The larva is the main secret part of the castle, containing a special code. When choosing and buying a new lock, manufacturers leave it to the buyer to choose the larva for the locking mechanism. The purchase of a new larva is also necessary if the old one is broken or the key has been lost.

Parameters of lock larvae

First of all, you need to decide which larva is needed for the castle in each case. If, for example, for the larva in the lock there is a through groove in the form of a drop, the dimensions of which are: 34 mm in height, 10 mm in the width of the protruding part of the part, and 17 mm in diameter of the rounded part, then such a lock larva is made according to European standards DIN. When choosing a European standard larva, certain difficulties may arise. Of course, any larva is suitable for the castle, since they all have the same size. On the other hand, we have the widest assortment.

If the larva does not correspond to European standard sizes or has a different shape, then there is no particular choice, and only the same mechanism from a certain manufacturer will do. In the most extreme case, it may be a Chinese copy of very dubious quality.

Separately, it should be noted some models of locks from popular manufacturers from Israel - Mul-t-lock and SuperLock. These models comply with European standards and at the same time are equipped with a non-standard drive, which looks like a gear, not a cam. However, this does not pose any problem, since lock manufacturers supply their products with gear drives, so that for such locks you can safely choose a cylinder from any suitable manufacturer.

It should be noted that with the same cross-section, the length of the outer and inner parts of the cylinders may differ. In this case, the length of the inner part of the larva affects only the appearance of the part. The most important thing is that the end of the secret itself should not be hidden behind the decorative pad of the lock or door handle. As for the length of the outer part, it plays a more important role. If the design of the lock does not imply the presence of an armored lining, then the end of the larva must be strictly flush with the door strip. In this case, a small protrusion is allowed - no more than 3 mm.



The larger the protrusion, the easier it is for a thief to open the larva by destroying it with, for example, a conventional hammer. If there is an armored pad, then the end of the secret should be as close to its surface as possible.

Types of keys and the quality of the secrets of the lock larvae

The type of larva mechanism is most easily identified by the appearance of the key. For example, classic cylinder locks work with an English key. The blade of such a key is flat or curly, equipped with a serrated cut, reminiscent of a saw blade.

All locking elements are in the same plane. Almost all cylinder-type locks belong to the low-end product segment. You can buy an inexpensive larva that opens with an English key for those premises that are not exposed to a great threat of opening, or in the case when it becomes necessary to provide the key to the premises to strangers.



If the key has a cruciform shape, then such a lock is easy enough to break. Despite the fact that the cross-shaped key looks quite impressive, the secret of the lock contains only a few hundred combinations, which greatly facilitates the selection of the master key. In addition, the well of such a lock is quite comfortable and wide for the work of a master key. Such a lock will only help from "good people"; for professional thieves, it does not pose a serious obstacle. The Chinese are especially fond of making cruciform mechanisms.



A semicircular disk wrench for DIN standard larvae is quite rare, and the attitude towards such products is rather ambiguous. In the overwhelming majority of cases, these are very simple mechanisms with minimal resistance to hacking and an elementary secret. However, there are also very reliable products, mainly from the Finnish manufacturer Abloy. That is why such keys are usually called Finnish. If you decide to buy a mechanism of this type, then you should opt for Abloy products.



The most serious protection can be provided by locking mechanisms that are opened with a key-punched card. Such a key looks like a rectangular plate with a lot of grooves and grooves. The perforated keys are double-sided and inserted horizontally into the keyhole. Larvae of this type belong to the middle price category. It is almost impossible to open them by conventional means. To enter the premises, criminals use special equipment or try to destroy the lock or the door entirely.



Resistance of different types of locking mechanisms to opening

The highest quality and most reliable keys are made on the basis of special designs - punch cards. For reliability, manufacturers supply mechanisms with special magnetic or electronic recognition systems, combine different types of secrets. In addition to grooves and protrusions on the surface of the key, there may also be lateral teeth, various kinds of irregular grooves, etc. All secret elements are located with some offset from the vertical direction, asymmetrically.

For any key, you can choose a larva of suitable quality. If the mechanism of the larva is "sharpened" primarily for secrecy, then the materials from which all the moving parts of the lock mechanism are made are responsible for its service life. It is preferable that all the main elements of the castle are steel. If a manufacturer uses silumin, brass and other low-grade and fragile materials, this is a bad manufacturer and the quality of his products is corresponding.

Most buyers traditionally consider the level of secrecy to be the main indicator of the quality of the larva. But in practice, the very concept of "secrecy" is rather arbitrary.

