# Boolean and combining objects for 3D printing

I'm testing some tolerances between Blender 2.83 and a 3D printer I'm trying to combine a nut created with the bolt factory add-on with a cube and have the center be hollow. How can I do this see image of problem of the center of nut not being hollowed out. (I tried using the Boolean modifier)

Bolt and cube

After the Boolean operator I can't delete the face in the center of the nut see red arrow (I'm trying to hollow the nut out to test the 3D printed nut threads with a 3D printed screw)

2. Pick the item you want to drill/place the hole in (box or object) and choose Difference Note: You could also use Ctrl+Shift+- (this keyboard combination does bool difference)