When you import a DWG or DXF file, each layer in the file is assigned a line weight based on the pen number-line weight settings.
Revit LT can import pen numbers from a DWG or DXF file and map them to a Revit line weight. You can then save these mappings in a text file, and they become the set mappings for the project.
Revit LT includes the following files with pen and line weight mappings:
These files reside in the following location:
%ProgramFiles%\Autodesk\Revit LT 2023 Release\Data
To define line weights for imported files
The Import Line Weights dialog displays the mappings in the importlineweights-dwg-default.txt file.