Argon does the unglamorous work at the welding bench. It does not burn and it does not react. It shields the weld pool from the air so the metal sets clean. Whether you run a mobile TIG rig, a small fabrication shop or an industrial line, the argon in your bottle sets how tidy the finished weld looks.
Two questions decide most argon purchases: pure argon or an argon-CO₂ mix, and which bottle size to put on the trolley. This guide covers both, along with how argon works as a shielding gas and how to handle it safely.
How is argon used in welding?
Argon is an inert gas. During welding it flows from the torch and blankets the arc and the molten metal, keeping the oxygen, nitrogen and hydrogen in the air away from the weld. Without that shield the weld picks up porosity, discolouration and weak spots.
- TIG welding runs on pure argon. You get a stable, precise arc and a clean finish on stainless steel, aluminium, copper and other non-ferrous metals.
- MIG welding on steel runs on an argon-CO₂ mix. The CO₂ adds heat and penetration, and the argon keeps the arc smooth and cuts down spatter.
What is Argon Gas?
Odourless, colourless and tasteless, argon makes up 0.93% of the Earth’s atmosphere. Due to the gas being non-flammable, argon makes an ideal option for welding, where temperatures can reach 3,871°C. In addition to not supporting combustion, the gas is non-toxic. However, with its ability to decrease oxygen levels in the air, ventilation is essential when using this for welding.
As an inert gas, argon does not react with other gases, making another great reason to choose this as a shielding gas for your work.
Why Do You Need Shielding Gas for Welding?
The main purpose of shielding gas is to prevent the weld you are applying to the workpiece from being contaminated by the elements in your work environment. Whilst you may ensure that your workplace is free from pollutants, the air contains nitrogen, oxygen and hydrogen, which can cause various issues such as porosity and excess splatter if they contact the molten metal. This could compromise the join, which could prove dangerous when working with life-supporting structures such as bridges, aerospace, and automotive repairs.
Ensuring you are using high-quality TIG or MIG welding gas can instil confidence that your weld will hold when required.
What Makes Argon a Good Welding Gas?
Argon is an inert gas and provides the stability needed for safety when heating metal to high temperatures during the welding process. It also produces a narrower penetration profile which offers a clean and minimal but strong bond between the two workpieces.
As a gas bottle supplier, we offer a CO2/Argon mix for both industrial applications and hobby welding gas.
Pure argon vs argon-CO₂ mix at a glance
| Pure argon | Argon-CO₂ mix | |
|---|---|---|
| Best for | TIG welding | MIG welding |
| Typical metals | Stainless, aluminium, copper, non-ferrous | Mild steel, general fabrication |
| Arc character | Precise, clean, low spatter | Stable arc, good penetration |
| Common blends | 100% argon | 2%, 5%, 12% or 20% CO₂, balance argon |
| Adams Gas bottles | 2L, 10L, 20L, 50L refillable, 0.95L and 220L disposable | 2L, 10L, 20L, 50L refillable, disposable options |
TIG wants pure argon. MIG on steel wants a mix. A light blend around 5% CO₂ gives a cleaner bead on thin steel and suits car-body and hobby work. A heavier blend up to 20% CO₂ drives deeper penetration on thicker structural steel. Our welding gas mixtures guide covers the ratios in detail, and the MIG vs TIG guide explains why the two processes cannot share a bottle.
Pure Argon for TIG Welding
When looking for TIG welding gas, you will require a pure argon gas, which produces a clean weld with no oxidisation. It can significantly increase your welding execution for many reasons;
- It is heavier than air, so it settles over the weld and protects it fully.
- Prevents any burning through of thinner materials.
- Offers a consistent, reliable and narrow arc for a more precise weld.
- It requires less power and voltage during TIG welding and is more affordable than other options.
The only disadvantage to using pure argon versus other inert gasses is that it cannot operate at high voltage, which may mean longer welding times. However, with the excellent quality of argon, it may be worth taking the extra time for a more accurate weld.
Argon/CO2 Mix for MIG Welding
Unlike TIG welding, MIG welding requires a mixture of argon and CO2 gas. Whilst there are many options for MIG welding gas, argon mixed with CO2 offers;
- Fewer splatters and undercuts than you would get with pure CO2, providing a smoother output.
- The arc will be more stable.
- The weld pool will provide deeper penetration.
- The correct mix will give you the right amount of heat for bending and twisting.
