• joby@programming.dev
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        1 year ago

        It’s not. It’s 1.5" x 3.5". I don’t know the history and wasn’t able to find it in a quick search, but lumber sizes are usually a half inch less than the name would imply.

        That only applies to the thickness and width, though. The length of a board should be as described (e.g. a “two by four by eight” would be eight feet long, but have a cross section of 1.5 by 3.5 inches)

        • _Sc00ter
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          1 year ago

          It’s funny that you used 2x4-8 as your example for length, because a 2x4-8 stud is not actually 8 foot. If you’re looking for 8 foot 2x4, you need to be careful that you are buying true 8 foot boards, and not 8 foot studs.

          That being said, that’s the only board I’m familiar with that has a length that’s not always true length

        • Ddhuud@lemmy.world
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          1 year ago

          The story is that the wood used to be roughly 2x4 and by “roughly” I mean that the woodworker would have to throw away almost half an inch to even have a straight surface.

          But when the machines to do that became common the mills started doing that work, and they saved the extra volume of essentially garbage that was shipped with every piece of wood.

    • totallynotarobot@lemmy.world
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      1 year ago

      Nominal sizing is not uniquely American any more (if it ever was? Idk honestly). Work with lots of Europeans who are used to it as much as we are.

    • BilboBargains@lemmy.world
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      1 year ago

      As a legal requirement we don’t specify materials in anything other than mm, cm and m. In the UK the imperial measurements are sometimes also shown in a store, to help old people know what they are buying, but I’ve never seen that anywhere in continental Europe. Architecture isn’t drawn using imperial measurements, this system is used ad hoc by UK builders only. I like to torment these luddites by specifying in mm but mostly I avoid interacting with them because I don’t want to have a Mars Climate Orbiter situation at my house.