Originally posted by mertztr So here's another question I never bothered to ask anyone. How do lock washers work? What makes them lock?
For that matter, when should you use a wave washer?
When you tighten a lock washer it compresses. This compression puts an outward force on the nut. This outward force causes the threads on the nut and bolt to bind thus holding the nut in place. This is just what I think happens. I could be wrong.
What AgRunner just described was a 'wave' washer. Standard split lock washers follow the same principle, but add a 'biting' surface. When the nut tries to loosen, the edge on one side of the split bites into the nut; the edge on the other side of the split bites into the material below it. This keeps the nut from turning. Unless you can turn the bolt, the nut cannot be removed without damaging it or the other surface. Star lock washers have very little compression resistance. Instead they rely almost entirely on small tines which are alternately bent up and down. These tines bite into both the nut and the sub-surface, preventing the nut from turning.