Specifies visual grade requirements for select dressing and dressing grades for timber to be dressed; select engineering and engineering grades for engineering applications; and select merchantable and merchantable grades for scantlings. Approximate stress grade values are indicated for the four structural grades of Douglas fir and hemlock. Minimum off-the-saw dimensions are specified for a range of nominal dimensions. Notes on combinations of imperfections are included as is an appendix giving basic working stresses for the stress grades including compression perpendicular to the grain and shear at joints. The Standard recognizes the probability that pieces of Abies species, which occur naturally with western hemlock will be included in imported parcels.