Basic blender went bad (motor ran but spindle wasn’t rotating). I wanted to disassemble to see if it could be repaired. Three of the four screws were Phillips head. I had to cut the casing open in order to discover why I couldn’t unscrew the fourth. It was a slotted spanner.
I had drill bits for such screws for decades, never had the reason to use them though. It’s nice to see that there’s a use for them after all!
Well, the drill bit wont fit if the hole is too long and thin, so its not always quite that easy.