@Rach1d well yea, ur right. But what i meant is how they manage to manufacture such thing in a few days. Running on concepts and how to manufacture it is two different things.
Well, I did learn some things reading mechanical design textbooks, and it ain't easy to design and manufacture a decent screw without the right tool and the available tech.
I believe ancient ppl might have invented concepts that we used in modern times. But alas the tech in their era might not advanced or inavailable to manufacture those things yet. For this case, i think for screw that small, u need complex machining tech to produce it which i assume that kind is nonexistent at the time. Also simple sand casting won't do cuz it would produce a lot of defects. 🤔
Tl;dr u can relate this with why howard stark left arc reactor blueprints to his son tony cause of inavailable tech at his time. 😁