It is well known that lumber is sold based on nominal sizes, and the actual size of the boards is smaller than the nominal size. The 4×4 size is based on the rough-cut size of the wood, before it is trimmed and planed to create a smooth surface.
What are the dimensions of a standard 4×4 or 6×6 wood post? The lumber industry defines standard wood post sizes as 4×4 or 6×6. The outside dimensions of the standard 4×4 measure 3-1/2″ x 3-1/2″, and the outside dimensions of the standard 6×6 measure 5-1/2″ x 5-1/2″.
Beside this, Why are lumber measurements wrong?
Maybe you’ve noticed that lumber sizes are often misleading. The “nominal” cross-section dimensions of a piece of lumber, such as 2 X 4 or 1 X 6, are always somewhat larger than the actual, or dressed, dimensions. The reason is that dressed lumber has been surfaced or planed smooth on four sides (called S4S).
Likewise, Why is lumber 1/2 inch smaller?
Lumber manufacturers typically cut a tree into the various standard types of dimensional lumber very shortly after the tree is felled. At this point, the 2 x 4 is actually 2 inches x 4 inches, a 2 x 10 is actually 2 inches x 10 inches, etc. … Hence, what started out as a 2 x 4 now measures 1 1/2 inches x 3 1/2 inches.
Also, When did lumber sizes change?
Early concepts called for rough lumber to be of full nominal size, often in the dry condition. After World War I, the increasing demand for construction lumber led to the first national size standard in 1924. This was revised in 1926, 1928, 1939, and 1953, while still another revision is proposed for adoption in 1964.
Why is lumber not true to size?
The “nominal” cross-section dimensions of a piece of lumber, such as 2 X 4 or 1 X 6, are always somewhat larger than the actual, or dressed, dimensions. The reason is that dressed lumber has been surfaced or planed smooth on four sides (called S4S). The nominal measurement is made before the lumber is surfaced.
23 Related Question Answers Found
Why are 2×4 not actually 2×4?
Now, most timber is milled and planed to give it a little more of a finished look, and a little more of a consistent size and profile. Because of this extra milling, a 2×4 no longer measures a full 2 inches by four inches. Instead, a 2×4 is really only 1 1/2″ by 3 1/2″.
Why are lumber sizes wrong?
Maybe you’ve noticed that lumber sizes are often misleading. The “nominal” cross-section dimensions of a piece of lumber, such as 2 X 4 or 1 X 6, are always somewhat larger than the actual, or dressed, dimensions. The reason is that dressed lumber has been surfaced or planed smooth on four sides (called S4S).
Why is wood half an inch shorter?
The 2×4 refers to the rough-cut green wood: it shrinks during drying, then the dried wood is planed smooth, so the finished lumber is supposed to end up at 1.5″x3. 5″. While it doesn’t really shrink that much, the mills get more usable finished 2×4’s from a given tree if they cut them slightly smaller to begin with.
Why is a 4×4 not 4 inches?
This pressured further compromise because thinner 2x4s were a way to compete in price with wood alternatives. Size standards, maximum moisture content, and nomenclature were agreed upon only as recently as 1964. The nominal 2×4 thus became the actual 1½ x 3½, imperceptibly, a fraction of an inch at a time.
What are the dimensions of a 4 by 4?
Nominal Actual Actual – Metric
——– —————- —————
2″ x 12″ 1-1/2″ x 11-1/4″ 38 x 286 mm
3″ x 6″ 2-1/2″ x 5-1/2″ 64 x 140 mm
4″ x 4″ 3-1/2″ x 3-1/2″ 89 x 89 mm
4″ x 6″ 3-1/2″ x 5-1/2″ 89 x 140 mm
How much load can a 4×4 post support?
The load capacity of a 3-foot #2 grade 4×4 is 17,426 pounds, and a similar 6×6 is 20,834 pounds or 16% better. However, an 8-foot 4×4 supports 6468-pounds and 2339-pounds at 14-feet, while a 6×6 is 18032 and 10550-pounds respectively – or 64% and 78% more load capacity.
Why is a 2×4 not 2 inches by 4 inches?
Now, most timber is milled and planed to give it a little more of a finished look, and a little more of a consistent size and profile. Because of this extra milling, a 2×4 no longer measures a full 2 inches by four inches. Instead, a 2×4 is really only 1 1/2″ by 3 1/2″. The same is true of pine.
Why are 2×4 half an inch shorter?
Now, most timber is milled and planed to give it a little more of a finished look, and a little more of a consistent size and profile. Because of this extra milling, a 2×4 no longer measures a full 2 inches by four inches. Instead, a 2×4 is really only 1 1/2″ by 3 1/2″. The same is true of pine.
How thick is a 1×4?
Nominal Size Actual Size
———— ——————————–
1 x 4 3/4 x 3 1/2 inches (19 x 89 mm)
1 x 5 3/4 x 4 1/2 inches (19 x 114 mm)
1 x 6 3/4 x 5 1/2 inches (19 x 140 mm)
1 x 8 3/4 x 7 1/4 inches (19 x 184 mm)
Why is lumber not actual size?
The “nominal” cross-section dimensions of a piece of lumber, such as 2 X 4 or 1 X 6, are always somewhat larger than the actual, or dressed, dimensions. The reason is that dressed lumber has been surfaced or planed smooth on four sides (called S4S). The nominal measurement is made before the lumber is surfaced.
What are the actual sizes of dimensional lumber?
Dimensional Lumber: Nominal Size vs. Actual Size
————————————————
Two-by-four or 2 x 4
Two-by-six or 2 x 6
Two-by-eight or 2 x 8
Two-by-ten or 2 x 10
Why is lumber not the actual size?
The “nominal” cross-section dimensions of a piece of lumber, such as 2 X 4 or 1 X 6, are always somewhat larger than the actual, or dressed, dimensions. The reason is that dressed lumber has been surfaced or planed smooth on four sides (called S4S). The nominal measurement is made before the lumber is surfaced.
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