Looking for the best cutting method for your metal fabrication needs? Look no further than this ultimate guide to laser cutting vs. plasma cutting.
This comprehensive article breaks down the working principles, advantages, and disadvantages of both methods, providing you with all the information you need to make an informed decision.
Whether you’re cutting thin sheets or medium-thick plates, this guide will help you determine which method is best suited for your specific project needs.
With detailed comparisons of factors such as cutting speed, accuracy, and cost, you’ll be able to weigh the pros and cons of each method and make an informed decision.
So, whether you’re a seasoned metal fabricator or just starting out, this guide is a must-read for anyone looking to take their cutting game to the next level.
Working principle of the plasma cutting machine:
A processing method that utilizes high-temperature plasma arc heat, using oxygen or nitrogen as a working gas, to melt and vaporize the incision of a metal part.
The momentum of the high-speed plasma flow is then used to remove the molten metal, resulting in the formation of a slotting seam.
The working principle of the laser cutting machine:
The laser generated by the laser device is transmitted through a series of mirrors and focused on the surface of the workpiece by a focusing lens, causing the hot spot on the workpiece to melt or vaporize and forming a slit.
Simultaneously, auxiliary gas is utilized in the cutting process to remove the slag from the slit, ultimately accomplishing the goal of processing.
Plasma cutting is suitable for cutting all types of metal materials and is mainly used for cutting medium-thick plates. The advantages of plasma cutting include fast cutting speed, narrow cut slots, small heat-affected areas, minimal deformation, and low operating costs.
However, a disadvantage is that it causes a 0.5-1.5 degree angle at the vertical cross-section and hardening of the incision.
Laser cutting, on the other hand, is mainly used for cutting medium-thin plates and has a very wide range of cutting materials including metal, non-metal, ceramics, glass, etc.
Due to the high direction, brightness, and intensity of the laser, it has a fast cutting speed, high machining precision, and narrow cut seams that do not require any further processing.
In conclusion, in terms of material cutting, laser cutting has a wider range of choices than plasma cutting. For cutting thin sheets, laser cutting has a clearer advantage.
However, in terms of cost, plasma cutting is much more economical than laser cutting.
Laser cutting advantages and disadvantages
Compared to traditional cutting methods, a laser cutting machine has several notable advantages:
- Narrow cutting kerfs, allowing for direct welding without grinding of the cutting surface.
- High cutting speed: it can reach 10 m/min for thin sheets, which is faster than plasma cutting.
- Excellent cutting quality: minimal deformation, low surface roughness, and a clean, straight edge.
- High precision: with a positioning accuracy of 0.05 mm and a repositioning accuracy of 0.02 mm.
- Wide range of cutting materials: besides metal, it can also cut wood, plastic, rubber, PVC, leather, textiles, and organic glass.
However, there are also some disadvantages of laser cutting:
- High cost: both the initial investment and ongoing maintenance are more expensive.
- Currently, laser cutting is more cost-effective for thin plates. However, when cutting thick plates, efficiency is low, and it is not recommended unless the quality requirements are high.
Plasma cutting advantages and disadvantages
For plasma cutting, it also has its advantages and disadvantages:
In the process of cutting medium-thick plates, plasma cutting can achieve a high cutting speed, which is much higher than the speed of laser and flame cutting.
Additionally, the initial investment in equipment is lower compared to laser cutting and the maintenance cost is also significantly lower.
The disadvantages of plasma cutting include:
① Poor perpendicularity of the cutting surface, leading to a significant oblique cutting edge on the side.
② Generates more cutting slag which requires removal by grinding, increasing labor costs.
③ Emits harmful dust and arc light during the cutting process. However, underwater plasma cutting can mitigate this issue.
④ High consumption of cutting nozzles in the long-term, leading to high costs.
Fiber laser cutting vs plasma cutting
In recent years, the demand for laser cutting applications has shown signs of rapid growth due to the upgrading of the demand of downstream industries and the decline in the cost of high-power lasers.
However, plasma cutting can be prone to producing significant deformation when cutting sheet metal that is below 6mm and has high cutting accuracy requirements.
On the other hand, laser cutting has clear process advantages, particularly for materials with high melting points, heat-resistant alloys, superhard alloys, semiconductor materials, non-metallic materials, and composite materials.
