I don't know a lot about mechanical engineering, but at least in many aviation applications, the issue of nuts coming loose is resolved with a split pin that is

I don't know a lot about mechanical engineering, but at least in many aviation applications, the issue of nuts coming loose is resolved with a split pin that is bent into a locking shape after the nut has been tightened. http://www.technologystudent.com/joints/comnut1.htm http://www.technologystudent.com/joints/comnut1.htm Of course, this adds some extra overhead when disassembling the part, but the nut won't come loose unless there's a different problem (e.g. corrosion).