I have ~10 HDDs that I’d like to dispose of. For a while, I tended to buy unwarrantied used disks for my NAS, so these have all failed in some form or another over the years. I can’t just toss them, because they have my (unencrypted) data on them, but I can’t wipe them either since they don’t mount anymore. I want a simple and reliable way to render the contents unrecoverable. A nation state is not part of my threat model, but any kind of data reconstruction that could be bought with civilian money is.

I’ve tried:

• Smashing with tools (largely ineffective)
• Punching holes with a drill press (how many holes are needed to ruin the disk? Also I’ve broken/dulled a few bits doing this)

Edit: Disassembly doesn’t seem like an option, I’ve removed every screw I can find and any sticker or PCB that might be covering other screws. The top cover seems to have been pressure fitted or spot welded on. There’s not even the tiniest gap to pry open.