Tiny enough?

As I understand Holliegirl's theme for this week, it is a tiny thing which is normally larger.
The match is just to show the scale of the tiny ball bearings. None of those drills is larger than 0.5 mm.
What do I use them for? The short answer is that I don't, they were at the bottom of a "bargain bag" of 100 drills  under 2mm diameter, it was still worth it :-)