On 29 May, 19:00, "Roger Mills" wrote:

It's all a bit academic anyway, because if you hold two bits of wood tightly
together - be it with a bolt or screw - any shear force if provided by the
friction between the mating surfaces rather than by the bolt or screw.

Not good design though. It's very dificult (i.e. impossibly
impractical) to maintain compressive forces and thus friction in a
design of bolted timber. Moisture or thermal movement, then
compressive yield in the timber, cause such a joint to go loose and
fail after a few seasons.