The debate between plasma vs laser as to the ideal for metal cutting equipment is hot and constant. Plasma cutting systems have been successful in taking over many operations where oxyfuel was essential, back in the day. Now, with more options regarding laser cutting equipment, many might believe the same change is happening again.
The truth is that, even though plasma has found a place and is getting bigger, decades later oxyfuel still is in use. So, this led some fellows to believe that laser is not going to override plasma, but both technologies are going to coexist and eventually, they might work in collaboration.
So, the scope of this article is to see clearly the differences between the two processes and to state the pros and cons of each one regarding quality, speed, materials, costs, setup, and maintenance. That being said, let’s get started.
Differences between plasma cutting and laser cutting
Plasma cutting and laser cutting are both widely used cutting methods that use heat to melt or vaporize the material being cut. However, the working principle is a key difference between the two processes.
Plasma cutting uses a high-temperature plasma arc to melt or vaporize the material being cut. The plasma arc is created by passing an electric current through a gas, such as argon or nitrogen. Plasma cutting is typically used for cutting thicker materials, such as steel and aluminum.
Laser cutting uses a high-powered laser beam to melt or vaporize the material being cut. The laser beam is focused through a lens to a very small point, which creates a very narrow and precise cut. Laser cutting is typically used for cutting thin materials, such as sheet metal, plastic, and wood.
But now, let’s get more into detail by evaluating the two processes in five key factors, starting with quality.
Plasma vs Laser Cutting: Quality
The quality of the cut can vary significantly depending on the specific application.
Plasma cutting uses a high-speed jet of plasma to melt or vaporize the metal. Plasma cutting is often used for thicker materials or for cutting materials that are difficult by other cutting processes, such as stainless steel or galvanized metal. The plasma arc causes a 0.5-1.5-degree angle at the vertical cross-section, and often leaves a rougher edge and burrs, which can be a problem in very precise manufacturing. The quality of the cut is typically good, but not as good as laser cutting.
Laser cutting uses a focused beam of light to melt or vaporize the metal, creating a clean, precise cut. Laser cutting is often used for intricate cuts or for cutting thin materials. The quality of the cut is typically very good, with a positioning accuracy of 0.05 mm and a repositioning accuracy of 0.02 mm, leaving smooth edges and little to no burrs.
A reduction in the heat produced in the cutting also contributes to the good quality of the laser systems, because there is less warping in the metal sheets.
In general, laser cutting is a more precise method of cutting metal, making it possible to achieve very intricated cuts. So, we could say that, regarding quality, laser cutting is a winner. But that affirmation only would apply to thinner metals, because the upper limit for a laser cutting system usually is around 20 mm (about 0.79 in), and it can reach 25 mm (about 0.98 in) in some very expensive equipment. Above that thickness there would not be a comparison possible regarding quality.
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Plasma vs Laser Cutting: Speed
Laser cutting is generally faster than plasma cutting, especially for thin materials. However, plasma cutting can be faster for thicker materials. So, in this regard, we could say that there is a tie between the two processes. Only based on your specific needs, you might define what process would serve you better.
Here is a table that summarizes the average speed of laser cutting and plasma cutting for different materials:
| Material | Laser Cutting Speed | Plasma Cutting Speed |
|---|---|---|
| Thin metal (<1/8" thick) | Up to 100 inches per minute | Up to 50 inches per minute |
| Thick metal (1/8"-1/2" thick) | Up to 50 inches per minute | Up to 25 inches per minute |
| Very thick metal (>1/2" thick) | Up to 25 inches per minute | Up to 10 inches per minute |
It is important to note that the speed of both laser and plasma cutting can also be affected by the material being cut, the power of the laser or plasma cutter, and the settings in use. So, the numbers here are just average.
In general, laser cutting is a good choice for applications where speed is important while plasma cutting is a good choice for applications where cost is important.
Plasma vs Laser Cutting: Materials (Types and thickness)
Since this article is a comparison between plasma and laser when it comes to metal cutting, with materials we mean the different metals that can be cut with each process.
