Understanding "Severance" and Cutting Rates with Plasma Cutters and Welding Machines
Precision, efficiency, and speed are crucial in welding metal-based materials. Whether you're a professional welder or a DIY enthusiast, understanding the concepts of "severance" and cutting rates is crucial to achieving optimal results. Both terms are particularly important when working with plasma cutters and other welding machines, as they directly impact the quality and efficiency of your cuts.
What is Severance in Welding?
Severance refers to the upper-limit of thickness of material that a plasma cutter or welding machine can cut through. Welding machine manufacturers post a severance that’s greater than their actual recommendations for everyday welding thickness. While it’s perfectly normal to cut thicker material, you sacrifice cut quality and speed when cutting at the severance thickness.
Often times, you also need to account for a delay in travel time with thicker material. You’ll need to start at the edge of the material and have the machine fully cut through before being able to travel with the torch. Welders should also be aware that machines with different recommended cutting thickness come with difference severances.
For example: ESAB’s Thermal Dynamics CUTMASTER 82 has a recommended cutting thickness of 1” material, and a severance thickness of 1.5” material (33% difference). On the other hand, the Thermal Dynamics TD CUTMASTER 40 has a recommended cutting thickness of 1/5” material, and a severance thickness of 1” material (50% difference).
What is Cutting Rate in Welding?
Cutting rate refers to the speed at which a welding machine can cut through a material, often in “inches-per-minute” (IPM). Cutting rates can vary depending on the material's thickness, the machine's power, and the cut type. The thickness is usually the most volatile factor welders will work around, as manufacturers will already provide their machine’s capabilities, and typically base their recommendations on solid steel cuts.
When working within the machine's recommended cutting capacity, the cutting rate is faster, and the quality of the cut is superior. However, as you approach the severance thickness, the machine must work longer to cut the material. With thicker cuts, welders can expect slightly less precision and rougher edges, especially when the machine cannot sufficiently blow away molten metal. The resulting metal that adheres to edges is known as “dross”.
Depending on the project, time may become a factor in choosing the right machine for the cutting job. While it’s possible to cut severance-thickness materials at a regular basis, we highly discourage it in order to achieve the desired results the first time around. In the event that one needs to smoothen any edges from thicker cuts, we recommend a product like the FEIN Brushless 5" Variable Speed Angle Grinder to polish or cut away dross.
Why Are Plasma Cutters Great For Welding?
Plasma cutters are renowned for their ability to make clean and precise cuts through various metals including steel, aluminum, and copper. They work by creating an electrical arc that ionizes a gas, turning it into plasma. This plasma reaches extremely high temperatures and speeds allowing it to slice through metal with ease.
One of the main advantages of plasma cutters is that their cutting rates and severance capabilities are typically higher than those of traditional oxy-fuel cutting torches, making them a preferred choice for many professionals in the welding industry. Modern plasma cutters also include external air-compressing capabilities to reduce the amount of dross build-up in thicker cuts. They also work well for materials with gaps, such as perforated sheet metal, as the internal air compressor and plasma cutting power can weave in-and-out of material contact in a single trigger pull.
We recommend the Lincoln Electric Tomahawk 30 Air Plasma Cutter for plasma cutting needs. It can cut through materials up to 1/2”-thick with ease and offers an impressive cutting speed, making it an excellent choice for both professionals and hobbyists alike. With its built-in air compressor and robust design, this plasma cutter ensures consistent performance and high-quality cuts. We have a detailed video showing the Tomahawk 30 Air where we break down all components and features and perform cutting with this machine in particular.
For those that love the design language and features of the Tomahawk 30 Air, but need a heavier duty machine, we recommend the Lincoln Electric Tomahawk 45 Plasma Cutter. It has an additional 1/4” of max severance (up to 3/4” cuts), and possesses extra features, such as Parts-in-Place, to detect the installation of consumables and accessories.
Which Lincoln Electric Plasma Cutter Is Better?
Understanding severance and cutting rates is crucial for anyone involved in welding or metalworking. To achieve the best results, it’s essential to have the right tools at your disposal. The Lincoln Electric Tomahawk 30 Air Plasma Cutter is an excellent investment for those who need a versatile, reliable, and powerful plasma cutter to make cuts with an emphasis on speed. For heavier-duty, higher-quality cuts, the Lincoln Electric Tomahawk 45 Plasma Cutter is the clear choice.
Welders can’t go wrong with either choice so long as their machines are used for their intended target materials and thicknesses. Both machines can be used in typical indoor shop applications, as well with engine-driven welders, such as the Lincoln Electric Maverick 260X Diesel (Kubota) Engine Driven Welder / Generator (As seen in our Youtube Video) for outdoor applications where there is no power source.
For a deeper dive on the capabilities of both products, check out our YouTube video covering both machines.