Jul 21, 2023
The best plasma cutter
A plasma cutter looks similar to an arc welder, but instead of joining metals, the job here is to cut through them quickly and accurately. We’ve been looking at the technical aspects so we can help
A plasma cutter looks similar to an arc welder, but instead of joining metals, the job here is to cut through them quickly and accurately. We’ve been looking at the technical aspects so we can help you decide which would suit your shop. In addition to our buyer’s guide, we’ve picked a few favorites. Top spot goes to the Lotos 50-Amp model, which comes from one of the best-known names in the industry, and delivers professional-grade performance and reliability.
Considerations when choosing plasma cutters
While other factors are important, maximum cut thickness is usually the headline figure. However, care is needed when looking at this. You should get two figures, one for “clean cut,” and a higher one for “severance cut.” The first is self explanatory — and what most will look for. The second is the thickness that the machine will cut through when pushed to its limits. However, the finish will be rough.
There’s another aspect to this, and it depends on the voltage. Most plasma cutters can adapt to either 110V or 220V power — but they may only reach their maximum cut on the higher voltage settings. It’s something worth checking, especially if you’re looking at budget machines.
Gas or air supply
Along with your plasma cutter, you’ll also need a gas or air supply. Traditionally pro shops would use argon, nitrogen or oxygen (the latter being potentially dangerous). Modern machines tend to use compressed air. If you already have a compressor you would like to use with your plasma cutter, you’ll need to check both PSI (pressure in pounds per square inch, and CFM (flow, in cubic feet per minute).
Plasma cutters generate a huge amount of heat, so they need periodic breaks to cool down. This is called the duty cycle, given as a percentage. Each model should provide information but the amps specified may not be the maximum. A 50A machine, for example, can probably run as low as 10A for cutting thin sheet. So, a typical duty cycle might read 30% at 35A, which means for every three minutes working at 35A, it needs to rest for seven minutes. Running at 20A, the duty cycle would be longer, while running flat out at 50A the duty cycle would be less. Duty cycles rarely exceed 60%, even on the most powerful plasma cutters.
Nozzles are either touch or non-touch, the advantage with the latter being that it doesn’t need to be in contact with the material. If the surface is bumpy, damaged, or has flaking paint, the plasma cutter works just like it would on clean, flat, bare metal.
Drag technology allows you to keep the nozzle in contact with the material, something that otherwise risks a double-arc (which could weld the torch to the metal). This makes it easy to follow a pre-drawn line to cut complex shapes — a popular option with decorative metalworkers.
The initial supply of electrodes and nozzles won’t last long, and this is an ongoing cost, so be sure to research in advance the price of these items for the unit you’re considering. An aftermarket supply can save money, but don’t be tempted by very cheap products that will affect performance.
Although you could find a cheap plasma cutter for less, we’d recommend spending around $250 to $300 for a reliable 40A or 50A machine. There’s lots of choice in the $400 to $600 range, and most people should find what they need for that kind of budget. High-power plasma cutters — 80A and up — will cost you anywhere from $1,000 to $3,000.
Q. Can’t I just cut with my welding gear?
A. If you just want to chop through thin sheet, it can be done, but you’ve got little control, and finish quality will be very poor. However, there are plasma cutter/welder combo machines available if you do a lot of both.
Q. What is welder’s flash?
A. It’s a painful eye condition that happens if you don’t wear a welder’s mask. UV light damages the corneas, leading to severe irritation that can last several days. It’s a bit like sunburn to your eyeballs! So always, always put on a mask before you cut.
Plasma cutters we recommend
Best of the best: Lotos’ LTP5000D Plasma Cutter
Our take: Powerful 50A tool offers excellent control on all surfaces.
What we like: Non-touch pilot arc is great for uneven, painted or rusty metal. 110/220 volt switchable. 3/4″ severance cut. Fast, simple setup.
What we dislike: Not much. A few owners have had faults from near new units, but warranty should cover replacement.
Best bang for your buck: Sungold Power’s Cut50 Plasma Cutter
Our take: Terrific value 50A machine for light commercial and home use.
What we like: Can run off 220V or 110V. IGBT inverter technology provides stable arc. Easy to use. 3/4″ severance cut.
What we dislike: Struggles to reach advertised maximums on 110V supply.
Choice 3: Amico’s Cut-40 Plasma Cutter
Our take: Reliable, entry-level machine from a well-known manufacturer.
What we like: Powerful enough for severance cutting up to 3/4″. Auto-adjusting voltage wherever you plug in. Surprisingly comfortable gun.
What we dislike: Nothing, but there are 50A machines for the same money.
Bob Beacham is a writer for BestReviews. BestReviews is a product review company with a singular mission: to help simplify your purchasing decisions and save you time and money. BestReviews never accepts free products from manufacturers and purchases every product it reviews with its own funds.
BestReviews spends thousands of hours researching, analyzing and testing products to recommend the best picks for most consumers. BestReviews and its newspaper partners may earn a commission if you purchase a product through one of our links.
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