Plasma and Laser Cutting fabrication solutions work in completely different ways and provide different results. It is therefore important to choose the right one for your specific projects to avoid misapplications and loss of value. 

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Wondering whether plasma cutting or laser cutting is the best option for your project? This discussion provides a brief overview of these two metal fabrication processes. At Automated Metal Processing, we specialize in laser cutting because of its high tolerance, exceptional quality and the economical price that we can offer our customers.

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PLASMA CUTTING BASICS?

Plasma cutting dates back to the 1950s and 60s. It was developed as an alternative for flame cutting, which fell short when cutting materials such as stainless steel, copper and aluminum. The process forces compressed air, oxygen or other inert gases through a nozzle at the same time that an electric arc is passed through the gas. This combination changes the gas into plasma (an electrically conductive ionized gas), which is hot enough to melt metal. Plasma cutting provides an efficient means to cut thin and thick materials. As far as the hand torches go, they can generally handle a steel sheet with a thickness up to 38 mm. Although, more powerful computer controlled torches can cut up to 150 mm thick steel sheets. Since plasma cutters produce a lot of localized heat, they are very effective for cutting and welding sheets in angled or curved shapes.

Plasma cutting introduces certain disadvantages, as well as advantages. When it comes to disadvantages, plasma cutters are limited to the thickness of the working material, the quality of cutting is significantly lower than with lasers and last but not least, the power consumption is relatively high compared to laser cutting. 

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WHAT IS LASER CUTTING?

Laser cutting represents the latest thermal cutting technology that came after plasma cutting. The word ‘laser’ is generally known to be a device for producing a beam of light that can measure things or heat things at very high temperatures. But how does light actually cut through a steel plate?

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How laser cutting works?

The laser beam is a column of very high intensity light which is about 3/4 of an inch in diameter. It travels from the laser resonator, which creates the beam, through the bore of a nozzle right before it hits the plate. Unlike Plasma cutting, laser cutting uses a computer-directed high-power laser in conjunction with oxygen, nitrogen or compressed air to melt, burn, vaporize or blow away the material being cut. So also passing through that nozzle bore is a compressed gas such as Oxygen or Nitrogen. The consumption of the resonator gas is generally low, while its purity and formation is significant. As far as the cutting gases go, oxygen is used for low-alloy and unalloyed steel, while nitrogen is used with stainless steel, nickel alloys and aluminium. The correct choice of cutting gases provides clean edges and preservation of properties of the base material.

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By focusing the large beam down to a single pinpoint with the help of light-bouncing mirrors or 'beam benders', it results in rapid heating, melting and partial or complete vaporizing of the plate. On a CNC (Computer numerical control) laser cutter, the laser cutting head is moved over the metal plate in the shape of the desired part, thereby cutting the part out of the plate.     

The laser cutting process has a small kerf width and heat-affect zone so this makes it possible to cut very intricate shapes and small holes. Learn about our step by step fabrication process in our Expert Guide To High-precision Custom Metal Fabrication.

The first laser cutting machines were created to cut holes in diamond dies in the mid-1960s, then for cutting titanium in the aerospace industry. Since then, laser technology has expanded into many settings beyond industrial manufacturing. The advantages of laser cutting have been made more significant by the fact that the whole operation is controlled by CNC - aided by computers.

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Advantages of laser cutting‍

• Accuracy & Precision - Laser cutting guarantees outstanding performance, smoother edge finishes and clean cuts
• Versatility - Cutting through materials of all thicknesses, and laser beams can be easily manipulated resulting into a desired output of high quality
• Speed & Repetition - The processes performed with laser cutters can be done in no time and the repeated tasks deliver the same high standard results
• Minimal Waste - mostly due to the kerf width, the sheet metal material can be utilized to the fullest extent, leaving minimal waste behind
  
  

Applications and uses where laser cutting outperforms plasma cutting:

• For processes such as cutting, drilling, engraving, ablation, welding and structuring (whereas plasma is limited to only cutting)
• Cutting of flat sheet steel from very thin (0.003”) to medium thickness (1” – 1.5”)
• For cutting small holes in thicker materials (where plasma is 1.5x material thickness, laser technology can cut approximately 0.375x the material thickness)
• Improved positioning tolerances and better fitting together of parts
• Faster cutting speed and delivery time due to advanced technology, ability to change settings between projects, etc., for common material thicknesses
• Finally, cutting edge (degrees to parallel) is better with laser cutting than with plasma cutting

Plasma cutting could be considered for:

• Cutting of sheet metal and plate for greater thicknesses (up to 2-3”, depending on the material)
• Highly reflective metals

KEY TAKEAWAYS

While the capital investment in laser cutting technology is much higher than for plasma cutting machinery, the superior cutting abilities, tolerances and overall quality of laser cutting made it a clear choice for us at Automated Metal Processing. The speed and increased productivity of our LaserTech machine also means quicker turnarounds and cost savings for you. 

Contact us today to discuss your specifications and needs. We’ll help you decide if laser cutting is the best choice for your project.

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