Below is a list of commonly used AutoCAD commands that are used when working with 3D solids.

1. POLYLINE (PL) – The POLYLINE command will allow you to create a 2D polyline. When working with the Solid Model Tools, it is crucial to close a polyline when trying to make a shape. Not closing a polyline will result in a mesh object being created. Mesh objects are not recognized by the Solid Model Tools.
   
2. EXTRUDE (EXT) – The EXTRUDE command will extrude a 2D object into a 3D object. When using the EXTRUDE command, the original 2D object will be removed from the drawing.
   
3. PRESSPULL (PRESS) – The PRESSPULL command will extrude a 2D object into a 3D object, or extend a 3D surface. When using the PRESSPULL command with a 2D object, the 2D object will remain in the drawing.
   
4. BOX – The BOX command will allow you to create a 3D box by selecting 3 points in the X, Y, and Z axes.
   
5. 3DMOVE (3M) – The 3DMOVE command will allow you to move an object in either the X, Y, or Z-axis.
   
6. 3DROTATE (3R) – The 3DROTATE command will allow you to rotate an object about the X, Y, or Z axes.
   
7. 3DPOLYLINE (3DPOLY) – The 3DPOLYLINE command will allow you to create a polyline with points that can exist in the X, Y, and Z axes.
   
8. UNION (UNI) – The UNION command will allow you to join separate 3D objects into one.
   
9. SUBTRACT (SU) – The SUBTRACT command will allow you to subtract 3D objects from another 3D object.
   
10. SLICE (SL) – The SLICE command will allow you to create a joint through a 3D solid.