The HF Contact type typically found in budget machines uses a high frequency high voltage spark to ionise the air through the torch head and initiate an arc. The arc can only be formed if the torch is in contact with the job material. HF Contact type machines are not suitable for applications involving CNC cutting.

Plasma torches were once quite expensive, usually at least a thousand U.S. dollars. For this reason they were usually only found in professional welding shops and very well-stocked private garages and shops. However, modern plasma torches are becoming cheaper, and now are within the price range of many hobbyists. Older units may be very heavy, but still portable, while some newer ones with inverter technology weigh only a few pounds yet equal or exceed the capacities of older ones.

The Pilot Arc type uses a two cycle approach to producing plasma. First, a high-voltage, low current circuit is used to initialize a very small high intensity spark within the torch body, thereby generating a small pocket of plasma gas. This is referred to as the pilot arc. The pilot arc has a return electrical path built into the torch head. The pilot arc will maintain until it is brought into proximity of the workpiece where it ignites the main plasma cutting arc. Plasma arcs are extremely hot and are in the range of 15,000 degrees Celsius.