This is the simplest and quickest way I found to permanently, physically destroy compact flash cards. It will work for pretty much any external flash card.
These CF cards have been sitting around for quite some time. I long ago got rid of the reader to an electronics recycling event. I’m sure there’s personal data on there. Oops. So I needed to physically destroy them. I’m not worried about James Bond, just the neighborhood dumpster diver.
Tools: 1) Vise, even a small one like mine will work. 2) Some sort of cutting tool. 3) Pliers.
Insert the CF card lengthwise in the vise:
Compress the card until it breaks apart.
Sometimes, the covers come off easily by hand. On other cards, I used pliers to remove them.
Use your cutting tool to cut the memory chips into as many small pieces as you are paranoid.
Put the memory chip pieces in the trash, burn them in your fireplace, distribute them among several public trash bins. How paranoid are you?