If you are new to buying softwood and hardwood lumber for craft projects or home improvement work, one of the first things you notice is that the dimensions by which the wood is sold (called the nominal measurements) are not the same as the actual measurements. Is the nominal measurement the same as the actual measurement? In other words, a board that is 1 inch thick, and 12 inches wide and long contains one board foot of hardwood lumber. One board foot is equal to 144 cubic inches of wood. Instead, suppliers generally sell hardwoods in a unit of volume known as the board foot. 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. The term dimension lumber is used with softwood species (such as pine or fir) that are used in the building trades for framing and other carpentry uses. In most cases, hardwood boards come in random widths to be ripped to size by the woodworker. In North America, hardwood lumber is usually specified using the quarter system, where a board is identified by its thickness in quarters of an inch.įor instance, hardwood trim that ends up being just over 1" thick (surfaced on 2 sides) is called a five-quarter (5/4) board. Surfaced refers to a finishing process that smooths the lumber to remove all saw marks. In the United States, softwood lumber is governed by the National Institute of Standards American Softwood Lumber Standard (PS 20). Softwood lumber is generally used for framing walls and floors.
The tables below provide both the nominal and actual sizes so many common North American lumber sizes. However, there is a difference between the nominal size (what the lumber is referred to) and the actual size. They reduce the number of injuries like unwanted splinters during the handling and manufacturing process and also ensure that the lumber stays looking its best all throughout until the customer sees it.2ĭimensional lumber is cut to a specific length, width, and depth. 6 days agoĢ×4 have rounded edges as it's very beneficial to the wood itself and those working with it.Actual SizeTwo-by-four or 2 x 41 1/2 inches x 3 1/2 inchesTwo-by-six or 2 x 61 1/2 inches x 5 1/2 inchesTwo-by-eight or 2 x 81 1/2 inches x 7 1/4 inchesTwo-by-ten or 2 x 101 1/2 inches x 9 1/4 inches4 more rows
What are the actual sizes of dimensional lumber?Ĭommon Dimensional Lumber SizesDimensional Lumber: Nominal Size vs.