I have taken up the hobby of restoring old watches. The screws used to hold watch movements together are quite small-some of them are 0.010" in diameter. These are really at the limit of what humans can handle-you must handle them with tweezers, and making sure that they engage properly is a pain (it is very easy to cross-thread them). Are there smaller screws made than this? I would think that handling screws mush smaller would be very difficult. Have really small ones been made by micro-machining?
Commerically, the smallest I can find quickly was 0-80 x 1/16" screws from McMaster-Carr (if they don’t have it, you don’t need it). That’s pretty darn tiny.
The smallest I’ve seen are from a model engine builder, but they’re not commerically available. He made them himself. I wish I had this guy’s tenacity.
It may be a joke, but at one time I was told this story.
The American engineers decided to do a one-upmanship on the German engineers, designed and created a functional drill bit of only a few microns thick, so small you had to use a microscope to view it. The Germans sent the drill bit back, with a hole drilled into it, and a screw threaded into the hole.
This site (with video) claims they make the world’s smallest screw. The size is 0.3mm, which is around 0.0118 in.
For the record, it’s a 20th century urban myth.