• Introduction
• What is Laser Cutting?
• Types of Laser Cutters
• What Kinds of Parts are Laser Cut?
• What are the Advantages of Laser Cutting Over Other Cutting Processes?
• What are the Disadvantages of Laser Cutting?
• Takeaway

Laser cutting is an ever-evolving technology that is highly effective in various forms of manufacturing. This cutting method doesn’t suit every manufacturing situation. In many cases, however, it does offer advantages over both traditional cutting methods and similar cutting methods, such as waterjet and thermal cutting.

The effectiveness of laser cutting can be seen in the growth of its use. In 2022, the market value for laser cutting machines was over $5 billion, with an expected cumulative annual growth rate of 7.5% over the next ten years, according to a report by GMI Insights.

Manufacturers, hobbyists, designers, small businesses and technologists can all use laser cutting as a method for cutting, engraving or welding even the most intricate parts and designs. Laser cutting often lends itself to large scale production, but it can be used for both large scale manufacturing runs or smaller scale projects.

In this article, we’ll look at the advantages and disadvantages that laser cutting offers and also at how the process of laser cutting works.

Laser cutting is a process whereby a highly focused beam of light (laser beam) is used to cut a material.

The process that underlays laser cutting is thermal separation. Laser-cutting tools generate laser beams with enough energy that they vaporize or raise the temperature of a material beyond its melting point, causing thermal separation.

Modern lasers use computer-controlled machines to perform accurate, fast and repeatable cuts. Highly skilled and experienced technicians set the path of the laser with the aid of computer numerical control (CNC). The machine then follows the direction via its motion control system to create the desired cuts or designs.

The two basic types of laser cutting machines used in metal fabrication are solid-state and gas-state lasers.

• Solid-state lasers use a solid material, such as an optical fiber, as a medium for generating the laser.
• Gas-state lasers use a gas, like carbon dioxide, as the medium.

In turn, the most popular types of solid-state and gas-state lasers are CO₂ and fiber lasers respectively.

CO2 Lasers

These lasers work by using an electric current to stimulate a mixture of carbon dioxide, helium and nitrogen. Once stimulated, this gas mixture produces light, which is then amplified by a series of reflective devices to produce a laser beam. CO2 laser machines emit beams with a 10.6μm wavelength.

With laser beams of this wavelength, they are effective at processing or cutting non-metallic materials as well as metallic materials. These laser machines can also process thicker (>5mm) non-metallic materials faster than fiber laser machines and with a better finish.

One of the downsides to CO2 laser machines is that they require more maintenance. These machines have more internal parts, such as mirrors or electrodes, that are subject to wear, erosion or plating. These parts may need maintenance, replacement or correction (to the alignment, for example) to maintain a high level of output.

Fig. 1: CO2 Laser Cutting Machine

Fiber Lasers

The energy beams in fiber lasers are produced by laser diodes and optical fiber treated with rare earth elements like erbium (Er). Fiber lasers offer certain advantages over other types of laser cutters and are perhaps the most commonly used laser-cutting tool for industrial applications.

• The energy beams from fiber lasers are of the highest quality and focus, meaning they hit a smaller proportion of the sheet material. This makes it possible to produce more precise cuts.
• The beam resolution from fiber lasers are around 1.06 μm, which metals can absorb fully. The result of this is faster cutting speeds in thin metals compared to CO2 lasers with the same power.
• Compared to CO2 lasers, fiber laser cutting machines also require less maintenance because they don’t contain mirrors or multiple moving parts.
• Fiber lasers are preferred when working with reflective metals like stainless steel, copper, and aluminum because there’s less risk of energy being reflected onto the machine during the cutting process.

Fig. 2: Fiber Laser Cutting Machine

Laser cutting can be used across multiple industries and for a variety of use cases. They are, however, most popular in industries requiring high precision and repeatability. As laser cutting requires no tooling and minimal set up, it’s widely used for customized signs and craft goods as well.

Laser cutters are often used in the automotive industry, for example, with sheet metal vehicle parts often cut with lasers. Other automotive parts that are often cut with lasers are the gears in a mechanical setup.

Examples of laser-cut parts across a range of industries include:

• Laser-cut brackets
• Enclosures for low to medium volume projects
• Craft goods such as custom mail boxes, stencils, stamps, etc.
• Metal signs and lettering
• Shims and washers for the aerospace industry
• Architectural ornaments
• Filters and screens
• A wide range of custom precision components.

Fig. 3: Laser Cut Parts

Laser cutting offers a number of advantages over traditional mechanical cutting methods (such as die punching or saw cutting) as well as other similar techniques, such as plasma cutting or waterjet cutting.

