Although metals are some of the hardest and most resilient materials on earth, they can still be cut and shaped to fit specific project requirements. And since different projects require different metals with a variety of shapes, you need to know which cutting process to use to get the desired shape or design. Cutting metal is categorized into thermal cutting processes and mechanical cutting processes, with the former being the one that is commonly used today. 

What is the Thermal Cutting Process Used for?

Thermal cutting involves a set of processes where heat from radiation energy, an electric arc, or exothermic reaction is used to oxidize, vaporize or melt metal to achieve the desired cut. Thermal cutting is primarily for shape cutting of cold and hot-rolled steel but can also be used on Aluminum and Stainless with varying degrees of success. Thermal cutting machines are probably one of the oldest forms of metal shape cutting short of the physical hammering/sawing/hacking methods. This post will cover the various tools and methods that can be used for thermal cutting, including burning and plasma tables.

Three Common Thermal Cutting Methods

Flame Cutting

Also referred to as "oxy-fuel cutting," flame cutting is a thermal cutting process where oxygen is used with a fuel source, such as acetylene or propane, to intensify a flame that produces enough energy to melt metal. The neutral flame produced during this process is used to heat a metal or any other material, and once it has melted, a high-flowing stream of oxygen/fuel severs the material and blows away the molten substance also known as ‘slag’ and if not completely removed from the material, ‘dross’. 

Plasma Cutting 

Unlike flame cutting, which uses oxygen-fuel mixture, plasma cutting utilizes an electrical arc as the source of heat. The electric arc is used to ionize and heat a gas that forms a plasma so intensely hot that material is literally vaporized within the plasma stream. The piece being worked is made to become a part of the electrical circuit, and once the plasma becomes superhot, it interacts with the grounded workpiece creating the desired cut. Several gases can be used as the plasma assist gas, depending on the material being worked on. Like in flame cutting, the superhot plasma gas is also used to sever the material and get rid of the dross.

Laser Cutting

This is the newest thermal cutting method, which uses laser energy to melt metal. During this process, a monochromatic and coherent light beam is formed inside a laser resonator, intensified to 2-30KW of power and then focused through a lens onto a workpiece. The laser emanating from the lens then burns, melts, and vaporizes the targeted section of the metal material, resulting in a clean cut. The common types of lasers that are used in the manufacturing industry include CO2 lasers, Nd, and Nd-YAG and of course the newest Direct Diode Fiber. 

Thermal Cutting Equipment Options

The type of equipment is based on the type of thermal cutting process being used but largely are vary similar systems utilizing a table to hold the material flat while the thermal torch processes it from above.  A CNC Controller moves the cutting head across the material surface with commands programmed from a computer to match the designers wishes. 

Oxyfuel Cutting Machines

Although they were the first types of machines to be developed, Oxy-Fuel, or flame-cutting machines continue to play an integral role in the manufacturing industry. While human-controlled oxy-fuel cutting machines have been doing great work, technology has led to the development of CNC flame cutting machines optimized for a broad range of operations. These systems are best suited when carving thick pieces of steal from 2” Thick up to 12”. Accuracy is measured closest with a tape measure on these types of cuts with edge quality being not important. 

Plasma Cutting Machines

Also known as plasma cutting tables, plasma cutting machines come in three types;

  • Air Plasma Entry Level: These machines are great for the home hobbyist without the need for higher accuracy and typically running on single phase power sources with a plasma that can easily be adapted for automation or hand held applications. Typical applications would include artwork, light fabrication, automotive repair etc. 
  • Air Plasma Industrial Grade: This is the most common choice for shops looking to add capability in plasma cutting to their options of cutting solutions. Able to provide good accuracy and a decent finish, the industrial grade Air Plasma can provide a fabricator a great solution in thermal cutting. Typical applications include fabrication job shop work & precision steel cutting, 
  • Hi-Definition Plasma: This is a special machine designed to get near laser like quality out of a plasma table. At usually 2-3x the price of the Industrial grade Air Plasma the Hi-Def machine boasts the best drive and motion system allowing for 3 decimal place accuracies while being combined with the highest definition plasma power systems which provide the cleanest edge and hole quality. 
    In a recent article we wrote about: Plasma Cutting: 4 Reasons Why You Need a Plasma Table In Your Shop Now and think you will appreciate this read. 

Laser Cutting Machines

Laser cutting machines offer the highest grade of accuracy and speed in a smaller range of materials then the Oxy-Fuel and Plasma comparisons. These machines are designed for tight tolerance work in gauge materials with the ability to cut with an intense focused heat source at speeds measured in thousands of inches per minute. 

Laser cutting machines come in three different types;

  • C02 laser cutting machines 
  • Nd: YAG/Nd: YVO Lasers
  • Fiber Lasers

Find a Thermal Cutting Machine in SFMS Large Inventory!

Whether you are looking for CNC plasma cutting, oxy-fuel cutting, or laser cutting machines, Southern Fabricating Machinery Sales (SFMS) is your one-stop-shop. As a leader in the machinery business, we take pride in our diverse range of thermal cutting machines that are sure to deliver top-notch solutions to your range of applications and customers. We take pride in helping fabricators and manufacturers from around the world, furnish their workshops with high-end cutting machinery to ensure that they deliver orders on time and increase their profit margins.

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