I often wonder if these parts are important, what part of the train do they fall off, and do they pose a danger to the public.
Obviously a lock washer was made to hold a nut tight. If the lockwasher has come off on the tracks, then the train has lost a nut somewhere.
I also find huge machine bolts that have come off the train, and other bits of unidentified pieces and parts of a train. If I let myself ruminate about it too long, it could get scary. After all, a normal car, truck or transport trailer doesn't shed bits on the road. Why should a train?
I also find a lot of discarded rail spikes as well, but that is a different story. They are not train parts.