TIG Torches: Types, Sizes & How to Choose the Right One
A TIG torch is the business end of every GTAW setup — the handle, tungsten, and gas delivery system that puts the arc exactly where a welder wants it. Choose the right torch and TIG welding feels precise and controllable; choose the wrong one and even a $5,000 power source fights you on every bead. Because torches are sized by amperage, cooling method, and head style, the "right" torch for a pipe shop running 300 amps all day looks nothing like the right torch for thin-gauge stainless food-service work. This guide covers what a TIG torch is, how the numbering system works, where each style earns its keep, and how to match a torch to your machine and your work.
What Is a TIG Torch?
A TIG torch holds the non-consumable tungsten electrode, delivers shielding gas around the arc, and carries welding current from the power source to the weld. Unlike a MIG gun, nothing is fed through it automatically — the torch is a precision holder, and the welder controls everything else. If you are new to the process itself, start with our guide to TIG welding (GTAW) and how it works, then come back here to pick the hardware.
Every TIG torch is built from the same core components:
- Torch body and handle — houses the power cable and gas passage; available in fixed-head, flexible-head, and pencil styles.
- Collet and collet body — grip the tungsten and center it in the gas flow. Sized to the tungsten diameter, typically 0.040 in through 1/8 in.
- Nozzle (cup) — the ceramic alumina or lava cup that directs shielding gas over the weld pool. Cup sizes are numbered in 1/16-in increments of orifice diameter.
- Back cap — seals the rear of the torch and sets how much tungsten stick-out you can run. Long, medium, and stubby caps are available.
- Gas lens (optional) — a screened collet body that smooths gas flow, letting you extend tungsten stick-out for better visibility in corners and tight joints.
Torches follow an industry-standard numbering system that started with Weldcraft and is now used across brands. The number describes the torch family, its amperage class, and its cooling method. A #17 is a 150-amp air-cooled workhorse; a #9 is a compact 125-amp air-cooled torch for tight access; a #26 is a 200-amp air-cooled torch with a larger handle; and a #20 is a 250-amp water-cooled torch that stays small because coolant carries the heat away. Suffix letters matter too: "F" means flexible head, "V" means a gas valve on the torch body for machines without a gas solenoid, and "FV" means both.
What Are TIG Torches Used For?
Any work where weld quality, appearance, or metallurgy matters more than travel speed is TIG torch territory:
- Pipe welding root passes — TIG roots on carbon and stainless process pipe, followed by stick or flux-core fill and cap.
- Stainless steel fabrication — food service, dairy, pharmaceutical, and brewery work where corrosion resistance depends on clean welds.
- Aluminum welding — AC TIG on aluminum tanks, boat hulls, truck bodies, and castings.
- Tool and die repair — precise, low-heat buildup on hardened steels with small-diameter filler.
- Aerospace and motorsports — thin-wall tubing, titanium, and inconel where every weld is inspected.
- Maintenance and repair — one clean process that handles steel, stainless, and aluminum with a filler rod change.
The torch you pick shapes each of these jobs. Pipe welders reach for flex-head torches with gas lenses and stubby kits for open-root work in tight quarters. Aluminum welders need higher-amperage torches — AC welding puts more heat into the tungsten, so a torch that runs 200 amps DC may be limited to roughly 150 amps AC. Production stainless shops run water-cooled torches because a small, cool handle saves operator fatigue over a full shift. Your tungsten choice matters just as much — our tungsten electrode guide breaks down which electrode type pairs with which metal.
How to Choose a TIG Torch
Work through these six decisions in order and the right torch falls out the bottom:
1. Match amperage to your work — with headroom
Size the torch to the amperage you actually weld at, plus 20–30% margin. Running a 150-amp torch at 145 amps all day cooks the head and the power cable. Most fabrication under 3/16 in steel lives happily on a #17; heavy aluminum and thick stainless push you to a #26 or a water-cooled #20.
2. Pick your cooling method
Air-cooled torches are simple and rugged. Water-cooled torches need a coolant circulator but run smaller, lighter, and cooler at high amperage. The comparison table below covers the tradeoffs in detail.
3. Choose the head style
Fixed heads are the most durable. Flexible ("F") heads bend to reach into corners and around pipe. If your power source has no gas solenoid — common on engine drives and older transformer machines — you need a valved ("V") torch to control shielding gas at the handle.
