Types of Industrial Gas for Welding: Complete Texas Guide
Oxygen, acetylene, argon, CO₂, nitrogen, helium, propane — what each gas does, which welding process needs which gas, and what to ask your Texas supplier.
Oxygen (O₂)
- Purity / Grade
- 99.5% (industrial) to 99.999% (medical)
- Used For
- Oxy-fuel cutting, oxy-acetylene welding, plasma cutting assist gas, combustion enhancement
- Cylinders
- T cylinder (330 cu ft), K cylinder (220 cu ft), R cylinder (80 cu ft)
Most commonly used gas in Texas industrial settings. Essential for all oxy-fuel work. Never use near oil or grease — oxygen accelerates combustion violently.
Acetylene (C₂H₂)
- Purity / Grade
- 99.6% min (commercial grade)
- Used For
- Oxy-acetylene welding, torch cutting, heating, brazing, flame straightening
- Cylinders
- MC (10 cu ft), B (40 cu ft), 145 cu ft standard — stored in acetone-saturated porous material
Do not use above 15 PSI — becomes unstable. Never store or use horizontally. Storage laws in Texas vary by county; check with your local fire marshal for quantities above 300 cu ft.
Argon (Ar)
- Purity / Grade
- 99.997% (welding grade)
- Used For
- TIG welding (all metals), MIG welding stainless and aluminum, plasma cutting shielding
- Cylinders
- T cylinder (330 cu ft), K cylinder (220 cu ft)
Pure argon for TIG on stainless, aluminum, and titanium. For MIG on steel, usually blended with CO₂ (C25: 75% Ar / 25% CO₂ is the most common mix in Texas shops).
Carbon Dioxide (CO₂)
- Purity / Grade
- 99.5% (industrial welding grade)
- Used For
- MIG welding mild steel (short circuit and globular transfer)
- Cylinders
- T cylinder (50 lbs), siphon cylinders for liquid withdrawal
100% CO₂ gives deeper penetration but more spatter than Ar/CO₂ mixes. Popular for high-deposition structural work in Texas construction. Significantly cheaper than argon — important for high-volume shops.
Argon/CO₂ Mixes (C25, C15, C10)
- Purity / Grade
- Argon 99.997%, CO₂ 99.5%
- Used For
- MIG welding mild and low-alloy steel, flux-core welding
- Cylinders
- T cylinder (330 cu ft), K cylinder (220 cu ft)
C25 (75% Ar / 25% CO₂) is the single most common welding shielding gas in Texas shops for mild steel MIG. C15 gives slightly less spatter. C10 for thin gauge. Most independent suppliers stock C25 and C10 as standard.
Nitrogen (N₂)
- Purity / Grade
- 99.998% (welding grade)
- Used For
- Stainless steel purge gas (back purge for TIG root passes), copper brazing, laser cutting assist
- Cylinders
- T cylinder (330 cu ft), liquid dewars for high volume
Essential for stainless steel pipe TIG work where you need an oxygen-free environment at the back of the weld. Liquid nitrogen from independent suppliers in Texas is significantly cheaper per cubic foot than cylinders for high-volume users.
Helium (He)
- Purity / Grade
- 99.995%
- Used For
- TIG welding thick aluminum and copper, added to argon for deep penetration, plasma cutting
- Cylinders
- T cylinder (275 cu ft)
The most expensive industrial gas. Texas pricing is volatile — helium is non-renewable and supply is tight. Used when argon alone doesn't provide enough heat or penetration. He/Ar 75/25 mix is common for heavy aluminum TIG. Not all independent suppliers stock helium — call ahead.
Propane (C₃H₈)
- Purity / Grade
- HD-5 (95% min propane, consumer/industrial grade)
- Used For
- Heating, torch cutting (with oxygen), brazing, HVAC, forklift fuel, roofing
- Cylinders
- 20 lb, 30 lb, 100 lb cylinders; bulk tank delivery
Propane cannot weld steel but is widely used for heating and cutting in Texas construction and agricultural settings. Many independent welding supply distributors in Texas also sell propane. Propane cylinder exchange is distinct from industrial cylinder programs.
Quick Reference: Gas by Welding Process
| Process | Torch/Shield Gas | Fuel / Back Purge |
|---|---|---|
| MIG — Mild Steel | C25 (75Ar/25CO₂) | — |
| MIG — Stainless | 98Ar/2CO₂ or TriMix | — |
| MIG — Aluminum | 100% Argon | — |
| TIG — Stainless | 100% Argon | Nitrogen or Argon purge |
| TIG — Aluminum | 100% Argon or He/Ar | — |
| TIG — Titanium | 100% Argon | Argon purge |
| Oxy-fuel Cutting | O₂ | Acetylene or Propane |
| Oxy-fuel Welding | O₂ | Acetylene |
| Plasma Cutting | O₂ or Air | — |
| Stick (SMAW) | None (flux shielded) | — |
Frequently Asked Questions
What gas do I need for MIG welding mild steel in Texas?
C25 (75% argon / 25% CO₂) is the standard for most Texas shops. For structural work with more spatter acceptable, 100% CO₂ is cheaper. For thin gauge, use C10 or C15.
What gas do I need for TIG welding stainless steel?
Pure argon (99.997%) for the torch. Nitrogen or argon for back purging pipe and tube root passes. Never use CO₂ or mixed gases in a TIG torch.
What is the difference between industrial oxygen and medical oxygen?
Industrial O₂ is 99.5% purity for cutting and welding. Medical O₂ is 99.999% with strict contamination controls for human use. Use industrial grade for all welding and cutting applications in Texas.
Where can I buy industrial gas cylinders in Texas?
WeldIndex lists 188 verified independent suppliers across 125 Texas cities. For MIG/TIG gases, contact local welding supply stores. Avoid propane kiosk exchanges (Blue Rhino, AmeriGas) — they do not carry welding gases.