Lock with a secret

In order not to mislead the reader, we must admit right away: the door that can resist burglary does not exist yet. But this does not mean at all that all heirlooms should be taken to the bank, and a pistol should be kept under a pillow in the bedroom. A “smart” lock is quite capable of restoring your calmness and confidence. CISA has developed a new model of the lock, which will create too many problems for the burglar, preventing all possible actions..

The main indicator of the reliability of the castle is considered to be it tamper resistance. The weakest is the castle, which can be overcome with a master key in 3-5 minutes. If he resists for 15–20 minutes, this product is a “C”. When a thief has to spend about an hour at the door, the lock is considered good. If the use of lock picks did not help open the door, and the thief took up the crowbar, we have an excellent copy. All types of locks are divided into five classes depending on the resistance to force impact, measured by time. If the apartment has something to profit from, it is better to get a lock of at least class III. This information must be contained in the product passport.


There is another criterion for the quality of the castle – its degree of secrecy. This indicator indicates the number of keys that need to be sorted out for the lock to open. There are two classes of secrecy: A – 25,000 key combinations, B – 100,000. There are, of course, locks with a security level of 1 million or more configurations. For comparison: the familiar English castle has an average of only 1000 combinations. Of course, attackers prefer to fight with locks of a high degree of secrecy by forceful methods – knocking out or drilling out a larva, or even the entire lock. To somehow secure the door, it is recommended to strengthen access to complex mechanisms with the help of special protective plates.


The design of each lock includes a secret and executive part. The secret or code part is a mechanism that learns the key or another version of the access password (a special card or the owners of the house themselves). And the executive is a locking mechanism arranged in all locks according to the same principle and consisting of crossbars (bolts), latches and slats. Depending on the method of installation of the executive part, locks are divided into mortise, overhead and inset and hinged.
MORTAL locks do not spoil the appearance of the door, although they are considered the most difficult to install. They somewhat weaken the strength of the door panel, and if some mechanism in the lock is out of order, it will not be easy to replace it..
Overhead locks are installed on the door panel, contributing to its appearance. But replacing a broken part will not cause trouble, and the strength of the door will not decrease.
INSERT locks are used only in steel doors. To install them, a hole is cut in the inner sheet of the door, where the lock mechanism is inserted. An opening also appears in the end profile, into which the crossbar comes out. This method weakens the door structure much less than when installing a mortise lock.

Different principles of the device of the secret part divide all locks into mechanical, electromechanical and electronic.
MECHANICAL, depending on the design, they are subdivided into cylinder, lever and code. Let’s try to briefly describe them.


Cylinder locks more familiar to us as English or French. The first models adorned the front doors of apartments back in the days of the Soviet Union. Then they were quite simple and resisted breaking with the help of a simple master key for no more than five minutes. Today the secret mechanism in them is a complex set of movable pins, plates or discs placed in a cylinder. The more pins, the higher the secrecy of the lock – to open the door, the key must line them up in a certain order. And they can be located both in one or two rows, and on three or four sides. The convenience of using a cylinder lock is that the larvae (also called cylinders) have standard sizes, and you can increase the degree of lock secrecy by replacing one cylinder with another, more complex one. The disadvantage of these locks is that the larva, making sure that the picking of the master key takes time, can simply be knocked out of the door. And the keys to such locks must be protected from mechanical damage – so that the key cannot line up the pins in the right order, a noticeable scratch will be enough.

Lever locks have a more ancient history: their ancestors guarded the dwellings of the ancient Persians more than three thousand years ago. The principle of operation is based on the interaction of levers – special plates. Once in the lock, the key puts the levers in certain positions, they move the locking bolts, and the door opens. The more levers and the more precisely they are made, the higher the degree of secrecy of the castle. Lever locks are more massive than cylinder locks, so they better resist both a master key and a scrap. But unfortunately, they are unable to achieve the same degree of secrecy. And their keys are more massive due to the design features. And this makes it easier for the burglar – picking up a master key in the presence of a wide keyhole is much easier. To increase the level of secrecy, manufacturers of lever locks equip them with transcoding units that allow you to change keys while leaving the lock itself in the door. There are also more ingenious devices: the lock, having no replaceable parts, can be recoded using the so-called “technical” key. It is inserted into the end part of the lock with only open doors and allows you to change the code settings in it. After that, it is enough to insert a new key issued by the same company into the keyhole, and you can not worry about the lost one the day before. At the same time, you should not worry that thieves outside will use the transcoding – this is impossible, since only the owner himself can change the lock code, having at least one original key.