It implies that the mechanism contains a number of mating elements that occupy a certain position necessary to release the lock from the lock.

The simplest and cheapest models have only 4-5 pairs of pins, the contact point of which must be strictly on the pivot line to ensure free rotation of the core. Inside complex and expensive devices, the number of pins reaches 12 or more pairs. In any case, the number of possible combinations is more indicative of the technical perfection of the castle than of its "secrecy", which depends, first of all, on the quality of work and the characteristics of the technological process.



Thus, the number of mating pairs of parts is of secondary importance, and the method of arrangement and arrangement of the pins relative to each other comes to the fore. The developers of locking mechanisms first of all try to complicate the task for burglars as much as possible - they make a keyhole of small size and complex shape, supply the lock with additional elements that interfere with the effective work of a master key, make false channels and moves, complicate the relief of contact surfaces, add the need to make an extra turn, and etc. - a separate article is needed to list all the methods of fighting against breaking locks.

Thus, even mechanisms with an average level of protection can greatly complicate the work of even the most experienced burglar - as a result, opening the lock will take a long time, if at all possible.

However, criminals are also monitoring the development of modern technology. Recently, the so-called bumping has become especially widespread. This hacking method does not require any special qualifications or prior training. You only need a set of special bump keys of different configurations. Such a key is inserted into the keyhole, slightly twisted to slightly tighten the mechanism, after which the attacker strikes the head of the bump key. From vibration, the elements of the secret of the lock are in the desired position, and the lock is opened.



You can provide protection against bumping with the help of special electronic or magnetic codes, as well as the installation of special cylinders without springs.

Sooner or later, the question of replacing the lock arises from almost any owner of an apartment or office. This happens when it breaks down due to a breakdown or loss of a key, due to the end of its service life, or when the tenant is changed. In most cases, the door lock cylinder is replaced, which is much easier than installing a new locking mechanism.

What is a castle larva

The mechanism responsible for the secrecy of the lock is called the larva, core or secret. It is she who is responsible for security, the possibility of unauthorized opening and penetration of uninvited guests into the premises. A key is inserted into the larva and turns. In this case, the pins inside it line up in a certain combination, and the lock opens. Incorrectly aligned pins, or pins, will not allow the locking bolt to move from its place, and the door, in this case, will remain closed.

In modern cylinder designs, pins are replaced by washers, rotating blocks, or moving probes. But regardless of the filling, the secrecy of the castle larva will depend on the number of components and the accuracy of their manufacture.

Not all existing locking mechanisms installed on entrance doors are partially replaceable; some locks have to be removed entirely. For example, code (lever) mechanisms are integrated directly into the body of the lock, so replacing the cylinder of the door lock in this case is impossible, you will have to remove it and insert a new one.

There are several types of the most popular locks for entrance doors:

• cylinder;
• disk;
• cruciform;
• pin;
• especially complex.

Locks for entrance doors can be overhead or more reliable - mortise, with a key-locking system on both sides, or with a turntable on the inside instead of a key. They are also subdivided into upper and lower ones, only with a locking function and with additional fixation by means of a latch. The material and the number of lock combinations depend on:

• reliability and the ability to resist mechanical stress;
• wear resistance;
• inadmissibility of matching keys.

The door lock larva is manufactured in three levels of secrecy:

• low - from 100 to 10 thousand combinations. Made of low-strength materials with a simple key profile;
• average - from 5 to 50 thousand combinations. It features a complex opening mechanism, but the quality of workmanship is not always at its best;
• the highest - from 100 thousand combinations to infinity. Manufacturing materials are of high quality, and the assembly accuracy is high.

Each of the locking mechanisms has its own design features, which determine the process and the possibility of replacing its larva.

Cylinder locks

A similar design of locks appeared in the middle of the 19th century. Due to the simplicity and ease of use, cylinder mechanisms quickly became widespread and are still the most in demand today.

Cylinder locking mechanisms are manufactured according to the European DIN standard or the RIM standard, which are now produced in small quantities. Larvae from different manufacturers of the DIN standard are practically interchangeable. Their choice depends on the thickness of the door leaf and the location of the fastening screw, in relation to the inner and outer plane of the door.

