Plasma Cutting vs Laser Cutting: The Differences Explained

The evolution of laser cutting technology has significantly reshaped the metal fabrication landscape. Historically, laser cutting dominated thin sheet processing below 10mm, while plasma cutting held a clear advantage in the 30-50mm thickness range due to its superior speed. However, the advent of multi-kilowatt lasers, particularly the widespread adoption of 60kW systems, has dramatically expanded laser cutting capabilities into medium and thick plate applications.

This technological leap has precipitated a marked decline in the plasma cutting market, with laser systems gradually supplanting plasma in numerous application scenarios. The rapid ascendancy of laser cutting can be attributed to two primary factors: the maturation of high-power fiber laser technology and the burgeoning demand from industries such as steel construction, shipbuilding, aerospace, and nuclear power, which require efficient, high-precision thick plate processing.

The industry’s enthusiasm for multi-kilowatt lasers has been relentless, swiftly permeating the laser sector. However, this trend has not been without its detractors, particularly regarding the recently introduced 60kW laser cutting machines, which have sparked considerable debate among industry professionals.

Contrary to initial skepticism, the market demand for 60kW laser cutting systems has surpassed available supply within a remarkably short timeframe of less than six months. Notably, the steel construction sector has demonstrated a strong preference for these ultra-high-power laser cutters, repeatedly investing in them to replace plasma cutting systems. This trend appears to contradict earlier doubts and underscores the transformative potential of ultra-high-power lasers in metal cutting processes.

The impact of these advanced laser systems extends far beyond traditional process replacement, offering new possibilities in application scenarios and fundamentally altering the landscape of metal fabrication. As the technology continues to evolve, it promises to unlock further efficiencies and capabilities in thick plate processing across various industrial sectors.

Replacement of Plasma Cutting by Laser

The replacement of plasma cutting by laser technology is accelerating.

Even before the widespread adoption of laser cutting, plasma cutting was the most mature process in metalworking. It utilized the heat from a high-temperature plasma arc to locally melt the metal at the cut, and the momentum of the high-speed plasma was used to eject the molten metal, forming a cut. Plasma cutting was known for its reasonable quality and cost. At that time, plasma cutting was still widely used in the thin and medium plate segments because of its fast cutting speed and smooth kerf.

However, with the emergence of laser cutting, it began to impact plasma cutting to a certain extent. In the thin plate cutting realm, kilowatt-level fiber lasers have an absolute advantage over plasma cutting in terms of quality and efficiency. Their high precision, narrow kerf, minimal heat-affected zone, burr-free edges, and fast cutting speed have made them the preferred choice in this field. In contrast, the disadvantages of plasma cutting have become increasingly apparent.

To counteract the impact of laser cutting, equipment manufacturers have developed more refined plasma cutting machinery to address issues such as rough cut surfaces and poor perpendicularity. By reducing the nozzle aperture size, a highly compressed arc is created, significantly increasing current density to achieve higher cutting precision and surface finish. Nevertheless, plasma cutting in the thin plate domain still cannot compete with laser cutting in terms of processing efficiency, precision, and environmental friendliness.

As the thickness of the materials processed increased, kilowatt-level laser cutting also faced challenges. In the 30-50mm medium and thick plate segment, the cutting speed of laser cutting was significantly lower than that of precision plasma cutting machines, which maintained their position in this domain.

By 2020, the advent of ten-kilowatt laser cutting technology had injected new life into metal processing, aiding in the transformation and upgrading of traditional industries. At that time, laser cutting entered the ten-kilowatt era and initiated a second round of challenges against plasma, fiercely contesting the vast plasma cutting market.

For carbon steel/stainless steel up to 20mm thick, a 20kW laser cutting system surpasses the efficiency of a 300A plasma cutter. However, the initial purchase cost of laser cutting is significantly higher than that of plasma cutting, leaving users wavering between the two options. It was still too early to discuss a full replacement.

By 2022, the widespread adoption of 30kW laser technology truly began to shake the dominant position of plasma cutting, especially impacting the mid-to-thick plate market.

In 2023, the rapid advancement of domestic ultra-high-power fiber laser technology led to the emergence of 60kW lasers, which truly broke through the limitations on cutting thickness and once again challenged plasma cutting.

In terms of cutting efficiency and quality, 60kW laser cutting now has the capability to completely replace plasma cutting. Currently, laser cutting and plasma cutting are evenly matched in terms of overall economic benefits, each dominating half of the market. Ultra-high-power laser cutting reveals an extremely broad application prospect.

Fiber Laser Cutting vs Plasma Cutting

In recent years, laser cutting applications have experienced exponential growth, driven by evolving demands in downstream industries and the declining costs of high-power laser systems. This surge is particularly evident in precision manufacturing sectors, where the technology’s capabilities align with increasingly stringent production requirements.

While plasma cutting remains a viable option for thicker materials, it faces limitations when processing sheet metal below 6mm thickness, especially for applications demanding high cutting accuracy. The intense heat generated during plasma cutting can lead to thermal distortion and edge deformation, compromising the dimensional stability of thin workpieces.

