In peg testing conducted at the University of Wyoming, we were able to directly correlate the strength of a peg in a mortise and tenon joint to the specfic gravity (density of the peg). In essence, the densier the peg, the stronger the joint.
And, the shear values listed on the Center of Wood Anatomy Research are parallel to grain values, not perpendicular to grain, which is how pegs are loaded.
Hope this helps,
Joe
