Which direction experiences the greatest shrinkage in wood?

The direction that experiences the greatest shrinkage in wood is tangential. This is primarily due to the structure of wood fibers and how they are arranged in relation to the growth rings. Tangential shrinkage occurs along the growth rings, and since these rings are thicker and more pronounced in structure, they result in greater dimensional changes when wood loses moisture.

Wood is hygroscopic, meaning it absorbs and releases moisture from the environment, leading to changes in dimensions. The tangential direction, which runs parallel to the growth rings, shows the highest percentage of shrinkage because of the greater amount of cellular material within each ring. In contrast, radial shrinkage, which occurs across the growth rings, is less significant, while longitudinal shrinkage, which runs parallel to the grain, is minimal and often negligible.

A good understanding of these shrinkage patterns is crucial in aviation and woodworking, as they affect the stability and durability of wooden components used in aircraft.