Whilst argon 80% / CO2 20% is the best all-around mix for a wider variety of applications, the specific combination depends on the thickness of the weld. A favourable mix for those wishing to weld thinner steel parts, a 5% CO2, 95% Argon mix offers the best option. If you are unsure, feel free to contact us, and our helpful team will be able to advise you on the best mixture.
Argon and Other Gas Mixes
For the process of MIG welding, you can find argon mixed with other gases such as helium in addition to CO2. These are best for stainless steel, carbon, and low-alloy steel welding applications.
Dangers of Argon
As a stable and inert gas, argon is relatively safe in welding due to its non-toxic and non-flammable nature. However, besides the standard precautions required for handling pressurised bottled gas, the biggest hazard is asphyxiation when using this gas.
Argon replaces the oxygen in the air, leading to nausea, headaches, rapid breathing, drowsiness and other symptoms that a decrease in oxygen can produce. To shield yourself from these risks, it is imperative that your workplace is well ventilated and the proper equipment is used. Taking regular breaks away from the area if you are working on a large piece is also advisable.
Argon gas bottle sizes at Adams Gas
We supply argon in two lines.
Disposable bottles. Single-use 0.95L and 220L bottles with an M10×1 RH fitting. They suit occasional jobs, mobile repairs and hobby welders who weld a few times a year. See all disposable argon cylinders, or read the disposable welding gas guide.
Rent-free refillable cylinders. You buy the cylinder once and swap it for a full one when it runs out.
| Cylinder | Typical user | Pure argon | Argon-CO₂ mix |
|---|---|---|---|
| 2L | Hobby TIG, mobile work, tight spaces | 2L pure argon | 5% CO₂ |
| 10L | Regular hobby and light trade | 10L pure argon | 5% or 20% CO₂ |
| 20L | Busy workshops, mobile welders | 20L pure argon | 2%, 5%, 12% or 20% CO₂ |
| 50L | High-volume fabrication | 50L pure argon | 5%, 12% or 20% CO₂ |
Pick the size by how often you weld. A weekend fabricator rarely needs more than a 10L bottle. A workshop welding daily gets better value and fewer swaps from a 20L or 50L. Sites that burn through several 50L cylinders a week can step up to a manifolded argon pack of 9 or 16 cylinders.
Browse the full range: argon gas bottles, TIG welding gas and MIG welding gas.
Rent-free argon: buy the bottle once
Most large gas suppliers rent you the cylinder and bill a standing charge each month, whether you weld or not. With Adams Gas you buy the cylinder outright and pay only for gas when you refill it. You sign no rental contract and pay no monthly charge on a bottle that sits in the corner between jobs.
If you weld seasonally or on and off, that usually costs less across a year. Our rent-free cylinders guide walks through the sums.
Regulators and fittings
A refillable argon cylinder needs a regulator to bring the pressure down to a usable flow. Our 300 bar single-stage argon regulator fits the refillable range. Disposable bottles take the smaller M10 mini regulator.
Where to buy or refill argon welding gas
Order online for delivery, or swap your empty for a full cylinder at a local stockist. The areas we deliver directory shows your nearest option. For advice on sizes, blends or regular deliveries, contact the team.
Run a workshop, hire shop or trade counter? Become an Adams Gas stockist and supply rent-free argon and welding gas to your own customers.
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Argon welding gas FAQ
Is argon gas flammable?
No. Argon is inert, so it does not burn and does not feed a fire. The workshop risk is different: argon displaces oxygen in an enclosed space, so weld with good ventilation.
Can I use pure argon for MIG welding?
Yes for aluminium, where pure argon is the standard MIG gas. For mild steel, an argon-CO₂ mix welds better and costs less, because the CO₂ adds the penetration steel needs.
What is the difference between pure argon and an argon-CO₂ mix?
Pure argon is 100% argon and is the standard for TIG welding and non-ferrous metals. An argon-CO₂ mix carries 2% to 20% CO₂ and is made for MIG welding steel.
What size argon bottle do I need?
A 2L or 10L cylinder covers hobby and light use. A 20L or 50L cylinder suits a workshop that welds most days and wants fewer swaps. Disposable 0.95L and 220L bottles cover occasional jobs.
Are Adams Gas argon cylinders rent-free?
Yes. You buy the refillable cylinder once and pay only for refills. There is no rental contract and no monthly charge.
