[Solved] Removing Broken Screw from Small Elements: Techniques for Tiny, Delicate Items

My experience: an M6 broken off when tightening. First of all, a very good quality metal drill bit. I drilled with one for 10 zl, but when I bought one for 20 zl, it only made sense. I used a diameter of 3.0, but it is minimally too much. I think 2.5 would have been ok. The second thing is that you need to drill as centrally as possible, so that the screwdriver has something to grab onto. Third, you need to drill a minimum of about 0.5 cm so that the twist-off has something to grab onto. Fourth, the twist-off with a slanted thread, as in the photo, rather than with a straight thread, which clasped worse and quickly began to spin. Both bought at the market for $20. With these parameters, I used the second largest screwdriver, because the smallest one, however, was too small. You have to take it easy, a lot of space and a lot of time.

Błażej wrote:

The author has written as many as two posts in the thread and has been silent since April. Maybe he turned that screw long ago? And here you continue to combine. If the author does not speak up in the thread, the whole thing will fly in the trash, as a scolding of foam about nothing.

Interaction of the founder of the thread is probably not necessary to give expert answers and the author has the right to remain silent. So rather everything for now is in accordance with the rules of procedure.
I don't know what the author's proclamation is needed for? Consider that he has already unscrewed this screw, or that he will unscrew as once read these ideas - indifferent.
I myself learned from this thread many interesting ideas, and the caravan goes on.

For me it seems most sensible, slightly stretch the clamp and then you can file two planes under a 6 or 7 key and try to unscrew.

The bolt was reamed with a small drill bit on a bench drill.