Many of the advantages stem from the fact that laser cutters cut with a narrow beam with a favorable wavelength and from the fact that there is a good level of energy containment in the cutting process. 

Next, we’ll share why these properties create advantages over other cutting methods.

Higher Accuracy and Smaller Kerf Sizes

Accuracy - The beam from laser machines is extremely focused and only touches a small surface area on the material, meaning that they produce very accurate and focused cuts. With accuracy levels of ±0.1 mm, laser cutters are often best where a high level of precision is required. 

Kerf - The narrow area of focus with a laser beam also results in smaller kerf widths compared to other methods. Kerf is the width of the area of material removed during the cutting process.

The kerf laser cutting makes is barely larger than the size of the beam. It is possible to produce kerf widths as narrow as 0.1mm with laser cutting, although kerf widths vary between 0.1mm and 1mm. The kerf thickness depends on the laser cutter being used and the material being cut.

In comparison, waterjet cutting produces a kerf width of around 0.9mm, while oxy-fuel and plasma cutting produce kerf sizes of 1.1mm and 3.8mm, respectively. To compare laser cutting to manual cutting methods, mechanical or hand saws generally produce a kerf size of about 3.175mm (10x the kerf of a laser cutter).

Having a smaller kerf size has the following advantages:

• Improved sheet utilization, which reduces waste and cost.
• Reduced need to offset cutting where accuracy is important.

High Levels of Repeatability

Laser cutters produce complex, precision parts in a repeatable and efficient manner, and this allows manufacturers to create multiple exact copies of the same parts over large production runs or even in separate production runs.

Laser cutting machines are CNC controlled, and generally operated using complex software to optimize part path, machine speed and sheet metal utilization. As well as this, laser cutters also cut without making contact with the material they are cutting. No wear or degradation occurs at the laser cutters cutting edge, meaning that the cutting action does not vary across a production run. This compares to saw cutting, for example, where the blade may deteriorate or become misshaped during production.

This advantage applies when comparing laser cutting to mechanical cutting methods, such as saw cutting. Waterjet cutting and plasma cutting offer similar levels of repeatability as laser cutting.

Less Material Contamination in the Cut Area

Many mechanical cutting methods require cutting oils to reduce friction and otherwise aid in the cutting process. Cutting oil can, however, be tough to remove after cutting, even with the aid of processes like shot blasting. This cutting oil can hinder later processes, such as the proper adhesion of finishes or protective coatings that are applied to a part after cutting, for example.

Laser cutting does not share this drawback because there’s rarely any need to use coolants or lubricants while cutting.

Limited Post-Cut Finishing Requirements

Laser cutting produces high-quality cut edges, which reduces the need for secondary finishing. In many cases, no secondary finishing is required after laser cutting.

The accurate, clean cuts that laser cutters leave usually have fewer surface imperfections related to the cutting process, such as burrs or excess material, that need to be removed after cutting. The effect of friction and wear forces that can cause surface imperfections like warping or mechanical distortions is also often avoided.

Laser cutting is often much preferable in this respect, when compared to mechanical cutting methods, such as saw cutting, shearing or drilling.   

Removing surface imperfections and completing other finishing processes can significantly increase production costs. Where laser cutting avoids the use of these processes, both time and money can be saved.

As well as there being reduced need for finishing with laser cutting, there is also usually no need to clean laser cut parts after cutting. Again, this can be an advantage over other cutting methods.

Laser Cutting Offers More Flexibility

The flexibility of laser cutting presents itself in two folds.

The first is in its cutting versatility and in the broad range of custom designs and shapes that can be produced through laser cutting. Often laser cutting is the best thing for highly complex and intricate parts. When compared to other methods, such as sawing, CNC milling, flame cutting and even plasma cutting, laser cutting is much more adaptable.

Often laser cutting can quickly do in one cutting process what might need several alternative cutting processes.  Certain part geometries or designs that are possible with laser cutting may not be possible at all with other methods.

As well as being able to perform many different types of cut, laser cutting can also be used for a range of different material types and thicknesses. One point worth noting, in this regard, is that laser cutting can be used to cut plastics and wood, whereas plasma cutting cannot.

Laser Cutting Offers the Best Sheet Utilization

Fig. 4: Laser Cutting Sheet Metal

As a combined result of the smaller kerf widths, lower levels of mechanical distortion, little to no surface imperfections and tighter tolerances, it’s possible to cut more parts from the same sheet with laser cutting.

With laser cutting, it’s possible to use as much as  94%+ of a sheet. This reduces cost and waste which translates directly to lower part costs than other cutting methods.