4. Check the connection
Torches terminate in a Dinse-style plug (35 or 50 series), a threaded stud, or a one-piece gas-through-power connector. Verify what your machine takes before ordering, or grab the right adapter with the torch.
5. Standardize your consumables
Collets, collet bodies, cups, and back caps are grouped by torch family — #9/20 parts interchange, as do #17/18/26 parts. Shops that standardize on one family carry half the spare parts. A gas lens kit is the single best upgrade for most torches: better coverage at longer stick-out, which you can pair with the right flow settings from our shielding gas guide.
6. Size the cable
Torch packages come in 12.5-ft and 25-ft lengths. Longer reach means fewer machine moves, but adds resistance and weight. Braided one-piece cables resist kinking; two-piece rubber cables are cheaper to replace.
Air-Cooled vs Water-Cooled TIG Torches
The biggest fork in the road is cooling. Here is how the two styles stack up:
| Air-Cooled | Water-Cooled | |
|---|---|---|
| Typical models | #9, #17, #26 | #20, #18, #24 |
| Amperage range | 125–200 A | 250–350 A |
| Torch size and weight | Larger head, heavier cable for the same amps | Compact and light — coolant does the work |
| Support equipment | None — plug and weld | Requires a coolant circulator and TIG coolant |
| Duty cycle at high amps | Limited; heads get hot fast above 150 A | Excellent; built for production welding |
| Best for | Field work, maintenance, light fabrication | Production shops, heavy aluminum, long weld cycles |
The rule of thumb: if you weld above 200 amps for more than a few minutes at a time, water cooling pays for itself in operator comfort and consumable life. Everyone else is usually better served by the simplicity of air cooling.
TIG Torch FAQs
The numbers identify a torch family with a set amperage rating and cooling method, a system standardized by Weldcraft decades ago. A #17 is a 150-amp air-cooled torch, a #26 is its 200-amp big brother, and a #20 is a 250-amp water-cooled torch. Consumables interchange within families — #17, #18, and #26 torches share cups and collets, as do #9 and #20 torches.
Only if your power source lacks a built-in gas solenoid. Engine-driven welders and many older transformer machines have no way to switch shielding gas on and off, so the torch-mounted valve does that job. If your machine has a gas connection and TIG mode, skip the valve — the machine handles pre-flow and post-flow automatically, which protects the tungsten better.
A gas lens replaces the standard collet body with a layered stainless screen that turns turbulent gas flow into a smooth column. That lets you run tungsten stick-out of 1/2 in or more without losing coverage — a huge help on inside corners, pipe joints, and anywhere you need to see the puddle. For most welders it is the best $20 upgrade available.
Yes — air-cooled torches connect to any compatible power source with the right adapter. The reverse is the problem: a water-cooled torch run without coolant flowing will burn up its power cable in minutes, because the cable is undersized on purpose and depends on coolant for heat removal. Never hot-start a water-cooled torch before the circulator is running.
Match tungsten diameter to amperage, not to the torch: 1/16 in covers roughly 30–120 amps DC, 3/32 in covers 80–200 amps, and 1/8 in handles 200 amps and up. Most torches accept the full range with the right collet and collet body. A 3/32-in 2% lanthanated electrode is the do-everything choice for steel and stainless in a #17 or #26 torch.
Cups crack from heat shock and drops — replace them when you see hairline cracks or discoloration that flakes. Collets lose grip after repeated heating cycles; if the tungsten slips when you tighten the back cap, the collet is done. Back caps and O-rings should be checked whenever porosity shows up mysteriously, because a hardened O-ring pulls air into the gas stream.
Ready to Get Started with TIG Torches?
Midland Tool & Supply has stocked welding equipment for Michigan contractors and fabricators since 1962, and our shelves carry TIG torches and consumables from Miller Weldcraft, Profax, Lincoln Electric, and ESAB. Browse our TIG welding and accessories selection for torch bodies, gas lens kits, cups, and collets, or step back and explore the full welding and cutting catalog. Round out your setup with welding cable, leads, and clamps and arc-rated gear from our welding safety equipment department. Safe torch handling starts with the fundamentals in OSHA's welding, cutting, and brazing safety topic, and welders chasing certifications can find procedure and qualification standards through the American Welding Society. For deeper technique articles, Miller's welding resource library is worth a bookmark. Need help matching a torch to your machine — or want on-site weld testing before a big job? Call us at (877) 446-4352 or stop into a branch; our StockUp program keeps your consumables on your shelf so you never run dry mid-shift.
