Flat grain lumber has been sawed parallel to the pith of the log and approximately tangent to the growth rings, i.e., the rings form an angle of less than 45° with the surface of the piece.
A piece or pieces sawn approximately parallel to the annual growth rings so that all or some of the rings form an angle of less than 45 degrees with the surface of the piece.
the wood is split or sawn with the annual growth rings.
Wood or veneer so sawed that the annual rings form an angle of less than 45 degrees with the surface of the piece.
Wood, which has been sawn across the growth, rings of a tree.