Plasma cutting is a process that cuts through electrically conductive materials by
means of an accelerated jet of hot plasma (Electric arc). Typical materials cut
with a plasma torch include steel, stainless steel, aluminum, brass and copper,
although other conductive metals may be cut as well
The basic plasma cutting process involves creating an electrical channel of
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 accomplished by a compressed gas (oxygen, air, inert and others
depending on material being cut) which is blown through a focused nozzle at
high speed toward the workpiece. An electrical arc is then formed within the gas,
between an electrode near or integrated into the gas nozzle and the workpiece
itself
The electrical arc ionizes some of the gas, thereby creating an electrically
conductive channel of plasma. As electricity from the cutter torch travels down
this plasma it delivers sufficient heat to melt through the workpiece. At the same
time, much of the high-velocity plasma and compressed gas blow the hot molten
metal away, thereby separating, i.e. cutting through, the workpiece.
Plasma cutting is an effective way of cutting thin and thick materials alike. Hand-
held torches can usually cut up to 38 mm (1.5 in) thick steel plate, and stronger
computer-controlled torches can cut steel up to 150 mm (6 in) thick. Since
plasma cutters produce a very hot and very localized “cone” to cut with, they are
extremely useful for cutting sheet metal in curved or angled shapes.