Cylinders can be subdivided:

• on the "key-spinner" system. From the inside, the door is opened using a rotary handle (turntable), which can be easily felt in the dark in case of an emergency or when the room is filled with smoke during a fire. Such a cylinder for a door lock has a movable cam, which transmits movement to the crossbars. Typically, its position requires adjustment in place;
• on the key-key system. The door leaf can be opened from both sides with a key. Such a secret is convenient when it is necessary to lock the door so that it is not opened from the inside by children or sick old people. In addition, the internal key inserted into the keyhole can be used as additional protection. It will be impossible to open the door from the outside;
• on a half-cylinder. The door can only be opened from the outside. A semi-cylinder is installed on doors in rooms where there is no likelihood of finding people. These can be small utility rooms or special buildings, for example, a weapons room;
• on the mechanism with a gear. The transfer of movement from the key to the bolt is more smooth through the gear, the number of teeth of which depends on the model and manufacturer.

It should be noted that the process of replacing such a larva with a gear is complicated, and only a specialist can help in this matter. To install a new cylinder, it is necessary to dismantle the lock with a similar mechanism as a whole.

Cylinders of the RIM standard are not found on sale as often as in Soviet times, and modern mechanisms of European manufacturers are not very popular. In this regard, it is rather difficult to find secrets for them. Their design resembles a half-cylinder of the DIN standard, with a difference in the method of fastening - the models in question are overhead.

DIY cylinder replacement

You can remove the unnecessary door lock larva, and then put a new one in its place. The process itself will take 15-20 minutes, no more. And from the tools you will need:

• construction tape;
• crosshead screwdriver.

First you need to find a screw that serves as a fastener for the larva in the general mechanism of the lock. As a rule, it is located on the key strip at the end of the door leaf. Its location can be symmetrical or asymmetrical in relation to the thickness of the door, depending on the model and manufacturer of the locking mechanism. Turning the screwdriver counterclockwise, the screw is completely unscrewed, and the larva is removed.

If the cylinder begins to move, but continues to "sit" in the socket, it is necessary to insert the key into the larva and turn it a few degrees in a clockwise direction.

Now you should pull the mechanism "towards you" or push it from the opposite side. The cylinder will easily come out of its nest. The fact is that a movable cam, or a flag present in its design, can interfere with the release of the larva, and a turn of the key will hide the cam in the cylinder body.

It is necessary to measure the total thickness of the door leaf together with the upholstery or insulation, if additional door cladding was made. In the absence of any changes, you can focus on the dimensions of the removed cylinder, which, of course, is easier. In order to determine which particular door lock cylinder you need to purchase, you also need to measure the diameter of the removed larva.

Don't forget the location of the set screw! It can be located both in the middle of the end, and be located closer to one of its sides. Moreover, with an asymmetric position, you should remember which of the distances is smaller - to the outer or to the inner surface of the door.

It would be more correct to take the removed cylinder with you when buying a lock cylinder. But if this is not possible, you should focus on accurate measurements. The color of the new mechanism will also play an important role in the choice, otherwise it will not look aesthetically pleasing on the door leaf.

The purchased cylinder is installed in the place of the old larva and fixed with a screw. The main thing here is to clearly get into the hole intended for its fastening. To cope with this task will help a slight stirring of the secret in the plane of the lock and its simultaneous baiting on the fastening element. In this case, the key must be fixed in the closed position. After that, the lock is checked for operability, first with an open door, and then with a closed one.

Opening and closing the lock should be smooth and soundless.

Disc locks

The main difference of these mechanisms from other cylinder locks is their design: instead of pins, or pins, there are movable discs that line up when the locking mechanism is opened at a certain angle. The key has a semicircular cross-section with cuts located on it corresponding to the position of the discs.

A design feature of the disk lock cylinder is the ability to replace it only with a "related" cylinder. But its purchase, at present, is difficult due to the fact that it is quite difficult to find a cylinder for a disk lock. Therefore, the best option would be to completely replace the locking mechanism.

Cruciform locks

In such designs of locks, pins are used, which line up along four faces inside the larva when the key is turned. Phillips cylinders have many combinations, but the lock can be easily opened with a Phillips screwdriver.

Pin locks

The larvae of pin cylinder locks are released under two types of keys:

• English;
• perforated.

In the first case, the lock is not particularly reliable, and the second can be opened only when the cylinder is drilled or knocked out, which is quite difficult and time-consuming. Replacement of the core of the lock is carried out according to the above technology.

Especially difficult locks

Manufacturers are constantly working on improving locks, primarily on their locks. Modern technologies make it possible to make unique mechanisms that are quite reliable and durable. By purchasing high-quality products of world famous brands, you can avoid the procedure of replacing the cylinder for the door lock. But this need may arise if the key is lost by one of the household or office workers.

