Anti theft lock is divided into "general protection level" and "protection level". The former is indicated by the letter "a", while the latter is indicated by the letter "B". The so-called super-B and C-level locks on the market are defined by some businesses themselves, and they should be regarded as B-level locks strictly.

  1. For class a lock, the time to avoid technical unlocking shall not be less than 1 minute, and the time for avoiding destructive opening shall not be less than 15 minutes.

  Grade a lock is an old type lock cylinder. The key is cross plate type or crescent type, with convex key slot key, single side or double side has a row of concave key slot. This kind of key can be opened by thieves with tin foil in a few seconds. If you still use this kind of key in your home, you can change it quickly. Class a locks are no longer able to guard against thieves.

  2. Level B lock, to avoid skill unlocking time is not less than 5 minutes, to avoid impact opening time is not less than 30 minutes.

  The key of grade B lock is flat or crescent, and the key of grade B is more disordered than that of Grade A. the key slot is single or double sided, and there are two rows of concave or cylindrical multi-point concave key holes.

  3. Super class B lock cylinder, skill opening time more than 270 minutes.

  The key of super-B lock is flat type, and the key slot is single-sided or double-sided, with two rows of concave and S-shaped, or double snake type internal milling groove structure. It is a disordered lock cylinder and a safe lock cylinder. The opening time of the tool is more than 270 minutes, and even cannot be opened.

classification

  Grade A: the key is flat or crescent, with a row of concave or cross keyways on one or both sides, and convex keyways on all sides;

  Grade B: the key is flat or crescent, with two rows of concave keyways or cylindrical multi-point concave keyhole on one or both sides;

  Super grade B: the key is flat type, with two rows of concave and S-shaped keyways on one side or both sides, or double snake type keyways inside and outside.