In this extension of the stacking technique, pieces are oriented face-to-face, but separated. Each piece is held in place on a longer bolt or threaded rod with a nut (and optionally, a washer) on each side.

You can also disguise the threaded rod and add a little more compressive strength by using a pre-formed standoff.

Illustration : Waterjet cut parts held apart by nuts and long bolts

Illustration : Another view of the assembly from the previous photo
showing how the parts are kept in place with nuts