Plasma cutting is quite an necessary option if you want to make smooth and clean cuts through a variety of metal materials, especially CNC plasma cutter machine which integrates plasma cutter and CNC technology.
However, there are many factors that determines the actual application & working performance of CNC metal plasma cutter machine, among them, the plasma cutting gas is one you must know to guarantee the optimum performance and high-quality results.
two kinds of gases are actually required for plasma cutting: plasma gas – the gas that actually does the cutting – and a shield or secondary gas. The shield gas is the gas that swirls around your torch and consumables to keep everything from overheating. Different kinds of plasma gases are used in CNC plasma cutting systems and the most popular ones today are compressed air, N2 (nitrogen), O2 (oxygen), H35 (argon-hydrogen) and F5 (hydrogen-nitrogen).
Which is the best gas for plasma cutting? Well, it depends on the actual working requirements, such as the material being cut, the cutting quality, the thickness of material, the consumable life and the cost of production.
Plasma Cutter Gas Type
Many different types of plasma gases can be used for plasma cutting, even though, their working performance & application vary much owing to their respective & unique properties.
So, stay here with us to learn the types of plasma cutting gases and their benefits so that to make the best use of cnc plasma cutting machine for the best results.
Compressed Air
Compressed air is the most commonly used gas and the most versatile for lower current plasma cutting and works well for most metals up to 1 inch thick. Compressed air can also be used for gouging plasma on carbon steel.
However, a concern with air plasma is the weldability of the cutting edge. Some nitriding and oxidation of the cutting surface occurs with air plasma; this can cause porosity in the welds. Due to its versatility, good speed and low slag levels, compressed air can be a good option for many companies.
Compressed air is a highly versatile plasma gas which produces top quality cuts on mild and stainless steel as well as aluminium. But, it’s also suitable for plasma extraction on carbon steel. It’s also a low-cost gas as you won’t need to purchase it. However, you still must clean it to remove any particles, moisture or oil mist. You can use compressed air to cut metals with a thickness of up to 1 inch. However, you’ll achieve an oxidized cut area which could affect the weldability of the cut’s edge.
Nitrogen (N2)
Nitrogen is often used for higher current plasma systems and for cutting materials up to 3 inches thick, although for something more than an inch thick consider using argon-hydrogen. It is the best choice if you cut a lot of aluminum and stainless steel and the quality of the cut and the service life of the parts are excellent (more than 1000 starts are normal). Produces excellent quality cuts on most materials.
Oxygen (O2)
Oxygen is used when the highest quality mechanized cuts are desired from 1 to 1/4 inch thick carbon steel. The cut face is smooth and the slag is easy to remove.
plasma cutting with oxygen can also be used on stainless steel and aluminum, but it produces a rougher cut face. Plasma oxygen gas reacts with carbon steel to produce a finer spray of molten metal, each drop having a lower surface tension. This molten spray is more easily ejected from the cut.
The disadvantage of oxygen is the cost of gas and the useful life of consumable parts. However, state-of-the-art oxygen plasma systems use inert gases (such as nitrogen) with oxygen plasma to achieve a similar part life to nitrogen or air systems. These systems can have part life in the 800-1500-start range. The increased costs of consumables and gas are generally offset by a decrease in costly secondary operations to remove slag and straighten beveled parts.
H35 Gas Mixture (Argon-Hydrogen gas mixture)
The F5 gas mixture (5% Hydrogen and 95% Nitrogen) is mainly used for cutting stainless steel. The F5 blend provides fast, oxide-free cuts, however, Hydrogen gas introduces a lot of heat into the material. As a result, more slag formation, with the cut parts generally needing cleaning before proceeding to welding or painting operations. Using F5 gas mixtures can also be expensive. As an alternative, it is worth evaluating the investment in gas mixers.
Argon-Hydrogen Mixture
The argon-hydrogen mix is usually suitable to cut through stainless steel or aluminium. The standard combination of the mix is 65% argon and 35% hydrogen. It offers the maximum cutting capacities and it’s the hottest plasma burning gas. You’ll achieve an excellent and clean cut. The argon-hydrogen mix is required for mechanical cutting of any type of materials which exceed a 3 inches thickness. But, it’s also suitable for plasma gouging on any materials.
We recommend with any new plasma cutting equipment purchased you call your local Gas Experts to give you the best advice for efficient production.
Plasma Cutting Gas Selection Table
| Plasma Gas/ shield Gas | Carbon Steel | Stainless Steel | Aluminum |
| Air/Air | Economical, good cut quality and speed | Economical, good cut quality and speed | Economical, good cut quality and speed |
| Oxygen/Air | Excellent quality/cutting speed, minimal slag | Not recommended | Not recommended |
| Nitrogen(N2)/Carbon Dioxide(CO2) | Excellent part life, satisfactory cut quality, presence of slag | Excellent part life, good cut quality | Excellent part life, good cut quality |
| Nitrogen (N2)2/Air | Excellent part life, satisfactory cut quality, presence of slag | Excellent part life, good cut quality | Excellent part life, good cut quality |
| Argon (Hydrogen/Nitrogen) | Not recommended | Excellent for thickness above ½” | Excellent for thickness above ½ ” |
| F5 mix (Nitrogen/Hydrogen gas mix) | Not recommended | Good cut with excellent cutting speed for thicknesses below 0.375” | Excellent for thickness above ½7” |
Best Gases For Cutting Aluminum?
Many kinds of metal materials can be well applied for plasma cutting, including aluminium, when it comes to plasma gas, thing will be quite different as not all gases work equally good for different materials. Take aluminum for example, Plasma cutting aluminum gas should be taken for the excellent performance:
1. Hydrogen
Hydrogen gas is a good conductor of heat and cools hot, smooth, and shiny surfaces very fast.
*It can be used in cutting light aluminum metals. It’s also cheap and readily available.
*Hydrogen is easy to store and can combine with argon to enhance its heat intensity. Therefore, it’s suitable for cutting thick metal. You only need to get the correct ratio when combining with other gases.
2. Argon hydrogen
Argon hydrogen is a combination of argon and hydrogen gases.
*It’s excellent in producing mighty hot flames capable of cutting thick aluminum plates. It’s also suitable for cutting thick stainless metals.
*It produces a lot of heat, which is ideal for splitting thick sheets of metal.
*It cuts the thickness of more than ½ inch. It should be mixed in a ratio of 35% hydrogen, 65% argon. Argon hydrogen is the hottest burning plasma gas which provides maximum cutting capacity.
*Fair enough, you’ll benefit from hot flames capable of ripping through thick sheets of aluminum. The cuts will emerge cleaner and well finished.
*Argon gas is suitable for plasma marking. For you to enhance heat intensity, you mix the two gases, argon, and hydrogen.
3. Nitrogen
*It’s economical since it’s plenty in the atmosphere.
*It’s not suitable for thick aluminum plates as it’s not capable of producing hot flames that can cut through.
Please feel free to contact JeesunCNC for further detail on the best gas for plasma cutting aluminum, our technical team will provide the very best solution for your CNC plasma cutter table machine at the possible time.
