How Plasma Cutters Work

 

There’s probably no metal cutting tool that compares to the plasma cutter. Plasma cutters are the tools to use when you need to cut metal in a clean and exact pattern. It’s probably the closest thing we’ve got to the laser!

Don’t confuse a plasma cutter with a welding torch though. Although the manner in which they’re applied may be similar, the welding torch cuts through metal with a flame. The plasma cutter on the other hand, cuts through metal with compressed air, inert gas, and a high voltage charge. The plasma cutter is also safer than the welding torch because it uses inert gas instead of explosive gas.

When the charge arcs through the air, it ionizes the gas to 15,000 degrees Celsius – resulting in what we call plasma. In a way, you can think of plasma as controlled lava – hot enough to melt through the toughest metals without affecting surrounding areas of the air stream. 

Because of this control, plasma cutters are appropriate tools for cutting small pieces of metal. But they weren’t always perfect.
In the early stages of development, plasma cutters weren’t so accurate largely due to the fact that they once used a flame to heat metal the same way that the welding tool uses. Today’s plasma cutters however have been improved so much, metal artists use them to create highly detailed and intricate works of art. On a low setting, the right kind of plasma cutter can burn off paint. (Talk about precise!) On a higher setting, the same exact cutter can cut through 1/8 in of steel at a rate of 9 in./minute.

Now you might think that these mini-lasers if you will, cost a bundle but they’re really quite affordable. You can buy a Firepower 12 amp plasma cutter – complete with its own air compressor -- for just $998.75.

For $1,350, you can get a Lincoln Electric Welder’s Century 25 Plasma Cutter which is suitable for auto body repair work. This cutter removes high frequency harmonics with an earthed cutting arc. (High frequency harmonics can damage the electronics inside a car.) And it also has a built in air compressor with an adjustable regulator. The regulator controls the size of the plasma stream so you can play with its intensity and adjust its affect on various metal thicknesses up to 3/16.

Then there’s the Miller Auto Arc 4500 Plasma cutter. It sells for about $2,500 but it’s a lot stronger and more pliable than the others described. It comes with a 27 amp supply and a powerful air compressor that enables the tool to cut through ½ in. of steel as though it were cutting through butter.

When you’re ready to get one of these bad babies, be sure to select one that matches your need and your budget. Don’t get the most powerful cutter that you find unless your job requires it. If you perform small, occasional cutting jobs, then a lower-end cutter will suffice. Of course if you have to cut large pieces of metal on a daily basis, you’ll need to investigate the stronger models.