asdfasdf wrote:
When using a nut, lock washer and bolt, should you also use a flat
washer between the object and the lock washer? I have seen it done
a million times that way but it seems the flat washer defeats the
purpose of the lock washer. I assume the lock washer is there
to dig in a bit to the object and the nut to keep it from
loosening. The flat washer seems like it would allow the
lock washer to rotate without digging in to the object.

Anyone know?

It all depends on what you're doing, what your fastening and why and if
you're doing is falling apart.

for high vibration use, where everything just rattles loose, Nordlock
washers seem to work pretty good. There seems to be magic resonant
frequencies where nuts and bolts just start to fall out, which can be
quite entertaining.