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.
Just to add to your comment, the sell a smaller set for a few dollars less and also a “precision” screwdriver set that has some similar bits not but the full set. Both are very handy to keep around for this exact thing.