Find TIG Settings
TIG Welding Settings Reference
| Material | Thickness | Amperage | Tungsten | Filler Rod | Gas Flow | Cup | Polarity |
|---|---|---|---|---|---|---|---|
| Steel (Mild) | 1/16" | 30-50A | 1/16" (2% Th) | ER70S-2 | 15-20 CFH | #5 | DC- |
| 3/32" | 50-80A | 1/16" (2% Th) | ER70S-2 | 15-20 CFH | #6 | DC- | |
| 1/8" | 80-120A | 3/32" (2% Th) | ER70S-2 | 15-25 CFH | #7 | DC- | |
| 3/16" | 120-160A | 3/32" (2% Th) | ER70S-2 or RDS | 20-25 CFH | #8 | DC- | |
| 1/4" | 150-200A | 1/8" (2% Th) | ER70S-2 or RDS | 20-25 CFH | #8 | DC- | |
| 3/8" | 200-250A | 1/8" (2% Th) | ER70S-2 or RDS | 20-30 CFH | #10 | DC- | |
| Stainless Steel | 1/16" | 40-60A | 1/16" (2% Th) | ER308L | 15-20 CFH | #5 | DC- |
| 3/32" | 60-100A | 1/16" (2% Th) | ER308L | 15-20 CFH | #6 | DC- | |
| 1/8" | 100-140A | 3/32" (2% Th) | ER308L | 15-25 CFH | #7 | DC- | |
| 3/16" | 130-180A | 3/32" (2% Th) | ER308L | 20-25 CFH | #8 | DC- | |
| 1/4" | 160-210A | 1/8" (2% Th) | ER308L | 20-25 CFH | #8 | DC- | |
| 3/8" | 210-260A | 1/8" (2% Th) | ER308L or ER316L | 20-30 CFH | #10 | DC- | |
| Aluminum | 1/16" | 50-80A | 1/16" (Pure) | ER4043 | 15-20 CFH | #5 | AC |
| 3/32" | 80-120A | 1/16" (Pure) | ER4043 | 15-20 CFH | #6 | AC | |
| 1/8" | 120-160A | 3/32" (Pure) | ER4043 or ER5356 | 15-25 CFH | #7 | AC | |
| 3/16" | 160-200A | 3/32" (Pure) | ER5356 | 20-25 CFH | #8 | AC | |
| 1/4" | 200-250A | 1/8" (Pure) | ER5356 | 20-25 CFH | #8 | AC | |
| 3/8" | 250-300A | 1/8" (Pure) | ER5356 | 20-30 CFH | #10 | AC | |
| Chromoly (4130) | 1/16" | 35-55A | 1/16" (2% Th) | ER70S-2 | 15-20 CFH | #5 | DC- |
| 3/32" | 55-85A | 1/16" (2% Th) | ER70S-2 | 15-20 CFH | #6 | DC- | |
| 1/8" | 85-130A | 3/32" (2% Th) | ER70S-2 | 15-25 CFH | #7 | DC- | |
| 3/16" | 130-170A | 3/32" (2% Th) | ER70S-2 | 20-25 CFH | #8 | DC- | |
| 1/4" | 160-210A | 1/8" (2% Th) | ER70S-2 | 20-25 CFH | #8 | DC- | |
| 3/8" | 210-260A | 1/8" (2% Th) | ER70S-2 | 20-30 CFH | #10 | DC- |
Th: Thoriated tungsten. CFH: Cubic Feet per Hour (gas flow). Cup: Ceramic cup size (ceramic cups block gas better than stainless). RDS: Rod. Adjust amps ±10% based on travel speed and puddle control.
Making TIG Work for You
The DC vs AC Choice
Steel, stainless, chromoly: DC-. Period. Aluminum: AC. Non-negotiable. DC- puts heat on the work while the tungsten stays cool. You get penetration and stability. AC flips back and forth 60 times a second, and that's what aluminum needs to clean off its oxide layer as you go. Try DC- on aluminum and it won't melt properly. The oxide layer acts like a barrier. AC is your only play.
Picking the Right Tungsten
Pure tungsten (green, no marking): Aluminum's best friend. Lower melting point, easier arc strike, smaller arc cone you can control. Beginners like it. Trade-off: can't handle as much amperage.
2% Thoriated (red): The workhorse for steel, stainless, chromoly. Better arc starting, handles more amps, more stable. One caveat: it's slightly radioactive (thorium). Don't grind it without wet grinding or vacuum extraction. Standard for structural and pipe work.