Fiber lasers are particularly good when it comes to sheet utilization.

Laser Cutting Provides Superior Speed

Laser cutters can reach speeds of up to 1200 inches (3050 cm) per minute. As such, they offer superior cutting speed compared to traditional cutting methods like wire cutting and bandsaw cutting.

Cutting with a bandsaw, for example, will take about 10 times as long as it takes with a laser cutter. Using a wire cutter may take up to 100 times the amount of time.  Plasma and water jet cutting are also generally slower than laser cutting, except on very thick materials or in cases where the laser wattage is relatively low.

On top of this, the entire laser-cutting process is automated. There’s no need to halt the process to adjust the sheet metal or machinery when cutting intricate parts. All these factors increase the speed of production.

Table 1: Comparison of Cutting Technologies: Laser, Waterjet, Plasma, and Mechanical

For all its advantages, laser cutting does also have some drawbacks. These include:

Hazardous Vapors and Fumes from Melting Materials

Laser cutting uses heat to melt or vaporize materials, which may generate hazardous vapors and fumes that pose significant health risks to machinery operatives. This makes it unsuitable for certain materials.

Some of materials that should not be fabricated with laser cutters are:

• Acrylonitrile butadiene styrene (ABS)
• Epoxy resins
• Polyvinyl chloride (PVC)
• Laminated Fiberglass
• Polycarbonate (PC)
• Polystyrene and Polypropylene Foam

Other disadvantages related to the cutting process include the risk of eye damage to operatives during cutting and the risk of producing sharp cut edges.

Limitation On Material Thickness

Laser cutters are limited when it comes to maximum cutting depths. Waterjet cutters, CO2 cutters and many mechanical cutting methods can all cut thicker materials than laser cutters.

There are also variations in maximum thickness between CO2 and fiber lasers. The thicker a material is, the greater the power required to cut through it, and CO2 lasers are able to cut the thickest materials because of their higher power outputs.  

• The maximum permissible material thickness for a fiber laser is 20mm.
• The maximum thickness for CO2 lasers is 70mm.

When laser cutters are used to cut thicker materials than they are designed for, issues such as poor edge finishes and lost materials due to melting can arise.  

Laser cutters are still great when used for the correct material thicknesses. Komaspec can laser cut materials, within the range of accepted thickness, at the following tolerances:

• Less than 1.0 mm with a tolerance +/- 0.05 mm
• Between 1.0 mm and less than 2.0 mm with a tolerance of +/- 0.05 mm
• Between 2.0 mm and less than 5.0 mm with a tolerance of +/- 0.07 mm
• Greater than 5.0 mm and less than 20.0 mm with a tolerance of +/- 0.20 mm

Table 2: Laser Cutting Capabilities: Material Thickness and Tolerances

Material Hardening

The high temperature of cutting with a laser beam can alter the structure of the material being cut, which, when followed by rapid cooling, may create a hardened zone at the cut area. This is referred to as the “heat affected zone,” or HAZ

Per this research paper, the “microhardness in the hardening zone increases as laser power increases,” so while this is generally not an issue with thin or quickly cut parts as heat transfer is minimal, it becomes more troublesome with very thick and slow-cut parts, as more heat is transferred to the material and as a result the HAZ will be larger.

The hardening of laser cut edges due to processing may be problematic in some applications. Parts that require finishing processes, such as with powder coating or painting, for example, may need additional processing following laser cutting before the finish can be applied. The addition of this step increases both the turnaround time and total processing cost.

Material Limitations

Laser cutting can be used on a wide range of metallic and non-metallic materials. It can, in fact, be used on more materials than both waterjet cutting and plasma cutting. There are limitations, however, and there can be further limitations with certain laser cutter types and when assistive gases are used during cutting.

Table 3: CO₂ vs. Fiber Laser Cutting: Material Comparison

The biggest advantage with laser cutting is that it allows for fast, highly accurate and highly repeatable  production of cut metal and plastic parts.  

• Fast cutting speeds for most material thicknesses
• Excellent precision for cost.
• Laser cut parts require little to no post-cut finishing.
• High material utilization when nesting multiple parts
• More suitable for multiple material production runs.
• No material contamination

There are also no upfront costs in ordering laser cut parts with Komaspec.

Komaspec is an on-demand provider of sheet metal parts capable of servicing your custom metal needs. Our capabilities include laser cutting, laser engraving, threading and chamfering and many more. We even offer instant quotation and DFM capabilities through our sister company, Komacut. Upload your drawings today for factory direct, real-time pricing.