Because plasma cutters use high-velocity ionized gas to create a flame, they can cut any electrically conductive metal, such as steel, aluminum, and stainless steel. However, plasma cutting is not effective for cutting materials that are highly reflective, such as copper or brass. Also, since the material must be electrically conductive to react to the ionized gas coming from the torch, non-conductive materials or poorly conductive metals like manganese, lead, tungsten, and tin cannot be cut with plasma.
Laser cutting can be used to cut a wider variety of materials than plasma cutting. In addition to conductive metals like steel and titanium, laser cutting can be used to cut non-conductive or poorly conductive materials, such manganese, chromium, nickel, cobalt, or lead. Laser cutting is also effective for cutting materials that are highly reflective, such as copper or brass.
Here is a table that summarizes the materials that can be cut by plasma cutting and laser cutting:
| Material | Plasma Cutting | Laser Cutting |
|---|---|---|
| Steel | Yes | Yes |
| Stainless steel | Yes | Yes |
| Mild steel | Yes | Yes |
| Carbon steel | Yes | Yes |
| Expanded steel | Yes | Yes |
| Aluminum | Yes | Yes |
| Copper | No | Yes |
| Brass | No | Yes |
| Manganese | No | Yes |
| Chromium | No | Yes |
| Nickel | No | Yes |
| Cobalt | No | Yes |
| Tungsten | No | Yes |
| Lead | No | Yes |
Now, regarding thicknesses, the situation is exactly the opposite. Laser cutting is ideal for thinner metals, while plasma can cut through thicker materials.
Basically, the common thickness range for a laser cutting system is 6 mm (about ¼ in) and the upper cutting limit, for the most advanced power sources would be 20 mm (about 0.79 in).
In the case of plasma cutting systems, the common thickness range is about 25 mm (about 1 in), and the upper cutting limit would be 50 mm (about 2 in).
So, summarizing this point regarding the types and thickness of the metals to be cut, it can be said that laser provides a wider range of materials, while plasma is able to reach a wider thickness.
Most fabrication companies cut the same metals time and again, because they are the materials needed for their production. Use the cutting system ideal for your respective type and thickness.
Plasma vs Laser Cutting: Setup and Maintenance
Plasma cutting and laser cutting have quite different setup and maintenance requirements. Since this refers to the time and money you need to dedicate to the cutting system once you have got it in place, it is especially important that you pay attention to this point. Let´s start with plasma.
Plasma cutting system setup
In a few words, plasma cutting is generally easier to set up and maintain than laser cutting. Plasma cutters typically require less specialized training to operate, and they are less sensitive to environmental conditions.
However, plasma cutters can produce more fumes and sparks than laser cutters, so they require more careful attention to safety. Depending on the conditions of the plant, a fume extraction system might need to be set in place too.
Noise is another side of plasma cutting. Every industrial plant has a lot of noise, but the plasma cutting process is going to add to that. So, make sure you are following the country’s regulations regarding how to protect the operators from excessive noise. That is something that you also need to plan.
Usually, cutting is the starting point of the production process. Once the material is cut, it needs to undergo other processes until is a product ready for market. The exact location of the plasma cutting system within the plant is key to keeping materials moving to the minimum and using the space in the most efficient way.
Every plasma cutting system requires air, gases and electricity to perform. Make sure that you meet the plasma manufacturer’s requirements in these key factors. The purity of the air is decisive in reaching a top-notch cut quality. Investing in a good set of hoses would be essential to avoid gas leaks that could be dangerous and diminish the performance of the power source. Having a steady electrical current all day long (especially if your plant works 3 shifts) is fundamental to achieving excellent cut quality. If your power supply is “dirty” or not reliable, make sure a qualified electrician installs voltage stabilizers or voltage drop compensators to counteract current fluctuations.
Plasma cutting system maintenance
Like any other equipment, plasma cutting systems require maintenance. Only waiting for the system to fail could lead to costly repairs and bottle necks in production. The best-case scenario for a long lasting and finely tuned plasma cutting system is to make a maintenance routine.
