There has been a flurry of discussion lately about the actual sizes of wood and wood products, started by an article about a lawsuit in which a customer is suing a major vendor because their 2x4s were not actually 2” x 4”.
This is silly enough that it might work for the plaintiff but it’s nothing new to anyone who has used these products on a daily basis. We have not seen a 2” x 4” 2x4 in close to a century.
Wood products manufacturers have long used the term nominal dimensions to explain the shrinking 2x4 phenomenon, claiming that the wood is cut to 2” x 4” but is smaller once the surfaces have been smoothed. Anyone who has ever prepped their own lumber knows that you rarely need to remove 5/8” of material to get smooth faces. We all realize that this is more to allow a larger yield and have come to accept it. After all, plywood does not need to be processed in the same way as solid lumber and when was the last time we saw a sheet of 3/4” plywood that was actually a full 3/4” thick?
An interesting contrast is in the sizing of sheet goods intended for cabinet production. These goods are often an inch oversized in both dimensions. A 4x8 sheet will measure 49” x 97”, allowing full 2’ wide cuts and leaving sufficient material for end trimming. Odd in a way because a 2' deep base cabinet does not require a full 2' wide side or deck since deductions need to be made for backs, hanger strips and facings.
Maybe they got it backwards?