Particularly complex locking mechanisms are used:

• armored inserts;
• titanium case;
• over a million combinations;
• refractory metal pins;
• floating elements on the key.

It is impossible to pick up the key to such a lock, but it is quite possible to replace the larva. True, it will cost a lot.

For reliable protection of your apartment, house or any other premises, our store in Moscow offers high-quality door larvae. They are presented in several versions - brass and aluminum. Do not forget that when choosing a door cylinder, you should be guided by the main color of the lock - there should be no differences in tone. We offer various color shades of the product:

• ... gold;
• ... chromium;
• ... nickel.

The secrecy mechanism of the presented products is different: there are both cylinder and lever versions.

Security Cylinder Mechanism

One of the most popular today. It is also called the "English castle". Its main element is a cylinder, which turns if it reads the code of only "its" key.

Leverage mechanism of secrecy

Such a lock is common for entrance iron, metal doors. At the heart of this type is a set of plates that, under the action of the teeth of the key, line up in a certain way and allow you to turn the mechanism and open the door.

Before you buy a front door lock cylinder, pay attention to its length and width, choose exactly the one that suits your lock design. The assortment of our store includes variations of both small and large sizes: 30/30, 35/35, 40/40, 45/55, 60/50, etc.

Also available:

1. 1) double-sided - both from the outside and from the inside, the door is opened with a key;
2. 2) with a turntable - the door opens from the inside using a special device - a turntable.
3. 3) for entrance doors;
4. 4) for interroom.

The set includes one to five keys for each door cylinder.

The price depends on several parameters: size, material, mechanism, manufacturer, and varies from 100 to 4000 rubles.

You can buy a larva for a door both in our store and by ordering them on the website or by phone in Moscow and Perm.

The lock cylinder is the coded part of the cylinder lock, which ensures secrecy and moves the bolts. It is due to the fact that the larva is inserted into the body and has an elongated oblong shape that it is called in the open-air "larva". A sort of steel embryo.

In fact, in the professional environment, the cylinder lock of a door is called a secrecy cylinder. Abbreviated as "CMS".

It is the correct name of this important part of the lock that we will use further in the text. But still, let's leave the "grub" in some places for better indexing;)

You can buy a cylinder or cylinder lock mechanism in a lock store. And to get a preliminary consultation - by the phones indicated above.

Quite often from the buyer we hear the phrase: "How can I replace the larva and what you need to know to pick it up"? The request has not been surprising for a long time: it is very difficult for an unprepared person to understand all the variety of secrecy cylinder mechanisms, their types, lengths and standards. In this article, we will consider the important parameters of the CMS and find out some of the nuances.

There are a lot of types of CMS. Let's start with the most common ones, which correspond to the European DIN standard (Europrofile) and which are used everywhere.

Here is what the buyer associates with the "door lock cylinder" in the first place:

Mechanisms of the Europrofile standard are produced in many countries: from China to Europe. The cost of a cylinder, depending on the model and manufacturer, can vary: from 150 rubles to 20,000 thousand rubles. The higher the quality and the more famous the brand of the mechanism, the more protective elements and innovative ideas are embodied in the lock cylinder, the higher its cost. For each model of a specific cylinder, you can write a separate material, for example, as a review article of the Slovenian CMS TITAN K56.

We will not stop here on any particular product, we will consider only the main parameters when choosing a cylinder.

Lock cylinder length and offset

We're sure you don't need to explain the calculation of the total cylinder length — it's the distance from one edge to the other. The required cylinder length is selected taking into account the thickness of the door leaf and on the basis of which cylinder lock you have chosen.

As we can see, the two parts of the cylinder are separated by a rotary cam. The cam width is always 10 mm.

The displacement of the cylinder is measured from the center of the mounting screw hole in both directions: outer and inner.

An equilateral cylinder is one in which both parts are equal in length. The versatile cylinder has different lengths for the same parts.

For example, below is a versatile English-type cylinder mechanism of Turkish production Kale Kilit with a total length of 71 mm. Often used on plastic doors.

Second example: a Chinese-made versatile cylinder mechanism with a total length of 90 mm. It is this size of the lock cylinder that is now popular on Chinese doors.

A cylinder of the correct length should not protrude much beyond the plane of the door leaf. If it is a wooden door, here the cylinder must be installed flush with the decorative strip or with the strip from the handle (up to 3 mm overhang is permissible). If an armor plate is installed on a cylinder lock, the length of the outer part of the cylinder will depend on the specific armor plate, on the method of its installation and on the specific door.

