CNC plasma cut brackets, header flanges, and other two- dimensional shapes can easily be produced.  Once cut, shapes can be folded, bent, welded together, and otherwise modified to create three dimensional structures.

Since the plasma arc process creates a slight bevel in the cut face, the thickness of the material being cut is a big factor in whether or not the outcome will be satisfactory.  The top of a hole will be slightly offset from the bottom of the hole, and a slightly larger diameter.  This is of little consequence when cutting 11 gauge (.125″ thick) material but may prove unsatisfactory with thicker pieces.  Also, the thicker the material, the larger the minimum hole (or any interior shape) must be.

As with any shape being cut, interior shapes (cutouts) must be spaced apart from each other and from the outer edges.  This is necessary due to the kerf (cut) width produced by the plasma torch.  The thicker the material and the more the amperage, the larger the kerf width will be.  If insufficient space is allowed, interior shapes may overlap, or pieces may unexpectedly fall out.

Here are a few rules of thumb –

Bolt holes may be cut satisfactorily in thinner material but become beveled from top to bottom as it becomes thicker.

The faster a material conducts heat, the worse job plasma arc will do in it.  Aluminum and brass conduct heat quickly, causing surfaces near a previous cut to become hotter, influencing the required cutting speed.  It is difficult, if not impossible to continuously adjust the cutting speed throughout the torch travel.  Therefore, the speed will be too fast in some areas and too slow in others, diminishing cut quality.

The cut edge is always going to be better on the right side of the torch travel.  Interior shapes should be cut counter-clockwise, and outside (perimeter) cuts made clockwise.CNC Plasma