The anti-theft level of many commonly used MIM-lock cylinders can be divided into three levels: A-level, B-level, super-B-level, or C-level, of which super-B-level or C-level lock cylinders are divided according to enterprise standards.
The anti-theft effect of Class A locks is poor. The internal structure of this type of lock is simple, the marble grooves are few and shallow, and the mutual opening rate is high, which is easy to be broken and opened by others. According to the relevant national regulations, the anti-technical opening time of A-level locks is not less than 1 minute, the anti-abnormal opening time is not less than 15 minutes, and the mutual opening rate shall not exceed 0.03%, and so on.
The anti-theft effect of Class B locks is good. The internal structure of this type of lock is relatively complex. The lock cylinder structure mainly includes three types: computer double-row, double-row crescent, and double-sided blades. The mutual opening rate is relatively low, and the anti-technical opening time is long. It is not easy to be destroyed and opened by others.
Super B-level or C-level locks are classified according to enterprise standards. They also belong to the scope of national B-level locks. However, compared with national B-level locks, super B-level or C-level locks have a complex lock cylinder structure, usually a side post. Lock cylinder, its anti-theft technology has a long opening time and a lower mutual opening rate, and the anti-theft effect is better. Generally, the mutual opening rate of super B-level or C-level locks shall not exceed 0.0004%, and the opening time of its anti-technical technology shall not be less than 270 minutes.