a sound knot that is not greater than 1.5 in (3.81 cm) in diameter (with hardwoods not greater than 1.25 in or 3.18 cm in diameter) —note the diameter range includes a pin knot at not greater than 0.5 in (1.27 cm), a small knot at not greater than 0.75 in (1.90 cm), a medium knot at not greater than 1.5 in (3.81 cm), and a large knot at greater than 1.5 in (3.81 cm) This definition last updated 10/14/2008