OK... so I'm the guy who discusses the quantum mechanics
of the lightbulb...

Anyway, the tension on the Legacy wing spar bolt should
be sufficient to clamp the the two spars together so that
they have enough friction to resist motion under all operating
loads. In other words, the bolts are never in shear, always
in tension. The shear loads are taken by the spar faces
that are clamped together.

The spar bolts should be torqued tight. The aluminum inserts
in the spar should take a compressive load comparable to the
bolt's tensile strength. The joint is designed so that you
don't have to worry about crushing carbon or core when tightening
the bolt. I don't remember the bolt diameter, but I expect that
it should be tightened to the nominal torque for that size and
thread of AN bolt.

-bob mackey