I hoard nuts, bolts, fasteners in general. Pop rivets, threaded inserts, self-tapping machine screws, cam-locks... Organized bins full of them. More than I'll ever use or need. Anything that could save me a trip to Lowes when I'm trying to work on something gets saved. 10mm bolts are worth more than gold sometimes. If I need 5 of any random hardware, I'll buy 10 just to have them if I need to replace them. You know the blister packs full of extra hardware you get when you buy cheap furniture or whatever else that needs assy? I break that **** down and assimilate the contents into my bins. If something breaks and I can't fix it, I scrap it for hardware. It's like an addiction and I'm only like that with hardware.