| These fractions refer to the thickness of lumber and read in quarters of inches. For instance: four-quarters (4/4), eight-quarters (8/4), twelve-quarters (12/4).
4/4 lumber is sawn off a log for a 1" rough thickness. Since this is rough, the surface is not smooth or ready to be worked. At Woodworker's Source they surface on two sides (referred to as S2S or 'Surfaced two Sides'). Surfacing is done with a surface planer.
Rough lumber that is 'surfaced' does lose some thickness. Therefore, after planing lumber measures the following thicknesses: 4/4 = 13/16" 5/4 = 1-1/16" 6/4 = 1-5/16" 8/4 = 1-13/16" 12/4 = 2-13/16" |