Comparison between fiber laser cutting and plasma cutting
|Fiber laser cutting||Plasma cutting|
|Principle||A high-power density laser beam is employed to scan the surface of the material, rapidly heating it to temperatures ranging from thousands to tens of thousands of degrees Celsius. |
This causes the material to melt or vaporize, and the melted or vaporized material is then removed from the slit with a high-pressure gas.
|With oxygen or nitrogen as the working gas, a high-temperature and high-speed plasma arc serves as the heat source, locally melting the metal being cut. |
The melted metal is then removed by a high-speed airflow, forming a narrow slit.
|Material||Metal materials, special metal materials and non-metallic materials||Carbon steel, stainless steel, aluminum, copper, cast iron and other metal materials|
|Cutting thickness||Medium thick plate||Medium thin plate|
|Cutting accuracy||Finish machining (within 0.2mm)||Rough machining (within 1mm)|
|Slit width||Very small (0.2 ~ 0.3mm)||Small|
|Heat affected zone||Very small (width 0.1mm)||Small|
|Plate deformation||Very small||Small|
When replacing some punching functions with laser cutting, it may be necessary to purchase a press brake machine to complete the subsequent bending process.
This is a common consideration for customers when purchasing a laser cutting machine.
Advantages of fiber laser cutting over plasma cutting
|Item||Fiber laser cutting||Plasma cutting||Fiber laser advantages|
|Positioning accuracy||0.14mm||0.4mm||High accuracy|
|Section perpendicularity||0.2mm（40mm）||5mm（40mm）||No finishing required|
|Slit width||0.2-1.5mm||2-5mm||Save materials|
|Reserved edge and common edge||3-4mm||10mm||Save materials|
|Heat affected zone||0.1-0.4mm||0.5-2.0mm||Small deformation|
|Section quality||Excellent, less slag hanging||Normal||No grinding required|
|Cutting speed (within 20mm)||Very fast||Normal||High production efficiency|
|Cut a small hole||Diameter depth ratio: 10-20%||Unable to cut hole||Save drilling machine and transfer|
|Beveling||Beveling||Generally not||Saving beveling machine|
|Work environment||Clean||Smoke filled the house||Health and environmental protection|
High power laser
The increasing popularity of high-power lasers has allowed laser cutting equipment to surpass the thickness limit.
Previously, the sales volume of high-power lasers was very low, and the application of laser cutting was restricted by thickness for a long time.
Traditionally, flame cutting was believed to have the broadest range of plate thickness, being suitable for processing thick and extra-thick plates with low accuracy requirements and having obvious speed advantages for plates thicker than 50mm.
Plasma cutting, on the other hand, has an obvious speed advantage in the range of 30-50mm but is not suitable for extremely thin plates (<2mm).
On the other hand, laser cutting, which mostly uses kilowatt-level lasers, has obvious advantages in speed and accuracy for plates below 10mm.
In recent years, with the growing popularity of high-power lasers, laser cutting equipment has slowly infiltrated the medium-thick plate cutting market.
Limit cutting thickness and optimal cutting thickness for a 20kW watt laser cutting machine (mm) are included.
The increase in power results in an increase in cutting thickness and efficiency of the equipment.
According to statistics, the 20kW laser cutting machine has achieved an optimal cutting thickness of 50mm for mild steel and 40mm for stainless steel.
Steel plates are generally categorized as thin plates (< 4mm), medium plates (4-20mm), thick plates (20-60mm), and extra thick plates (> 60mm) based on their thickness.
With a cutting power of 10000 watts, the laser cutting equipment can now cut medium plates and most of the thick plates, expanding its applications to the field of medium plates.
Furthermore, high power lasers also result in improved cutting efficiency.
For instance, the cutting efficiency of a 30000 watt laser cutting machine on a 50mm mild steel plate can be increased by 88% compared to a 20000 watt machine.
- High-Power Laser Cutting Machines(10,000W+): What You Should Know?
- High Power Laser Cutter: Is It a Future Trend?
Advantages of fiber laser cutting over plasma cutting
|Efficiency improvement |
(30kW over 20kW)
Fiber laser cutting cost vs plasma cutting cost
In the field of medium-thick plate cutting, the cost of laser cutting is significantly lower than that of plasma cutting.
Plasma cutting is one of the main methods used in the thick plate field, however, the cost of laser cutting is lower for two reasons:
- Laser cutting equipment and personnel requirements are minimal, reducing the overall fixed costs.
- Laser cutting is more efficient in terms of productivity.
