Typically, you convert a .pat to .dwg if you want to see the visual representation of the hatch as actual vector lines rather than a dynamic fill pattern. Alternative: Importing into AutoCAD
the .pat file directly into AutoCAD rather than converting it into a separate DWG file: Locate Support Path : Open AutoCAD and type . Go to the tab and find Support File Search Path Add Your PAT Folder , and select the folder where your .pat file is saved. Apply the Hatch command. Your custom pattern will now appear under the User Defined hatch menu. Save as DWG convert pat file to dwg online
However, the best workflow to is: