Actualy, the term is most often used to describe the locking dogs that grip the shacklr to keep the padlock shut. The single locking mechanisms, as seen on Master No.3's, and combo locks, have a latch on one side, and are very easy to shim. The double locking mechanism, as seen on the bigger Tricircle padlocks use two locking dogs to secure each side of the shackle.
Not to be confused is double ball locking mechanism which uses ball bearings to secure the shackle - these cannot be shimmed.
That clear it up?
