13-14.
Weiss, Howard, and Barnum, Charles T.: The prevention of sapstain in lumber.Cir.192, U.S.Forest Service, Washington, 1911, pp.

16-17.] CROSS GRAIN _Cross grain_ is a very common defect in timber.

One form of it is produced in lumber by the method of sawing and has no reference to the natural arrangement of the wood elements.

Thus if the plane of the saw is not approximately parallel to the axis of the log the grain of the lumber cut is not parallel to the edges and is termed diagonal.

This is likely to occur where the logs have considerable taper, and in this case may be produced if sawed parallel to the axis of growth instead of parallel to the growth rings.
Lumber and timber with diagonal grain is always weaker than straight-grained material, the extent of the defect varying with the degree of the angle the fibres make with the axis of the stick.