Lumber conforming to this specification is intended for use in construction and repair of naval wood craft. The material is of a quality suitable for direct use, in full size, without further selection or cutting to obtain high grade pieces. Although cedar, mahogany, and Douglas fir are all used in ship and boat work, they are not necessarily interchangeable. Where drawings and specifications call for a particular type, that type should be used. In some cases, a particular species of cedar or mahogany may be required. It can be ordered specifically (see 6.2.1), conforming to the requirements specified herein for that type.

Grade A material is intended for use primarily as hull planking, decking, and ceiling, especially where forming to sharp curvature is involved.

Grade B material is intended for use as hull planking and ceiling where strength and curvature requirements are less severe and for structural members such as stringers and beams. The high quality and cost of these materials makes it inadvisable to use them for non-structural joinery and cabinetwork. For these uses, standard commercial finish and industrial grades of lumber are satisfactory and less expensive.