Larry Williams
"Stability," in the forest products industry refers to the ratio of shrinkage between the tangential and radial directions. This means when drying the wood shrinks more in the flat sawn direction than in the quarter sawn direction. That's it, nothing more. It has little to do with the ability of the wood to stay in place or keep its shape once dry. For its density, beech has a relatively small amount of seasonal movement in the radial direction. This is used to advantage in plane making because the grain is oriented so that the wedge is housed in the radial grain. Large seasonal movement is a problem for maintaining the angles necessary for a secure wedge in a plane and beech's relatively small changes in the quarter sawn orientation make it ideal for planes.