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submitted 3 weeks ago by mko@slrpnk.net to c/woodworking@lemmy.ca

I hope it’s not against the rules here, just saw this woodworking related xkcd that I enjoyed and thought it might be appreciated here:)

https://xkcd.com/3138

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[-] RougeEric@lemmy.zip 72 points 3 weeks ago

Have you hard of our lord and savior, the metric system?

[-] ILikeBoobies@lemmy.ca 16 points 3 weeks ago

We have but Canada sells so much construction supplies to the US that we don’t use metric for it.

[-] Nomecks@lemmy.ca 12 points 3 weeks ago* (last edited 3 weeks ago)
[-] BlueEther@no.lastname.nz 10 points 3 weeks ago* (last edited 3 weeks ago)

Even metric is under-sized on dressed timber 4x2" ~ 100x50mm => 90x45m dressed

[-] AvocadoSandwich@eviltoast.org 5 points 3 weeks ago* (last edited 3 weeks ago)

Yeah, but then we just use the 90x45mm as a measurement...

Also if I remember correctly it's sold as 89x44. 45mm was only used for I-joists

[-] Zwiebel@feddit.org 55 points 3 weeks ago

Wait 2×4s are not 2×4?? What is wrong with americans??

[-] Eq0@literature.cafe 39 points 3 weeks ago

They were 2x4 before drying the wood (that’s what I heard)

[-] ironhydroxide@sh.itjust.works 49 points 3 weeks ago

Not only drying, but sanding and straightening.

But in reality anymore they aren't even cut to 2x4 initially.

[-] panda_abyss@lemmy.ca 59 points 3 weeks ago

The hardware stores seem to pre-twist the lumber for you.

[-] dohpaz42@lemmy.world 33 points 3 weeks ago* (last edited 3 weeks ago)

Nah, it’s just they buy wet wood and it twists as it dries. Also, places like Lowe’s likes to stack a lot of wood vertically, so they get that nice bow in them for all those rocking chairs people want to build.

[-] Zwiebel@feddit.org 1 points 2 weeks ago

Lot's of rocking chair supplies in Europe too :/

[-] bluGill@fedia.io 9 points 3 weeks ago

You heard wrong. They use excuses like that, but truth is they can make the final size anything they want, for many years every different sawmill decided their own final size. You start by cutting wet wood to a size, you might or might not dry it, then you plane it down to an exact size. Some sawmills started by cutting to 2x4 and then planning different amounts off. Others cut bigger so when they planed it down they finished with 2x4. Everyone did something different and so if you bought a 2x4 you better pray that sawmill remains open for when you want to remodel and need more. Eventually enough people got sick of this and decided to make a standard, the current measurements are what was decided, it was arbitrary, but at least everyone follows the same standard so you can buy from different sawmills. Exactly 2x4 is also arbitrary.

[-] Carvex@lemmy.world 19 points 3 weeks ago

Anything to fuck us out of our money and quality products a little bit harder.

[-] excursion22@piefed.ca 17 points 3 weeks ago

The American way.

[-] ArsonButCute@lemmy.dbzer0.com 15 points 3 weeks ago

They are until they're planed to smooth them, at which point they are approx 1.5" x3.5"

[-] KingOfTheCouch@lemmy.ca 10 points 3 weeks ago

Just like 50x100's are usually more like 40x90's, or something even more insane - 39x86? Like I'm sorry, but the unit of measurement is NOT the problem, it's the centuries old "traditions" and "standards" to normalize dimensional lumber that are the problem.

At any rate, one should look at the names of boards as the ratio of their dimensions and leave the inches and mm out of it and it starts to make more sense.

[-] Zwiebel@feddit.org 1 points 2 weeks ago

They always have the exact measurements here like 200 x 5,8 x 3,8 cm

[-] CompostMaterial@lemmy.world 8 points 3 weeks ago

2x4 is the rough cut not the finished cut that is sold in the store. If you shopped at a proper lumber yard, you can usually get rough cut lumber if you want to finish it yourself.

[-] Skullgrid@lemmy.world 8 points 3 weeks ago

you know what, fuck that name. how about you dicks call it something better?

[-] litchralee@sh.itjust.works 5 points 3 weeks ago* (last edited 3 weeks ago)

Although I suspect this particular quirk of dimensional lumber stems from the British, the result is not too unexpected for modern-day America. After all, we (insanely) deal with sales tax the same way, where the advertised price is pre-tax, and consumers have to do math if they want to compute the final bill before reaching the checkstand.

So having to measure the lumber to acquire its actual dimensions is entire above-board [pun intended] for anything beyond putting together a wood-frame structure.

[-] AMillionMonkeys@lemmy.world 22 points 3 weeks ago

Lee Valley used to sell a blank tape measure, for pure, real-valued metrical madness.

[-] thenextguy@lemmy.world 13 points 3 weeks ago

Can I get some dimensionless lumber?

[-] badcommandorfilename@lemmy.world 10 points 3 weeks ago

Best I can do is interdimensional lumber

[-] NaibofTabr@infosec.pub 13 points 3 weeks ago

Except that all of the board length measurements will not work out.

[-] Darkassassin07@lemmy.ca 7 points 3 weeks ago

A nightmare if you're following written measurements or working with other people, but as long as you use the same tape to measure how much you need and how much you have/are cutting, it should work out alright.

[-] Placid@lemmy.world 6 points 3 weeks ago

Unless you're building anything with speced sizes . Oops I framed the walls too short.

[-] Darkassassin07@lemmy.ca 5 points 3 weeks ago

That would be the following written measurements I mentioned.

[-] MadMadBunny@lemmy.ca 7 points 3 weeks ago

Damn creative measuring.

[-] BlindFrog@lemmy.world 7 points 3 weeks ago

I reflexively cringed with my whole face seeing "lumber" and "measure" in the same sentence.

Look up what the fuck Board Feet is. Then imagine trying teach other people how to measure for board feet. Then imagine everyone misremembering and misinterpreting how to do it.

Fuck board feet.

[-] OhioComrade@lemmy.ml 5 points 3 weeks ago
this post was submitted on 30 Sep 2025
318 points (100.0% liked)

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