For example, when cutting a 30mm thick carbon steel plate, the operating cost per meter for 12kW laser cutting, 20kW laser cutting, and 300A plasma cutting are 3.05 yuan/meter, 1.32 yuan/meter, and 3.13 yuan/meter respectively.
The 20kW laser cutting method saves 57.8% in operating costs compared to the 300A plasma cutting method, providing a significant cost advantage.
Cost comparison between laser cutting and plasma cutting
|Cost item||Laser cutting (12KW)||Laser cutting (20kW)||Plasma cutting (300A)|
|Vulnerable parts of equipment (yuan / hour)||5||5||70 |
(electrode, nozzle, vortex ring, etc.)
|Oxygen consumption |
|Vulnerable parts of equipment (yuan/hour)||10 (plate thickness > 20mm)||10 (plate thickness > 20mm)||12|
|Handling (1 person) + polishing |
|Fixed cost |
(3 persons + equipment)
|Cutting speed |
(14mm carbon steel)
|Operating cost per meter||65 / 60 / 4m = 0.27 yuan/m||85 / 60 / 6m = 0.24 yuan/m||282 / 60 / 3.4m = 1.38 yuan/m|
|Cutting speed |
(30mm carbon steel)
|Operating cost per meter||75 / 60 / 0.41m = 3.05 yuan/m||95 / 60 / 1.2m = 1.32 yuan/m||282 / 60 / 1.5m = 3.13 yuan/m|
Laser cutting machine vs. plasma cutting machine
According to our previous experience, the comparison between laser cutting machines and plasma cutting machines is as follows:
Laser cutting machines do not cause any damage to the workpiece, whereas plasma cutting machines may result in some damage to the plate, especially if the torch or nozzle of the plasma cutting machine encounters problems during the cutting process.
The laser beam is focused into tiny points, resulting in a narrow cutting slot for the laser cutting machine. In contrast, the plasma cutting machine’s cutting slot is slightly wider.
Laser cutting machines have a faster cutting speed, with some machines capable of reaching speeds of up to 10 meters per minute, compared to plasma cutting machines.
The cutting surface produced by laser cutting machines is smooth and burr-free, resulting in high-quality cuts.
It’s also a non-contact cutting process.
The heat-affected area is minimal, and there is almost no thermal deformation of the workpiece, which eliminates the need for secondary processing and prevents turned-down edges.
However, laser cutting machines have a limited plate thickness and a higher processing cost.
On the other hand, plasma cutting machines can cut a wide range of steel plates, from 6mm to 40mm, with varying models and power.
They have a lower processing cost and require lower operator skill compared to laser cutting machines.
The laser cutting machine has a high precision with a positioning accuracy of 0.05mm and a re-positioning accuracy of 0.02mm, but requires a strict working environment.
On the other hand, while plasma cutting machines may not have the same level of precision as laser cutting machines, they have a low requirement for working environment and mobility, and a wide range of cutting capabilities.
The advantages of a laser cutting machine:
- High cutting precision: The laser cutting machine is highly precise, with a cutting accuracy of 0.05mm and a repositioning accuracy of 0.02mm.
- Fast speed: The cutting speed of the laser cutting machine can reach 10m/min, making it much faster than plasma cutting.
- Minimal sheet deformation: The heat-affected area of the cut is small, and there is almost no thermal deformation of the workpiece. This means the cutting edge is smooth and without burrs.
These advantages make the laser cutting machine suitable for cutting parts with complicated shapes and high precision requirements.
However, the cutting thickness is limited, and typically it is only used for cutting plates under 8mm thick.
The advantages of a plasma cutting machine:
- Wide cutting range: Plasma cutting can cut all metal plates.
- Fast speed and high efficiency: Plasma cutting is fast and efficient.
- Better precision and fineness than NC oxyfuel cutting: Plasma cutting has a higher precision and fineness than NC oxyfuel cutting.
The disadvantage of plasma cutting is that it is difficult to cut thick plates, especially plates over 20mm.
To cut these thicker plates, a higher plasma power is required, which increases the cost of the equipment.
