Class B locks are double row bullet slots. Super B grades are double bullets on one side and curved grooves on the other side. Some add a row of invisible bullet slots inside the lock cylinder.

- Mar 10, 2019-

Class B locks are double row bullet slots. Super B grades are double bullets on one side and curved grooves on the other side. Some add a row of invisible bullet slots inside the lock cylinder.


The anti-theft performance of Super B and B in these three kinds of safety door locks is much higher than that of A level. The technology opening time of A level is only one minute or less, and the destructive opening time is less than 15 minutes. The technology of the Class B lock is turned on for more than 5 minutes, and the destructive opening time is not less than 60 minutes. Super Class B lock prevents technical unlocking time of not less than 180 minutes and prevents destructive opening time of not less than 30 minutes. From a practical point of view, the A-level lock is anti-gentleman and not against the villain. The super-B-class lock is difficult to open and relatively safe. However, most of the safety door locks on the market are A-level, and the B-level cost is much higher.