wrote:
I will get a cheap tool chest to put them in, keep that ONE unlocked,
and pretty much let the neighbors help themselves when they ask to
borrow a tool... "

If they already aren't bringing back the ones that you personally hand
to them, what do you think will happen when you make it self service?
Instead of taking one thing, now they will feel free to take 6 cause
they might need them too.

I would have tried to make it less obvious that I have tools, by not
having them so visible to begin with. The answer to your problem is
already in place. When the guy that borrowed the 8MM comes back for a
new request, just butch up and say "Sorry, but I've been losing too
many tools lending them out and not having people return them, so I'm
not able to do it anymore." If you want, you can continue to lend a
tool or two to those that do bring them back. First time they don't
return it, cut them off.

Then you'll find out what kind of folks you're dealing with. If the
8mm guys is decent, you should have a new 8mm wrench within a few days.
My guess is you won't. And you're kidding yourself if you think there
is value in maintaining relationships with users like this. When you
need something, they won't be there for you, cause they don't give a
damn.