One of the fun things about technology is that there are so many diverse subfields that nobody can stay current with all of them. Occasionally, you come across a tool or process commonly used in another field that seems amazing to those not used to it.
One of the students where I work recently brought in a set of micro-sized drill bits. These are a fraction of a millimeter in diameter; the smallest chuck for my Dremel tool wouldn’t hold them. Even the drill bits for the LPKF PC board milling machine that we use are larger.
I don’t know what they’re generally used for (pilot holes for micro-sized screws?), but whatever it is, it involves extraordinary precision!
The set of micro-size drill bits. (Click for larger.)
A detail view of one of the smaller bits. (Click for larger.)
Thanks for sharing, Mike!
These bits are for a pin vise (aka hand drill, twist drill). It is and hand tool that looks very much like an exacto knife, except that it has a very small colette in one end. The other end usually contains a compartment with screw cap to store additional bits. They are used by hobbyists working with miniatures, models, doll houses, jewelry, etc. Hope this helps!