There are no fundamental requirements for the length of the inner part of the cylinder. But if on the inside the mechanism is also flush with the door trim or decorative strip, it will look aesthetically pleasing and harmonious.

Castle Larva with Pinwheel

For ease of operation, the cylinder of the door lock can have a rotary turntable. It allows you to open and close the cylinder lock from the inside without a key. At the same time, the turntable has no "blind spots" - in any position, the native key will always open the lock.

Equilateral Chinese cylinder mechanism 60 mm in length, with a rotating turntable from the inside:

Versatile Italian movement 72 mm long, with a swivel handle from the inside (the enlarged inner part of the cylinder is designed for the thickness of the inner door panel):

Other Cylinder Security Standards

If the cylinders described above are suitable for some standards, and can be installed in any cylinder lock case, then the following security mechanisms considered have other dimensions and fit strictly individually for one specific lock (or for some models of the same manufacturer). For example, the cross-type cylinder mechanism of the Turkish company "KALE KILIT".

Suitable only for locks of this type (installation in locks from other Turkish manufacturers (for example, FAYN) is possible, or with a slight alteration, under locks made in China (for example, 3M)).

And here is the domestic cross-key secrecy mechanism:

Suitable only for locks made in Kirov. And as you probably already understood, the Kirov movement cannot be inserted into the KALE KILIT case and vice versa.

For some domestic overhead locks, it is possible to purchase a cylinder separately. For example, the often breaking mechanism "FORT", which is suitable only for locks produced in the city of Petrozavodsk.

Locks of terrible quality, the mechanism of secrecy and the components of the lock are made mostly of silumin (a very fragile alloy), hence the frequent breakdowns and, of course, the availability of the opportunity to purchase a new cylinder! In the next photo, from left to right, you can see the cylinder mechanisms for the "Glazov" and "Iset" overhead locks.

Their problem is the same - soft materials and poor workmanship. Often these specific cylinders (there is no better quality cylinder to choose from) are ordered and manufactured in China.

If you need to replace the lock cylinder in Nizhny Novgorod, our service specialists are always at your service by phone + 7-987-110-30-43.

We will first find out what is right for you, we will guide you on prices and, after consent, we will send a master to you for a replacement.

The assortment of our company includes a huge selection of CMS. We sell both cheap Turkish and Chinese larvae and highly secret CMS from renowned European manufacturers. If, after reading the material, the castle larva still raises questions, we are always happy to advise you in the comments under this material.

Do you need a lock cylinder? Then you have come to the right place, contact our store, our consultants will help you make the right choice on favorable terms. The cylinder for the lock plays an important role for the door structure, because it allows you to reliably protect the door structure from intruders into the room. In addition, high-quality lock cylinders make the use of doors much easier.

Variety of models on the market

There is a wide range of various door larvae on the market, but not all of them are made of high quality, many manufacturers use unreliable materials and outdated technologies. Therefore, the choice of the larva for the castle with a turntable must be taken seriously. All our products are manufactured using modern equipment and durable elements, which guarantees excellent reliability and durability in use. You can buy a larva for a lock in a store quickly and profitably. The main advantages of our larvae:

• Verified, certified products of famous brands
• A varied choice for any kind of door
• Relatively low cost.
• Functionality and reliability.
• Delivery by postal services to any corner of the country



The larva for the front door lock is a structural element that is selected based on several parameters, we recommend that you pay special attention. It is recommended to buy larvae from producers that have passed the certification procedure. This guarantees quality, such larvae are reliable and practical to use. The locking mechanism will last a long time without replacement. Pay attention to what the lock cylinders are made of. The materials used in the manufacture of these elements are subject to increased requirements for reliability and strength. Therefore, the higher the quality of the material from which the cylinder mechanism is made, the more reliable the lock will be.

How to order

In our online store, you can choose a suitable model in the catalog, add to the basket and buy a lock cylinder for any type of door, wooden or metal, from the presented range of products. The simple and intuitive interface of the site greatly facilitates the selection and subsequent purchase. We offer products of such well-known brands. We have larvae of APECS, CALE KILIT, CISA, AVERS, Mottura, and other European and Asian producers. There are many models of larvae with turntables, symmetrical and reversible mechanisms of different security classes, and resistance to burglary according to Russian and European standards. When you contact us for the purchase of a turntable cylinder mechanism, you make the right choice.