Plasma cutters have been in use since the ‘60s as a method of cutting or cutting shapes out of metal. During World War II, a new form of welding emerged using inert gas together with an electric arc. This style of welding protected welds from the effects of oxygen and nitrogen in the atmosphere, which could turn a weld porous and brittle. Scientists later discovered that by tightening the hole the arc emerged from and increasing the velocity of the shielding gas, they could produce a significantly hotter arc. However, with this development, the tool no longer acted as a welder used to join metals. The heat melted metal through and the high velocity gas mechanically blew the unsupported material away. For this reason, the new device was used purely for cutting and became known as the plasma cutter.

A Closer Look at Plasma

There are four states of matter. We typically interact with only three: solids, liquids, and gases. When gases are superheated, they turn into the fourth state, plasma. In a plasma state, atoms of an element begin to split, separating electrons from their nucleus. When the electrons and ions (the positively charged nucleus of an element) collide with other fast-moving electrons, they release a great amount of energy, producing the high heats that translate into the torch’s cutting power.

How Welders Use Plasma Cutters

Since their invention, plasma cutters have become an indispensable tool to welders and students in welding training. They are used in airplane and automobile manufacturing, shipfitting, construction, metal fabrication, and a variety of other fields. Even locksmiths may use them to bore into safes for customers. Plasma cutting is used primarily on steel and other non-ferrous materials less than an inch thick. It also has a number of useful specialty applications, such as cutting expanded metal and non-linear shapes. Using a plasma cutter is typically a very fast process. Also, while plasma cutting equipment has traditionally been fairly expensive and used mainly in large-scale operations, today welders can find models of cutters that vary in cost and size to suit the jobs they perform.

Before investing in a plasma cutter, think carefully about how you will be using it. Average metal thickness, desired cutting speed, and other factors will help determine how powerful the plasma cutter needs to be.

At Tulsa Welding School, students are taught to use both carbon arc and plasma cutting techniques as part of the structural welder training portion of the Professional Welder Program. For more information about welder classes and training, contact Tulsa Welding School.

Resources:

http://www.lincolnelectric.com/en-us/support/welding-how-to/Pages/plasma-cutting-basics-detail.aspx
http://home.howstuffworks.com/plasma-cutter.htm