Conversely, laser cutting has emerged as the preferred method for a wide range of materials, showcasing distinct process advantages. Its precision and versatility are particularly beneficial when working with high-melting-point materials, heat-resistant alloys, and superhard alloys. The focused laser beam allows for minimal heat-affected zones, resulting in cleaner cuts and reduced material distortion. Moreover, laser cutting excels in processing semiconductor materials, non-metallic substrates, and advanced composite materials, offering unparalleled accuracy and edge quality. This technology’s ability to handle diverse materials with high precision has positioned it as a cornerstone in modern manufacturing processes, from aerospace components to microelectronics.

1. Comparison between fiber laser cutting and plasma cutting

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.

2. Advantages of fiber laser cutting over plasma cutting

3. High power laser cutting over plasma cutting

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.

See also:

• High-Power Laser Cutting Machines(10,000W+): What You Should Know?
• High Power Laser Cutter: Is It a Future Trend?
• Choosing High-Power Fiber Lasers: A Comprehensive Guide

Advantages of high power fiber laser cutting over plasma cutting

4. 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

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.

1. 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.

2. 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

2. The cutting slot comparison for laser cutting and plasma cutting

3. Oxygen plasma consumable life.

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.

Working Principle of Plasma & Laser Cutting

1. 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.

See also:

• Plasma Cutting Machine: The Ultimate Guide

2. 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.

See also:

• The Ultimate Guide to Fiber Laser Cutting Machine

Application of Plasma & Laser Cutting

Plasma cutting is a versatile process suitable for a wide range of metal materials, particularly excelling in cutting medium to thick plates. Its advantages include rapid cutting speeds, narrow kerf widths, minimal heat-affected zones (HAZ), reduced workpiece distortion, and cost-effective operation. The process utilizes a high-temperature plasma arc to melt and expel material, enabling efficient cutting of conductive metals.

However, plasma cutting does have limitations. It typically produces a slight bevel angle of 0.5-1.5 degrees on the cut edge, which may require secondary processing for precision applications. Additionally, the high-temperature plasma can induce localized hardening at the cut surface, potentially affecting material properties in critical areas.

Laser cutting, conversely, is optimized for thin to medium-thickness plates and boasts exceptional versatility in material compatibility. It can effectively process metals, non-metals, ceramics, composites, and even specialized materials like glass. The highly focused, intense laser beam enables precise material removal through localized melting, vaporization, or chemical reactions.

The inherent characteristics of laser beams—high directionality, brightness, and power density—translate into numerous advantages for laser cutting. These include extremely fast cutting speeds, superior machining accuracy (often within ±0.1mm), and exceptionally narrow kerf widths (as small as 0.1mm for thin materials). The resulting cut edges are typically of such high quality that they require minimal or no post-processing, streamlining production workflows.

In comparing the two technologies for material cutting applications, laser cutting offers broader material versatility and is particularly advantageous for thin sheet processing. It excels in scenarios requiring high precision, complex geometries, or minimal heat input. Laser systems can also be more easily integrated into automated production lines due to their non-contact nature and precise control.

However, the cost-benefit analysis favors plasma cutting in many industrial scenarios, especially for thicker materials or when ultra-high precision is not critical. Plasma systems generally have lower initial investment costs, reduced operating expenses, and can be more cost-effective for large-scale production of medium to thick plate components.

The choice between plasma and laser cutting ultimately depends on specific application requirements, material types and thicknesses, production volumes, and budget constraints. Many advanced manufacturing facilities employ both technologies to optimize their cutting capabilities across a diverse range of projects and materials.

Advantages and Disadvantages of Plasma & Laser Cutting

1. 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.

2. Plasma cutting advantages and disadvantages

For plasma cutting, it also has its advantages and disadvantages:

Advantages：

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.

Disadvantages：

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.

Conclusion

In this article, we have provided a comprehensive overview of laser cutting and plasma cutting technologies, examining their principles, capabilities, and applications in sheet metal fabrication.

By exploring these cutting-edge methods, we aim to equip you with a deeper understanding of their respective strengths and limitations. This knowledge is crucial for making informed decisions in modern metal fabrication processes.

The choice between plasma cutting and laser cutting ultimately hinges on a complex interplay of factors, including:

1. Production goals: Consider throughput requirements, batch sizes, and material diversity.
2. Cost considerations: Evaluate initial investment, operational expenses, and long-term ROI.
3. Accuracy demands: Assess the required precision, edge quality, and tolerance specifications.
4. Material properties: Analyze thickness ranges, composition, and surface finish requirements.
5. Energy efficiency: Compare power consumption and environmental impact.
6. Automation potential: Examine integration capabilities with Industry 4.0 technologies.

If you find yourself still uncertain about which technology best suits your specific manufacturing needs, we encourage you to reach out to our team of experienced metallurgists and fabrication specialists. Our experts can provide tailored guidance, taking into account your unique production environment, budget constraints, and quality standards to help you make the most advantageous decision for your operations.