The factory set combination for some Master Locks models is 0-0-0-0. This is the combination that some models of locks are set to before you remove them from the packaging and use them for the first time. \
You will change this combination when you use the lock, however, so if the lock has been used, it probably has a different code. \
You should always try the code 0-0-0-0 if you find yourself locked out of a combination padlock, along with 1-2-3-4, but if these guesses don’t work, you’ll have to reset the code or cut open the lock. \
A Master Lock combination reset is actually not as difficult as working with padlocks from other manufacturers, as this company offers an easy online form to help you retrieve your combination and sets reset tools for their locks. \