coverage dramatically and are highly recommended for titanium and aluminum work.

Shielding Gas & Back Purging

100% argon is standard for TIG on all common metals. Helium additions (25–75%) increase arc voltage and heat input for copper or thick aluminum, but at higher cost. For stainless root passes, back-purging with argon through the pipe bore prevents sugaring (oxidation on the root side) — dedicated purge bladder systems and purge monitors are stocked for this purpose.

Protective Gear

Minimum shade 10 lens is required for TIG; shade 12–13 is common at higher amperages. Auto-darkening helmets with fast switching speeds are preferred since TIG requires precise tungsten positioning before arc start. TIG gloves are thinner than MIG gloves to maintain filler rod dexterity. Leather or FR cotton sleeves, jackets, and foot protection complete the PPE kit.

Safety Basics

TIG welding produces significant UV and IR radiation — arc eye can occur from even brief unprotected exposure. Always verify the lens shade rating before striking an arc, and never allow bystanders to look at the arc unprotected. High-frequency (HF) arc starters can interfere with pacemakers and sensitive electronic equipment; check with the machine manufacturer's guidelines and keep bystanders at an appropriate distance.

Shielding gas presents an asphyxiation hazard in enclosed spaces — argon is heavier than air and accumulates at floor level. Ensure adequate ventilation, and never use shielding gas cylinders without a properly rated regulator and hose. TIG fume volumes are lower than MIG but not negligible, especially when welding chromium-containing alloys (stainless, Inconel) or surface-coated metals. Local exhaust ventilation at the source is the preferred control method, supplemented by respiratory protection when LEV is insufficient.

FAQs

Why is TIG welding harder to learn than MIG?

TIG requires the welder to simultaneously control torch angle, arc length, filler rod rhythm, and foot pedal amperage — four independent variables — while watching a small, fast-moving puddle. MIG automates the wire feed and runs at a fixed voltage, leaving the operator to manage only travel speed and gun angle. The TIG learning curve is steeper, but the resulting process control is unmatched.

Can I TIG weld aluminum with a DC machine?

Not effectively. Aluminum's oxide layer melts at roughly 3,700°F — far above the base metal's 1,200°F melting point. DC polarity cannot break up this oxide. AC current provides the oxide-cleaning half-cycle necessary for consistent aluminum TIG fusion. AC output is the standard and correct solution for aluminum TIG.

What tungsten should I use for stainless steel?

For DC TIG on stainless, 2% ceriated (grey band) or 2% lanthanated (gold or black band) tungsten ground to a sharp point is the standard recommendation. Grind the taper to 2–3× the tungsten diameter with a small flat on the tip to prevent cracking. Grind marks should run lengthwise along the tungsten for best arc stability.

Do I need a water-cooled torch, or is air-cooled adequate?

For most shop TIG work at 200A or below with reasonable inter-pass rest time, an air-cooled torch is adequate. If you're running sustained high-amperage passes (200A+ for extended periods), welding in a confined joint where you need a smaller torch body, or performing production work with minimal downtime, a water-cooled torch connected to a water cooler will significantly extend torch life and improve comfort.

What is a gas lens and when should I use one?

A gas lens replaces the standard collet body inside the torch. It contains a diffuser screen that converts the turbulent argon flow into a smooth, laminar column of shielding gas. This dramatically improves gas coverage — especially when using larger cup diameters — and allows the tungsten to extend further from the cup without losing shielding. Gas lenses are standard practice for titanium welding (where contamination causes immediate failure) and strongly recommended for stainless, aluminum, and any application requiring consistent, clean weld appearance.

How do I prevent tungsten contamination?

Contamination usually results from dipping the tungsten into the weld pool, touching it with the filler rod, or insufficient post-weld gas coverage. A contaminated tungsten will show a balled or discolored tip — break off the contaminated section, re-grind, and start fresh. Set pre-flow to 0.5–1s and post-flow to 5–15s depending on amperage.

What shielding gas flow rate should I use for TIG?

Standard argon flow is typically 10–20 CFH depending on cup diameter and ambient air movement. Excessive flow causes turbulence that entrains atmospheric air — more is not always better. In drafty environments, use a windscreen or increase cup diameter rather than simply cranking the flow rate.

Can I use my TIG machine for stick welding?

Most AC/DC TIG machines include a stick (SMAW) output. DC TIG machines commonly double as DC stick machines — connect a stinger and electrode holder, select stick on the machine, and weld. The output curve differs slightly from a dedicated stick machine, but for general maintenance stick welding the performance is fully adequate.

Browse Our TIG Welder Collection

Explore WeldingMart's full TIG welding lineup:

Lincoln TIG Welders — Lincoln Electric's full range of AC/DC and DC TIG machines
TIG Welders — Lincoln Preferred Dealer — authorized Lincoln Electric TIG machines and packages
TIG Torches — air-cooled and water-cooled torches, bodies, and consumable parts
TIG Consumables — tungsten, collets, gas lenses, nozzles, and back caps
TIG Filler Rod — ER70S-2, ER308L, ER4043, ERTi and all common TIG filler alloys
TIG Welding Supplies — foot pedals, water coolers, and ancillary TIG equipment
Used TIG Welders — inspected and reconditioned TIG machines