Steel Beam
AutoCAD is and architectural software and works well for exporting flat 2-D pieces to plate processing machines. Where it falls short is in its ability to export files for 3-D shapes like beams, channel, angles etc. AutoCAD exports both DWG files and DXF files which are perfect for plates.
Another problem is that when cutting thicker portions of a piece, even using light wide-flange beams (e.g. the radius at intersection of the web, and the flange), it is not uncommon for the flame back to blow away, which can damage the plasma head.