Well I'm building a table right now, and it was pretty easy to choose a size for a mortise and tenon in my 3/4" stock, a third of 3/4" is 1/4". If I wanted half its width, that's 3/8". Mental math is a lot easier than "What's a third of 19mm." In the wood shop, I rarely have to divide things by five or ten. I have to divide things by two, three and four a lot.

[–] Shareni@programming.dev 4 points 7 months ago* (last edited 7 months ago) (1 children)

I rarely have to divide things by five or ten. I have to divide things by two, three and four a lot.

I don't know anything about carpentry, so I'll take your word on it.

My best guess is that the standards are different. For example 2cm stock instead of 1.9. Then only the 1/3 is problematic.

[–] captain_aggravated@sh.itjust.works 3 points 7 months ago

I'm building a shaker table out of white oak. I milled all my stock to 3/4" thickness.

Just today, I resawed a board to 3/8", or half its original thickness. I glued two boards together to make 3/2" (1 1/2") thick table legs, and I cut mortises 1/3 the thickness of the stock, or a nice even 1/4".

I'm familiar with the metric system, I learned chemistry and physics in metric. I prefer woodworking in fractional inches because metric seems like a bigger pain in the ass