Advice & Tips

What Is Plasma Cutting and How to Use It?

After using a plasma cutter, you won’t want to use oxy-fuel cutting, grinding discs, or anything else of the sort again. In any metalworking environment, plasma cutters are an incredible tool to have because they are simple to use and less expensive to operate than oxy-fuel cutting.

What Is Plasma Cutting?

Plasma cutting uses an accelerated jet of hot plasma to cut through electrically conductive materials. Other conductive metals may also be cut with a plasma torch, but the most common materials to be cut with one are steel, stainless steel, aluminum, brass, and copper. In fabrication shops, auto repair and restoration businesses, commercial building projects, and salvage and scrapping businesses, plasma cutting is frequently used. Plasma cutting is used widely, from large-scale industrial CNC applications to small hobbyist shops, thanks to the high speed and precision cuts combined with the low cost.

In order to cut with plasma, a superheated, electrically ionized gas, i.e. plasma from the plasma cutter itself, through the workpiece to be cut, thus forming a completed electric circuit back to the plasma cutter through a grounding clamp. This is done by blowing a compressed gas—oxygen, air, inert, or another gas, depending on the material being cut—through a focused nozzle toward the workpiece at a high rate of speed. Then, between an electrode located close to or built into the gas nozzle and the workpiece itself, an electrical arc forms within the gas. Some of the gas is ionized by the electrical arc, which results in the formation of a plasma channel that is electrically conductive. It generates enough heat to melt through the workpiece as the electricity from the cutter torch travels down this plasma. The hot, molten metal is blown away by a large portion of the high-velocity plasma and compressed gas at the same time, causing separation, i.e. cutting through, the workpiece.

Plasma cutting works well for both thin and thick materials. Typically, hand-held torches can cut through steel plates up to 38 mm (1.5 in) thick, while stronger computer-controlled torches can do so up to 150 mm (6 in). Plasma cutters are very helpful for cutting sheet metal into curved or angled shapes because they produce a very hot and localized “cone” to cut with.

The Operation Of a Plasma Cutter

In order to ionize the atoms and produce a “plasma arc,” plasma cutters use DC voltage to heat compressed air to a very high temperature. This moves at a temperature of roughly 25,000–30,000 degrees Fahrenheit through the cutting tip’s small hole, which is typically 0.9–1.5mm wide.

The tiny plasma jet penetrates, melts the metal, and then pushes the molten metal out of the way. When compared to results from oxy-fuel cutting, it is extremely focused.

What Metals Can A Plasma Cutter Cut?

The plasma cutter works well with any type of electrically conductive metal. These types of metal can be cut from 1-2mm thick sheet metal up to 1-2 inches thick. Anything thicker will be challenging. The more risk there is from all the sparks produced, even in automated plasma cutters, the thicker the metal tends to be. You should put your safety first, even when cutting through thin metal. This category of metal includes the following types of metal:

1): Mild Steel
2): Stainless steel
3): Carbon steel
4): Copper
5): Brass
6): Aluminum
7): Expanded steel

What Is Inaccessible To A Plasma Cutter?

Is plasma cutting a universal fabrication technique? No, plasma cutting cannot process non-conductive materials because the material needs to be electrically conductive to respond to the ionized gas coming from the torch. Plasma cutters, for example, are unable to cut materials like wood, glass, plastic, or metals with poor conductivity like manganese, lead, tungsten, and tin.

6 Simple Plasma Cutter Installation Procedures:

1): Attach your plasma cutter to an appropriate air compressor.

2): Depending on the plasma cutter you bought, connect it to a 240V or 415V power source.

3): Attach the earth lead to your workpiece.

4): Attach the plasma cutting torch to the machine that uses it.

Choose your cutting amperage in step 5 (more amps for thicker materials).

6): Turn on your torch, move it across the metal being cut by the plasma arc, and press the switch on the torch handle.

Starting points include the work’s edge and the metal’s middle. Use a circle cutting kit to create perfect circles, then use a template to create special shapes.

Plasma cutters are fairly portable because there aren’t any large gas bottles to lug around, and the reduced heat affected zone and narrower cut width compared to oxy-fuel cutting is a huge advantage.