Grade B's mechanical lock-nuts I believe are rated for 3 removals (meets a min removal torque for three installs and and removals on the same bolt). Grade C's I believe are rated for 5. Aerospace flex type are like 15 removals.
What I hate is when a new component (like ball joints, tie rods, etc) that used a castle nut and cotter key is replaced with a lock nut. The factory torque spec goes out the window due to the added friction to overcome the locking feature.
