Plasma cutters use a high velocity super heated plasma to melt and then blow away the work piece metal. We understand that there are three common states of matter, liquid, solid, and gas. However, plasma is considered a fourth state of matter. Plasma is a gas that has been ionized by passing through a very hot electric arc. After the gas is ionized it becomes conductive and easily passes an electric current. The ionized gas then becomes plasma.
The plasma is forced through an orifice which concentrates the plasma to a very small diameter. The temperature of the restricted plasma increases to somewhere in the neighborhood of 30,000°F.
The velocity of the plasma is also increased to about 20,000 ft./s. The super hot plasma completes the electrical circuit from the plasma torch to the work piece and current flows through the plasma just as if it was an electrical wire. The super hot plasma almost instantly melts the work piece metal upon contact and the high velocity plasma pushes the melted metal out the bottom of the cut.
Buying a Plasma Cutter
When selecting plasma cutters for sale the most important consideration is how thick is the metal to be cut. The thickness of the metal determines the current output of the plasma cutter.
Smaller plasma cutters on the market have current outputs of 12 amps which is sufficient for a quality cut on 1/8 inch mild steel.
A plasma cutter output of 30 amps will perform a quality cut on 1/4 inch mild steel and a plasma cutter output current of 40 amps will quality cut half inch mild steel.
A very important point when comparing plasma cutters is the output current.
Plasma cutters require a clean, dry air supply was enough air volume. Typical air compressor requirements for a small plasma cutter would be for cubic feet per minute at 60 PSI and up to 7 ft.³ per minute at 90 PSI for a larger plasma cutter.
Another important factor to consider when buying plasma cutters is input power. Small plasma cutters operate on 110 V AC. These small plasma cutters are convenient, and portable, but they are only suitable for cutting 1/8 inch mild steel and gauge.
A plasma cutter operating at 110 V AC requires twice the input current of the same plasma cutter operating at 220 V AC. If portability is a requirement and if the metal to be cut is thin gauge up to 1/8 inch mild steel then a small plasma cutter operating on 110 V AC may be sufficient.
Unless portability is a requirement then I suggest buying plasma cutters that operate on 220 V AC.
Best Plasma Cutter Brands
- Hypertherm plasma cutters
- Miller plasma cutters
- Lincoln plasma cutters
- Thermal Dynamics plasma cutters
- ESAB plasma cutters
- Hobart plasma cutters
These are the major plasma cutter manufacturers and I suggest considering a Hypertherm plasma cutter as a first choice with either the Thermal Dynamics plasma cutter and Miller plasma cutter for a second choice, and then any of the others.
Both Hypertherm and Miller have a 3 year warranty on their plasma cutters. The Miller Spectrum line has a 3 year warranty on the power source and one year warranty on the torch. And likewise Hypertherm provides a 3 year warranty on their Powermax line of plasma cutters with one year on the torch. Thermal Dynamics has an impressive four year warranty on their power supply with one year warranty on the torch.
However any of these major manufacturers build good plasma cutters for sale. My personal preference is the Hypertherm plasma cutter because I own and use a Hypertherm 1000 plasma cutter and I like it very much. When I look at plasma cutters my first choice is Hypertherm however, the Thermal Dynamics four year warranty makes the Thermal Dynamics plasma cutter line worth looking at.
Since you are shopping for plasma cutters you may be interested in a brief description of how a plasma cutter works.
Take your time when shopping and compare plasma cutters for sale.