BIRCH FRAME grade boards provide structural grade boards for upholstery frame construction.
BIRCH FRAME grade, if selectively ripped, will yield a balanced number of long rails and shorter parts to construct a normal mix of sofa and chair frames.
Widths: 4 inch (101.60 mm) minimum.
Lengths: 72 inch (182.88 cm) minimum.
Minimum Size Cuttings: Minimum of one sound cutting 4 inches (101.60 mm) by 72 inches (182.88 cm). 4 inches (101.60 mm) by 24 inches (60.96 cm) structurally sound cutting.
Grade Notes: This grade admits all boards of 24 inches (60.96 cm) and over surface measure yielding not less than 66.66 percent structurally sound cuttings.
Cuttings will be reasonably flat and straight and, may contain bark pockets, season checks, slight surface shake that does not impair the strength of the cutting, firm tight pith and, stain.
Worm holes and other holes that do not exceed 1.5 inches (38.10 mm) in 4 to 5 inch (101.60 to 127.00 mm) wide cuttings and 2 inch (50.80 mm) in 6 inch (152.40 mm) (and wider) cuttings will be allowed.
Wane, as defined in WANE, is limited to 25 percent of the width and 50 percent of the length. Wane may be divided, showing on both board edges.
Side bend, as defined in SIDE BEND limited to 1inch.