I have a drafty door and attempted to install a door sweep like this. When I try to drill holes for the screws, nothing happens. I mean, I started with my power drill and a general purpose bit, but it barely made a small divot in the door surface, then the bit broke. I tried getting a nail and hammer and punching through the door, but I didn't even cause it any damage. I tried various other drill bits and self tapping screws, no effect, even after running the drill for several minutes.
I'm not a pro but I've done a good bit of building and diy before and have never not been able to put a hole in something before.