Click Home tabLayers panelMechanical Layer Manager. Find
In the Mechanical Layer Manager, select the layers you want to delete.
Click .
Note:
Specific layers, such as the current layer and the layer AM_0 can’t be deleted.
Layers that are used by objects or external references cannot be deleted. If such objects are detected, AutoCAD Mechanical toolset displays the Mechanical Layer - Delete dialog box to let you delete the objects on the layer or move them to a different layer.
If you delete a mechanical layer, the layer is deleted, but the definition remains.