1. Comparison table for laser cutting and plasma cutting
|Laser cutting (CO2 laser 4kW)||Plasma cutting (O2 plasma 230A)|
|Cuttable materials||Metal: carbon steel, low alloy steel, stainless steel, high alloy steel, aluminum, copper alloy etc;|
Nonmetal: ceramics, plastics, rubber, wood, leather, cloth, paper, film etc.
|High alloy steel such as carbon steel, low alloy steel and stainless steel.|
Other non-metallic high viscosity materials (rubber, film, etc.), brittle materials (ceramics, glass, etc.) cannot be processed.
|Max. cutting thickness||25mm(mild steel)||150mm(ss, ms)|
|Thickness < 1||>10,000||Can’t cut|
|> 100||Can’t cut||―|
|Slot width||Narrow||Very wide|
|Around 0.6mm for 16mm mild steel cutting||Around 0.5mm for 16mm mild steel cutting|
|Cutting size precision(cut off deformation)||Very good||Normal|
|Error ±0.15mm||Error 0.5～1mm|
|Advantage||・Capable of high precision machining.||・Portable|
|・There is very little thermal deformation.||・High speed cut-off with low cost|
|Disadvantage||・The time required for drilling holes increases significantly with the increase in plate thickness.|
・The quality of the processed surface is dependent on the state of the material surface.
・Variations in material composition can affect the quality of the cut surface.
|・The electrode and nozzle have a short service life, with two changes needed per day.|
・The cut has a wide width and significant deformation.
・The width and shape of the cut can be altered due to the wear of the nozzle and electrode.
・The cutting process generates a loud noise.
・A large amount of dust is produced.
・The holes have a large diameter (ranging from φ12mm to φ16mm).
・It’s difficult to cut materials that are magnetized.
2. The cutting slot comparison for laser cutting and plasma cutting
3. Oxygen plasma consumable life.
|Cutting method||Type of electrode||The processing of electrodes.||Electrode life||Nozzle life|
|Oxygen plasma cutting.||S-type||Early developed||60 min||45 min|
|F-type||Insert the modified version||120 min||60 min|
|LL-type||Insertion of special metals.||180 min||60 min|
|Water-adding type oxygen plasma cutting||Similar to F-type||Insert the modified version||120 min||150 min|
1 cycle of arc opening/closing, 1 min longevity comparison of endurance tests (Cut off current value: 250A)
4． The relationship between plate thickness and cost.
5． The incision width and cutting precision of various cutting methods.
6． Cutting conditions of various cutting methods.
- Which is better, a laser cutter or a plasma cutter?
The “better” choice between a laser cutter and a plasma cutter depends on the specific application. Laser cutters provide more precision and are ideal for cutting thinner materials. Plasma cutters, on the other hand, can handle thicker materials and operate faster. So, for intricate work, a laser cutter might be preferred, while for heavy-duty cutting, a plasma cutter might be more suitable.
- What is the difference between CO2 laser and plasma cutting?
CO2 laser cutting and plasma cutting both are thermal cutting processes, but they operate quite differently. CO2 laser cutting involves the use of a laser beam to heat and melt the material, providing high precision and clean cuts. Plasma cutting, on the other hand, uses a jet of ionized gas (plasma) to cut through materials. It’s generally faster and can cut thicker materials than a CO2 laser but with less precision.
- Which is better, laser cutting, water jet, or plasma?
Again, the “better” choice depends on the specific application. Laser cutting offers high precision and speed but may be limited by material thickness and type. Water jet cutting can handle a broader range of materials, including heat-sensitive ones, and offers decent precision but at a slower speed. Plasma cutting is the go-to for thicker materials and faster operation but at the cost of precision.
- What cannot be cut with a plasma cutter?
Plasma cutters are limited by material type. They are designed for conducting materials, so non-conductive materials like wood, plastic, and glass cannot be cut using a plasma cutter. Additionally, very thin materials may be damaged by the heat intensity of a plasma cutter.
- What cannot be cut with a laser cutter?
Certain materials should not be cut with a laser cutter due to safety and health concerns, including materials that emit toxic gases when cut, such as PVC and vinyl. Additionally, materials that reflect the laser beam like copper and aluminum can be challenging to cut. Lastly, thick materials may not be suitable for laser cutting due to its limited power penetration.
In the information above, we have provided an overview of both laser cutting and plasma cutting from various perspectives.
By reading this article, it is hoped that you now have a deeper understanding of these two methods of sheet metal cutting.
The decision of whether to use a plasma cutting machine or a laser cutting machine ultimately depends on the production goals, cost factors, and accuracy requirements.
If you are still unsure, you can reach out to us and allow our experts to help guide you in making a decision.