Combined locks were born, thanks to the efforts of manufacturers to combine all the advantages of the above models in one case. As a result, two mechanisms, interacting in one lock, increase the degree of burglary resistance. Moreover, they can work both independently of each other and dependently. For example, mechanical action on the larva of one lock will automatically block the possibility of manipulation with the second. And the door panel, equipped with one lock, not two, will remain more durable.


Pump lock is also well known to the Russian buyer. A small wrench, inserted into the well with a spring force, acts on the pins located on the cylinder axis along the diameter. This lock combines the strength of a lever and the secrecy of a cylinder.

In addition to inventing all kinds of lock combinations, manufacturers are trying to protect each of the types presented from the encroachments of burglars, strengthening the weak points of the structure. So, protecting the cylinder from drilling, they use armored inserts and washers, as well as armor plates made of heavy-duty steel. In some models, the number of locking bolts is increased. To improve the characteristics of the lever lock, a special code strip is used, without opening which it is impossible to gain access to the main lock.



Locks equipped with additional rods to lock the door are very popular. Until recently, the most common among them was the so-called “crab” – a castle in which the rods were located on four sides. But practice has shown that if such a lock breaks when closed, then the entire door will have to be broken. Therefore, now manufacturers more often offer a modified model of a device called a deviator. In it, the rods are located in the upper and lower zones of the door lock end. The absence of the lower crossbar is compensated by the absolute “unreadability” of the crossbar location on the outside of the door.

ELECTROMECHANICAL AND ELECTRONIC locks have long deserved more attention from the consumer. The degree of burglary resistance does not differ from mechanical ones, and it is much more convenient to use. And you can install such locks in a hidden way, equipping with a mass of additional devices that will increase the level of security of the home. And the absence of a keyhole will keep the neighbor’s tomboy from the temptation to shove chewing gum in it. Access to a room with such a lock is possible with a special plastic card or, which is even more convenient, with a scanner and a computer, which identify the owners by voice, iris or fingerprint. There is one “but” in all this splendor: a power outage can leave you on the street for a while. Although, as experts say, it is quite possible to cope with this if there are autonomous power supplies..


Improving the lock systems, manufacturers still advise installing at least two locks on the front door. And, as the reader has probably already guessed, it is good if one of them is leveled, and the second is cylinder. But both are only of good quality. This can stop an attacker from figuring out how long it will take to tinker with different systems, and how many devices will be required! But it will make everyday life easier for you – in case of breakage of one lock, you can use the other while it is being repaired.
Another useful tip: when buying a metal front door, choose a lock first. Steel doors are becoming more and more popular, but we must take into account the fact that changing locks on them is far from the same thing that we are used to doing on the usual wooden ones. And if you are not ready to demonstrate the new door the capabilities of the welding machine, decide on the configuration of the locks before making a purchase..
The choice of the desired configuration of the lock is also influenced by the design of the door on which they will be installed. In order for the house to be reliably protected, the burglar resistance classes of both products must match. You understand that it makes no sense to reinforce the temporary door, which was built by the builders, with top-secret locks. Manufacturers recommend installing class III – V locks on solid entrance doors. It should be borne in mind that some locks are designed for use on metal doors, and some for wooden.

It should be noted that metal doors are becoming more and more relevant for modern homes. It is not surprising, therefore, that most of our recommendations are in one way or another addressed to the owners of just such doors. It remains only to briefly summarize how and how we can resist those who show an unhealthy interest in other people’s property:
1. It is better to secure the door with two locks (lever and cylinder), preferably supplemented with locking bolts.
2. Armor plate in the area of ​​the lever lock will prevent drilling of the mechanism.
3. The code strip will help protect the keyhole of the lever lock.
4. It is better to secure the cylinder mechanism with a mortise armor plate.
5. The lock area must be protected by a sheet of metal at least 3 mm thick.
6. If one of the locks does not open from the inside without the help of a key, the thief who got into the house through a window or other opening will have to start picking the lock..

In addition to this, it is recommended to consider possible cooperation with private security agencies. And then live in peace!

Rate article
Tips on any topic from experts
Add comment

By clicking the "Submit comment" button, I consent to the processing of personal data and accept privacy policy