It’s from a time when you bought undried and planned wood rather than dried and planned like we typically do now.
It’s less a quirk of the imperial system and more a quirk of the lumber retail system, which is older than the metric system.
The biggest difference is that in places that use dimensional lumber and the metric system the pattern is to sell by actual dimension, rather than nominal. So a wall stud might be 45mmX145mm, or 63mmX75mm for a rafter, depending on your country.
Most north American hardware stores also sell by finished sizes now.
limer@lemmy.ml 3 weeks ago
harrumph…
Those nonsensical rules exercise the brain more. Helps stave off mental deterioration.
Carpenters in the USA have a higher mental acuity at advanced ages than scientists
captain_aggravated@sh.itjust.works 3 weeks ago
Frankly, using a base 12 measurement system solves more problems for a woodworker than a decimal system does. It works very well for the task of woodworking. I’m familiar with and use the metric system for other things but I’m never building furniture in centimeters.
Capricorn_Geriatric@lemmy.world 3 weeks ago
Genuinely curious. Mind giving an example?
captain_aggravated@sh.itjust.works 3 weeks ago
Okay, a simple mortise and tenon joint. If I cut my board to 3/4" wide, if I want a tenon that is half the width of the board, it is 3/8" with 3/16" on either side. All my tools have these markings, I have router bits and such that are these sizes, easy. If I want a tenon that is 1/3 the width of the board, that’s 1/4" with 1/4" on each side. Also quite easy to find tools for.
In metric land, they often mill wood, or manufacture plywood, to 19mm. Because that’s quite close to 3/4". Show me a half, or a third, of 19mm on a metric tape measure.
You’ve got a 4 foot cabinet with 3 doors in it. How wide is each door? 1 foot, 4 inches. You’ve got a 400cm wide cabinet with three doors, how wide is each door? 133.3333cm.
WalterLego@lemmy.zip 3 weeks ago
Maybe they just measure their age wrong.
limer@lemmy.ml 3 weeks ago
I don’t think so, they are all 6 doggers old or more