Wood that exhibits similar attributes such as character, length and milling tolerances are grouped together in a grade. The grades were established by the National Wood Flooring Association (NWFA) in conjunction with manufacturer associations to create consistency among different mills and provide the consumers and distributors with more defined expectations for their purchases. This instills confidence in all parties and helps to maintain fair pricing.
Keep in mind that sometimes grades are combined (Select & Better, Second and Better, etc.) or are a mix of two standard grades (No. 1 Common, No. 2 Common, etc.).
Mill Run (also known as Run of the Mill) is typically a mix of grades and has longer pieces. True to its name, this type of hardwood flooring is unique to the mill. This is an economical option for consumers and manufacturers alike.
Click through to read detailed descriptions and photos for each species: