Plank flooring is a wide variety of hardwood flooring that comes in 4-in. to 7-in. widths. The thickness of the planks range from 3/16 in. to 1 1/2 in. The sides and end matches to fit tightly together and are screwed to a subfloor. Wooden plugs cover the screws. The best grades of plank flooring are free of character marks and wild grain. The finished strips of plank wood are more homogenous than strip wood flooring in the same species.