
Nominal lumber sizes us. The reasons why the nominal dimension of this lumber what the lumber is called is larger than the actual dimensions involves historical practices in the lumber industry. Board foot a volume measurement of lumber 1 board foot is equal to 144 cubic inches to calculate multiply width in inches x length in inches x thickness in inches. 1a6 34 a 5 12. If your project calls for precise measurements be sure to check your lumber before purchasing.
The tables below provide both the nominal and actual sizes so many common north american lumber sizes. Commercial standard lumber sizes table chart. The actual size is always a little bit smaller. Dimensional lumber is available in green unfinished state and for that kind of lumber the nominal dimensions are the actual dimensions.
Dry lumber that has been seasoned or dried to a moisture content 19 or less and green lumber has a moisture content of greater than 19. Here are the common sizes of lumber and their actual sizes. Lumber sizes are usually given in aoenominala measurementsthe nominal measurements are a boards size before it has been planed. When the board is first rough sawn from the log it is a true 2x4 but the drying process and planing of the board reduce it to the finished 15x35 size.
Dimensional lumber is cut to a specific length width and depth. 2x4s are not actually 2 inches by 4 inches. Grades and standards edit the longest plank in the world 2002 is in poland and measures 3683 metres about 120 ft 10 in long. After the board is dried and planed it becomes its actual size of 1 12x3 12.
1 x 6 34 x 5 12 19 x 140 mm. Department of agriculture summary lumber size standards came into being almost a century ago to meet the need for a common. When a 24 is cut out of a log it is 2x4. Lumber sizes are usually given in nominal measurements.
The label put on the lumber you buy is called the nominal lumber size. Wood engineer 2 forest service us. Smith wood technologist 1 and l. The actual measurements are the final size.
The nominal measurements are a boards size before it has been planed smooth surfaced on all 4 sides. Originally a 2 x 4 was cut as a rough green board that was exactly 2 x 4 inches in size but by the time the boards were dried and planed the boards became smaller approaching the now standard 2 x 4 dimensions of 1 12 x. Lumber dimensions the actual sizes of common lumber sizes2x4s are not actually 2 inches by 4 inches. Nominal refers to the dimension the lumber was sawn.
However there is a difference between the nominal size what the lumber is referred to and the actual size.