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Lock washers are utilized to secure lock nuts. A tab washer is the most common type used in industry. Tab washers contain an internal tab which fits into a shaft keyway. The washer also contains external tabs that fit into slots located on a lock nut. When the lock nut is fully tightened, and the internal tab is properly positioned, one of the external tabs on the washer is bent over into one of the locknut slots. This prevents the locknut from backing off as the shaft rotates.