AutoCAD Mechanical adds manufacturing records to two-dimensional drawing geometry. Lines, arcs and circles can become component views, and those views can belong to a part or assembly. The Mechanical browser displays that hierarchy beside the drawing. This changes how AutoCAD Mechanical selects and reuses geometry: the user can work with a complete part view or assembly instead of selecting every line that draws it. The DWG still contains drawing geometry, while the mechanical structure records how that geometry belongs together.
A component and its views are separate levels
A part contains one or more component views. An assembly can contain other components as well as its own views. The browser tree keeps these levels visible, and its context menu performs component operations. Selection modes can select a part or assembly in model space rather than isolated lines and circles. This hierarchy matters in a flat drawing because the same part may need more than one view.
Reuse can remain linked to another drawing
After a component exists, AutoCAD Mechanical can insert another instance instead of redrawing it. An external-reference component remains associated with its source drawing. This differs from redrawing the same lines as unrelated geometry because the Mechanical browser still treats the referenced item as a component.
Components and part references can update bill-of-materials data. AutoCAD Mechanical supports a main BOM, BOMs for assemblies and BOMs associated with drawing borders. A border BOM requires a border created with AMTITLE. Drawing an ordinary rectangle around the sheet does not create that association.
Mechanical layers ignore the current drawing layer
Automatic Property Management sends mechanical objects to predefined mechanical layers. If a required mechanical layer does not exist, AutoCAD Mechanical creates it. The current layer therefore does not decide where every mechanical object goes. Changing the current layer and then running a mechanical command can still place the resulting object on the layer assigned to that object type.
Enable structure before the first entity
Changing to the Structure workspace does not enable mechanical structure by itself. A separate status control or command enables it. After the drawing contains a structure entity, the same control cannot disable structure. This makes the initial choice more permanent than switching workspaces.
Existing drawings need another precaution. Autodesk recommends moving selected legacy geometry into a structure-enabled drawing instead of converting a completed non-structured drawing as one large operation. Autodesk also warns that mixing block structure or part references with mechanical structure can make BOM data confusing.
Plain AutoCAD can open a DWG that contains mechanical structure, but Autodesk warns against changing the structured geometry there when the file will return to AutoCAD Mechanical. AutoCAD Mechanical uses the structure records to select component views, parts and assemblies rather than isolated drawing entities.
