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.
Buy a security bitset! It is surprisingly handly to have around. Sometimes, I’ve needed a certain screw size that they don’t have in imperial, but they do have in metric at the hardware store. But it’s a security bit only.
They also work on regular, non security bits in a pinch.
Comon, do some reading:
Phone camera; $30 digital microscope; $30 Endoscope. There are just so many better ways available to look down a hole to see what’s at the bottom than to tear apart the space around it.
Spanner bits are available in sets starting as little as $7. They are anything but “non-standard”.