Short answer: TIG uses 100% argon (stainless steel, aluminium) · MAG welding of steel uses 100% CO₂ (economical) or an Ar+CO₂ mix such as 80/20 (less spatter, neater weld) · Never use CO₂ for aluminium
Gas selection table by welding job
| Job/material | Recommended gas | Notes |
|---|---|---|
| TIG, stainless steel | Argon 100% | Clean weld bead |
| TIG/MIG, aluminium | Argon 100% | Do not use CO₂ |
| MAG, carbon steel (economical) | CO₂ 100% | More spatter |
| MAG, carbon steel (neat bead) | Ar+CO₂ mixed gas, e.g. 80/20 | Costs more than pure CO₂ |
| MIG, stainless steel | Mixed gas to suit the welding wire spec | Check the wire manufacturer’s specification |
The right mix and flow depend on the job specification, welding wire and welding machine. Confirm with your factory’s welding supervisor.
Safety
- Argon and CO₂ are heavier than air and accumulate in low or confined spaces, causing asphyxiation. Ventilation is required.
- Keep cylinders upright and firmly secured; close the valve after use.
- Use regulators and hoses suited to the gas type.
FAQ
Which gas is used for TIG welding?
Mainly pure argon, suitable for stainless steel, aluminium and copper.
Which gas is used for MAG welding of carbon steel?
100% CO₂ or an argon+CO₂ mixture (a popular mix is Ar 80% / CO₂ 20%). Mixed gas usually gives less spatter and a neater bead, but costs more than pure CO₂.
What is the difference between argon and CO₂?
Argon is an inert gas and does not react with the weld; CO₂ reacts slightly with the molten metal, so it is used mainly for carbon steel.
What gas is used for welding aluminium?
Pure argon. Never use CO₂.
Where can I order welding gas in Chonburi?
Order argon, CO₂ and mixed gases from MUREX Boonlum Oxygen, tel. +66 89 133 9957 or LINE @hgp6435o [confirm cylinder sizes and delivery service]