Comment by skolos

8 years ago

> If your screws are longer than 2”, you’ll need different ones, otherwise they will poke out the top of the board and stab you in the foot.

Actually nominal 2 inch lumber has thickness of 1.5" [1]. So your screws should be shorter than 1.5".

[1] https://www.archtoolbox.com/materials-systems/wood-plastic-c...

> Actually nominal 2 inch lumber has thickness of 1.5"

And, as I've recently learned, two-by-four is in fact 1½ × 3½ inches.

How on Earth does that make sense? Why do people call things as if they were X, while knowing perfectly well they're not X? Is this an American thing?

  • 2x4 lumber is cut into rough boards in the milling process which are actually 2 by 4. These are dried (at which point they shrink) and planed (the wood will warp a bit during the drying process, jointing and planing will help correct this) so the resulting boards are smaller than their original 2x4 size.

    Some more surprising detail in reality :)

  • 2x4 are 2x4 when they are rough cut. The ones you buy at a hardware store have been jointed/planed to the 1.5x3.5in size.