lock nuts

[handinpants]

So I was putting another elbow, and I noticed that I was missing a copper 12mm lock nut, and I wanted to know if anyone knows a hardware store to get them?

Also it was really hard to loosen them, and tighten them, so I was wondering what some of you use to tighten bolts in cramped places?
I installed a elbow downpipe that is one piece

[Hawaiian240]

So I was putting another elbow, and I noticed that I was missing a copper 12mm lock nut, and I wanted to know if anyone knows a hardware store to get them?

Also it was really hard to loosen them, and tighten them, so I was wondering what some of you use to tighten bolts in cramped places?
I installed a elbow downpipe that is one piece


Try Lowes, and sometimes Advanced has them. As for the cramped space issue, I use ratcheting box end wrenches.