When you lose your key, or buy a second-hand house, rent a house or decorate it, you always need to replace the door lock cylinder. However, if you find an offline master to change the lock, the cheap price is more than 100 yuan, and the expensive C-grade lock may cost thousands of yuan.

Therefore, it is necessary for you to know how to buy safe and anti-theft lock cylinders.

Anti theft principle of the door lock cylinder

• Principle of a key unlocking

First of all, we need to understand how we use the key to open the lock cylinder.

There are always five pairs of marbles (red and blue cylinders) in the lock cylinder. The function of marbles is to jam the Yellow cylinder in the figure so that your lock cylinder can not be opened easily.

There are 5 blue marbles at the top and 5 red marbles at the bottom. The five pairs of marbles can slide up and down in their respective slideways.

When the key is inserted into the lock cylinder, the five pairs of marbles are pushed up to different heights by the toothed flower (uneven fluctuation on the key) at the corresponding position of the key.

If the key and the lock cylinder can match, the junction of the five blue marbles and the red marbles is just tangent to the cylinder that needs to be rotated when unlocking. At this time, the key drives the lock cylinder to rotate to unlock.

If the key and the lock cylinder cannot match, the toothed flower cannot push the marble to the correct height, and the Yellow cylinder will be stuck by the red or blue marble and cannot rotate.

• Factors affecting safety

The security of the lock is determined by the total number of the arrangement and combination of the toothed flowers of the key, and the type and number of toothed flowers are determined by two factors: the number of holes of the marble and the number of stages of the marble.

The number of holes in the marbles is the logarithm of the marbles. For example, the lock in the figure above is 5-hole.

The number of stages of the marbles is the number of marbles in length. Specifically, the sum of the lengths of the upper marble (blue) and the lower marble (red) remains the same, but the ratio of their lengths changes. Taking the above marble as an example, the length of the upper marble is not a continuous variable, but a discrete variable, which can only change with a certain minimum measure, such as 0.5mm and 1mm.

So, the total number of toothed flowers is:

the number of holes of the marble^{the number of stages of the marble}

For example, if the number of bullet holes of the lock cylinder in the figure above is 5 and the number of bullet stages is 4, its number of teeth is 4⁵= 1024.

The more toothed flowers, the better the safety of the lock cylinder.

How to choose a door lock cylinder?

⭕The number of lock cylinder blades should be greater than 36

The more the number of lock cylinder blades, the better the anti-theft performance.

The more blades, the more arrangement, and combination of toothed flowers, the less likely it is to be opened by technology.

⭕Idling Technology

Idling the lock cylinder can prevent the technology from opening, breaking the law that the unlocking tool can unlock as long as the lock cylinder is rotated. It can prevent drilling and prying. When the thief inserts the destruction tool into the lock cylinder, the force point cannot be found due to the idle rotation of the lock cylinder, so it cannot be opened.

⭕Material and workmanship

On the one hand, the material of the lock cylinder determines how much force it can withstand when it is opened violently. The test method is that the small magnet cannot be absorbed.

On the other hand, the more complex the key is, the higher the anti-theft coefficient is. It is only when the thickness is more than 2mm that it is strong and not easy to break.

In addition, the surface treatment of a high-grade lock cylinder is smooth without roughness. The key is inserted into the lock cylinder smoothly, and the middle gear of the lock cylinder does not feel stuck when the lock cylinder is rotated.

By the way

In the families of modern users, we can see the existence of smart door locks everywhere. The smart door lock can also change the lock cylinder.

If you need help, we are the professional alexa door lock supplier, plz feel free to contact us.