DESIGN

INTERSECT

This command creates a new solid from the intersecting volume of two or more solids or regions. AutoCAD will find where the two objects have an volume of interference and retain that area and discard the rest. Here is an example of this command shown below:

The INTERSECT command combines the volume of one or more solid objects at the areas of interference to create one solid object.

Command:INTERSECT
Select objects: (SELECT THE BLOCK) 1 found
Select objects: (SELECT THE CYLINDER) 1 found
Select objects: (ENTER)

You can intersect solids that are not touching - they will become one object.

Try these 3 boolean commands with various 3D solid objects to get familiar with them.