Shake

Shakes are separation or cracks in the wood that occur along the grain, running parallel to the tree's growth rings. There are two types of shakes: radial shakes and tangential shakes.

Radial shakes occur along the radius of the tree and are caused by stresses in the tree resulting from wind or uneven growth. They typically appear as thin, irregular cracks in the wood.

Tangential shakes occur perpendicular to the radius of the tree and are caused by stresses in the tree resulting from changes in moisture content. They are often wider and more regular in shape than radial shakes.

Shakes can weaken the structural integrity of the wood and make it more prone to splitting or breaking. They can also make the wood more difficult to work with, as they can interfere with woodworking and finishing applications.