The individual components a plasma cutting system is made of might have different maintenance needs. Consult each manufacturer’s user manual to determine what to do with each one. Hypertherm has made a check list that can be useful to keep your plasma cutting system up and running at all times. Basically, it recommends checking:
- Clean the torch body
- Clean the torch leads
- Clean out the power supply
- Check torch-cooling components
- Check water quality
- Check plasma
- Clean machine components (rails, gears, racks, and such)
- Level and align rails
- Align and adjust gears and bearings
- Check the squareness of the torch with respect to the table and workpiece
- Check torch-mounting device
- Check safety limits
- Tune the drive motors and control
If you want to consult this list, read the article Plasma cutting machine maintenance, from Hypertherm.
Laser cutting system setup
Laser cutting is generally more complex to set up and maintain than plasma cutting. Laser cutters require specialized training to operate, and they are more sensitive to environmental conditions, such as dust and humidity.
There are a variety of laser cutting systems. Many of them are enclosed in cabins. If that is the case, having enough room and the ideal location in the plant is paramount.
It is known that laser cutting consumes way more energy than plasma. Make sure to follow the laser manufacturer’s instructions regarding electrical current. This setting must be handled by a specialist in the area.
Laser cutting system maintenance
Most experts recommend performing a whole revision of the equipment once a year. Also, a monthly and weekly maintenance routine must be set in place.
Weather also will play a role in the maintenance of a laser cutting system. In some countries temperatures can drop below 0 centigrade, which can lead to malfunctioning of the system. It is imperative the use of anti-freeze liquid in the coolant component to ensure the normal operation in such extreme climate.
One key aspect of the maintenance is the optics. Make sure that an expert keeps the optics free of dust with acetone or alcohol. This should be done every 10-40 hours of use, depending on the material being cut.
Other important areas to take into consideration for maintenance would be the fan unit, the compressor, the water chiller, etc. Make sure that the whole laser cutting system is properly lubricated and free from dust.
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Plasma vs Laser Cutting: Costs
This is probably the point that brings us home. The cost of a plasma and a laser cutting system can vary depending on the size and complexity of the cut to be made, the type of equipment being used, and the cost of consumables.
Plasma cutting is generally by far less expensive than laser cutting. The initial cost of a plasma cutter is typically lower than the initial cost of a laser cutter. While a whole plasma cutting system might cost around $20,000-30,000 for a medium-duty operation, a laser cutting system of similar proportion might cost $50,000-100,000. Of course, these are very rough numbers, and each case must be seen independently, but you get the gist: laser can cost way more than a plasma cutting system.
The cost of consumables, such as plasma gas and cutting tips, is also lower for plasma cutting than the ones used for laser cutting, such as laser cutting fluid and cutting nozzles.
Wrapping up
The best process for you between plasma and laser will depend on your specific needs. If you need to cut thin materials with a high degree of precision, and you have the budget for it, then laser cutting is the way to go. If you need to cut thicker materials at a fast speed, with a lower initial cost, then plasma cutting is the best option.
Here is a basic table that summarizes the key differences between plasma cutting and laser cutting:
| Feature | Plasma cutting | Laser cutting |
|---|---|---|
| Cutting method | Melts or vaporizes material with a plasma arc | Melts or vaporizes material with a laser beam |
| Metals compatibility | Only conductive metals | Conductive and non-conductive metals |
| Material thickness | Thick materials (steel, aluminum) | Thin materials (sheet metal) |
| Cut quality | Good precision | Excellent precision |
| Cost | Less expensive | More expensive |
| Speed | Slower | Faster |
| Versatility | Less versatile | More versatile |
Let us help you to decide
Getting a plasma or a laser cutting system is a long-term decision. You don’t want to miss the spot there. Ultimately, the best way to decide which method is right for you is to consult with a professional who can help you assess your specific needs.
We have decades of experience helping companies to set in place cutting solutions. Let us know what your needs are, and we will assess you with the ideal equipment for your company.
