Pacific Post and Beam entered three tenons in the Tenon Testing at the 2012 Western Timber Framer’s Guild conference.  The tenon pictured above was a tenon with blind wedges.  As the tenon approached the bottom of  the dovetail shaped mortise, the wedges were forced into the tenon deforming it into the shape of the mortise.  This connection held close to 5000 lbs before the tenon was pulled out of the mortise.

The interesting part of this failure was the was how the sides of the tenon failed differently.  The grain of the wood on one side of the tenon was essentially vertical-grain between the wedge and the mortise wall verses the other side which was side-grain.  You can see that the side-grain example compressed, whereas the vertical-grain did not.

We will post the other two examples we entered soon.