[ACHiPo]

Originally Posted by Jaydee

Spring washers seemed like a good idea many years ago, but proofed to be so wrong. Under severe torque it can spread apart and loosen the nut. You won't see any manufacturer use them anymore. Just flat washers if any, and no lock nuts either. The best idea I've seen were 2 washers with opposite micro ramps that, if any vibration tried to undo the nut it would actually tighten itself.
I still like nyloc but never use a impact gun to tighten them.
JD

JD,
I think you’re describing Nord-Lock washers—by far the best locking mechanism for high vibration and heat. They come in a variety materials for hostile applications.
Nord-Lock Group | Secure and Innovative Bolting Solutions