Steel fabrication involves three main steps: cutting, bending and assembling. There are different processes in each of these categories, and if you want to take an active role in the fabrication process, you need to decide which approach is best for your project. Cutting can be done manually or with machines that shear, saw or chisel the metal, but you can also use torches. The two most common options are plasma torches and oxy-fuel torches. To help you decide between these two types of torches, here's a closer look at their pros and cons.

How Plasma Cuts Steel

Often considered the fourth state of matter, plasma is not a liquid, a solid or a gas. Rather, it's somewhere between a liquid and a solid. With a plasma cutter, electricity and compressed air work together to create plasma gas. Then, the gas comes through a nozzle of the torch and uses its heat to cut the metal.

How Oxy-Fuel Torches Work

Oxy-fuel torches also use heat to cut metal. Essentially, these cutting tools direct a high-powered, very hot jet of oxygen at the metal. That heats the metal to ignition temperatures, which causes a chemical reaction. Then, the metal separates as part of that reaction. You can use different gases or alternate fuels, including acetylene, propane, propylene and natural gas with your oxy torch, but the best option varies based on the job you are doing.

Advantages of Plasma

If you want to use plasma, you need access to electricity and compressed air. In some situations, that is easy to find, but in other cases, you may need to choose a different cutting system due to the challenges of keeping these accessories on hand. That said, plasma is easier to use than oxy-fuel, and when working with relatively thin sheets of metal, plasma is more accurate. It also works well with stacked sheets of metal.

Benefits of Oxy-Fuel Cutting

As indicated above, you need a bit of extra knowledge when you use an oxy-fuel torch in the metal fabrication process. If you want your fabricators to use oxy-fuel, you should make sure they have experience and understand which supplemental gasses are best for your particular project. However, with the right knowledge, oxy-fuel torches can be extremely powerful. They cut through metal that is significantly thicker than the metal you can cut with a plasma cutter, and surprisingly, these cutting systems tend to be more portable than their plasma alternatives. As a result, if you are hiring someone to do metal fabrication at a work site, you may want to request oxy-fuel cutting.

Choosing Between Plasma and Oxy-Fuel Torches

As a general rule of thumb, plasma works better with ferrous metals. That refers to any metal alloy that has iron in it. Oxy-fuel torches, in contrast, are better suited to nonferrous metals. As a result, the type of metal you're using in your fabrication process can dictate which cutting method you should use.

If you want portability, oxy-fuel torches are traditionally the best option, and as indicated above, they don't need the electrical and compressed air support that plasma cutters need. However, plasma torches are becoming more portable, and they require less clean-up at the end of the process. Additionally, when you use plasma, you don't have to heat up the metal, and that saves time.

There are pros and cons to both options. Ultimately, you need to consider the type of metal you are using, the conditions on your job site, how much clean-up you want to do and the accuracy you want with the cuts. To learn more, contact a metal fabricator directly, and they can talk with you more extensively about the cutting options.