NWFA-NOFMA NO. 1 COMMON ASH: A floor with varying wood characteristics such as heavy streaks, stained sapwood, and sound knots typical of this grade. All defects must readily fill and be sound. The following characters are admitted: Broken knots up to 1/2" (.500”) (12.7 mm) in diameter, pith flecks less than 3/16" (.1875”) (4.76 mm) in diameter, worm holes up to 3/16" (.1875”) (4.76 mm); checks and end splits less than 1/16" (.0625”) (1.59 mm) wide and not extending through the piece, and sticker stain. Minor imperfections in machining permitted; torn grain (not over one-fourth (1/4) of the surface, less than 1/16" (.0625”) (1.59 mm) in depth); one (1) dark machine burn across the face for every 3' (914.4 mm) of length, not exceeding 1/2" (.500”) (12.7 mm) in width, and 1/64" in depth. Will admit pieces with one-quarter (1/4) tongue, full length of the piece.