Why are those long planks of wood called “2 by 4s”?
What units are we measuring here? 2 what by 4 what? Regardless of what units were using the proportions seem all off. 2 by 4 seems to imply that its a rectangle where the longer side is twice the side of the shorter side, but that doesn’t describe this wood size at all. The long side is quite a big longer than twice the side of the shorter size. So I’m confused. Then there are other sizes of wood, like 2 by 6s, and I see similar issues there too.
Someone please explain what’s going on here.
The “2x4” name comes from the size of the rough cut timber when it is sawed out of the tree trunk. It starts as two inches by four inches. However, by the time the board makes it to the lumber yard, it has been milled down to 1.5 inches by 3.5 inches in order to remove bark, gashes, and other imperfections. Same thing with “2x6” boards or larger.
Now, this rule really only applies to building timbers. Other means of measurement apply if you were to go looking for, say, hardwood boards.
This is what I was taught as well. It’s a very intentional “not quite 2x4”, but saying that every time gets tiring haha