2% Lanthanated (gold): Non-radioactive alternative to thoriated. Same performance, safer. Used in food processing and clean-room welding. Costs more but worth it if you care about worker safety.
Ceriated (orange): Another non-radioactive option. Similar to thoriated but needs slightly lower amps. Less common but gaining traction.
Size matters. Thin stuff (under 1/8"): 1/16" tungsten. Medium (3/16" to 1/4"): 3/32". Thick (3/8"+): 1/8". Bigger tungsten holds more amps without balling or burning back.
Gas Flow: The Right Amount Matters
Argon shields the puddle and tungsten from oxidation. Too little and you get porosity and contamination. Too much wastes gas and creates turbulence that hurts shielding. Thin material: 15-20 CFH. Medium: 20-25 CFH. Thick: 25-30 CFH. Set it and watch the puddle. If porosity shows up, bump it 2-3 CFH. Use 100% Argon—no CO2 in TIG, it'll destroy your weld.
Filler Rod Matters
Steel: ER70S-2. Deoxidized, low silicon. Works smooth, controls easy.
Stainless: ER308L for 300-series stainless. Low carbon prevents sensitization (grain boundary cracking). ER316L for corrosion-heavy work. Always match the rod to what you're welding.
Aluminum: ER4043 for general work—lower melt point, beginner-friendly. ER5356 for structural and marine—higher strength. Never use ER70S-2 on aluminum. You'll get brittle, junk welds.
Rod size usually matches tungsten size. 1/16" tungsten takes 1/16" rod. 3/32" tungsten takes 3/32" rod. It balances heat and deposition.
Cup Size and Visibility
#4-5 cups: tight spaces, thin sheet. Can barely see. #6-7: most work, good balance of coverage and sight. #8: bigger puddles, more gas. #10: thick material, high amps, puddle's huge. Bigger cup means better shielding but worse visibility. Smaller is better if you can position yourself right.
Pulse Mode and Modern Machines
New TIG machines pulse—cycling between high and low amps. Less heat overall, better puddle control on thin materials and vertical welds, less warping. Great for aluminum and stainless. Balanced AC on newer inverters automatically balances positive and negative cycles, cleaning aluminum better than old square-wave AC.
When Things Go Wrong
Tungsten balling: The end melts and forms a ball. Either you've got the wrong polarity (AC tungsten on DC work or vice versa), too much amperage for the tungsten size, or both. Check polarity. Use the right tungsten. Maybe bump down amps or go bigger on the electrode.
Porosity: Tiny holes in the bead. Gas flow too low, contaminated tungsten (you dipped it in the puddle), or dirty base metal. Turn up the gas. Keep tungsten clean. Clean the steel before you weld.
No penetration: Amps too low or you're traveling too fast. Increase heat or slow down. If material's thick, you might need bigger tungsten and higher amps to get through.
Puddle won't cooperate: Usually underamperage or wrong polarity. Bump the amps or double-check DC- for steel/stainless, AC for aluminum.
Frequently Asked Questions
Pure tungsten (green, no color marking). Not red (thoriated), not gold (lanthanated). Pure tungsten's easier to start and gives you a smaller arc you can control. Thin aluminum: 1/16". Thicker: 3/32". Downside: pure tungsten won't take as much amperage as thoriated, so stay toward the low end of your amp range.
Start at 100A for 1/8" mild steel. Range is 80-120A. Use 3/32" thoriated tungsten (red), ER70S-2 rod, 15-25 CFH Argon, DC- polarity. Adjust 10-15 amps based on how the puddle looks and flows. Higher amps let you travel faster but the puddle gets bigger. Lower amps mean slower travel but tighter control.
Steel, stainless, chromoly: DC-. Aluminum: AC. DC- is deeper and more stable. AC cleans aluminum's oxide layer as it welds. Try DC- on aluminum and it won't fuse. AC is the only option for aluminum.
100% Argon. That's it. Every material—steel, stainless, aluminum, chromoly. Some shops add Helium for extra heat on thick aluminum or stainless, but pure Argon works for everything. Never CO2. CO2 ruins TIG welds—causes porosity and contaminated tungsten.
Thin (under 1/8"): 15-20 CFH. Medium (1/8" to 1/4"): 20-25 CFH. Thick (3/8"+): 25-30 CFH. Too low and you get porosity. Too high wastes gas and creates turbulence that ruins shielding. Watch the puddle. If porosity shows, bump it up 2-3 CFH.
