For at least 4 years, I'd been waiting for an opportunity to finally use a cotter key (AKA cotter pin, but ever since I started listening to
X Clan, I've had an obsession with anything that contains the word "key" in it). That, and I fervently enjoy making fun of people with body piercings by saying it looks like they were impaled with a cotter.
We had a situation with the gate where the nuts kept falling off. This was reminiscent of the time when I bought
my welder and was wheeling it home aside my bike when one of the wheels fell off. Whoever built that cart were idiots. On one axle, there was a locknut, which fell off from the wheel rotating. On the other, a castle nut WITHOUT a cotter key! = not protected by the red the black and the green, sissy! They also broke the rule of never welding on galvanized steel! Probably a good thing they sold me their welder for $20. I ended up finding the nut after retracing my path for about a mile.
The solution: castle nuts with the anti-rotation cotter keys. These particular keys are 1/8" which means drill an 1/8" hole in the bolt where it goes through. The actual pin diameter is less than the nominal of course.