Working on the roof, several J-bolts appeared to have been fastened with more than a single nut. Without exception each such bolt was almost flush to the cement sheet.
I saw this done on a car wheel aeons ago; the original nuts holding the wheel were almost thrice as long as the four nuts.
- Is a bolt fastened to more than a single nut less likely to pop open?
- Is it better to use two nuts, rather than a single long nut on the bolt?