Larvae for door locks - the secret of the whole mechanism

For the secrecy of the castle meets the mechanism, which is called the core, sekretki or larva. Its main purpose is to ensure the safety of the home against possible unauthorized opening and entry of uninvited guests into the premises. Keys are inserted into the larvae for the door locks, which, when rotated, open and close the locks.

Types of secrets

Larvae locks can be very different.

The most common ones are:

• Cylinder. Differ in good degree of protection against unauthorized opening.

Such locking mechanisms are manufactured under the RIM standard, in limited quantities, or DIN European standard, the larvae of which from different manufacturers are practically interchangeable. Cores are selected depending on the thickness of the door leaf and the location of the fastener relative to the inner and outer planes of the door leaf.

The table shows the types and features of cylinders:

Cylinder system	Feature
	From the inside, the door is opened with a thumbturn or turntable. It can be easily felt in the dark in the event of an emergency or a fire when the room is smoked. In such a larva there is a movable cam transmitting the movement to the crossbars. Its position is required to be adjusted when installing the lock in place.
	In this case, the door leaf opens with a key from both sides. The secret is very convenient when you need to lock the door to prevent it from opening from the inside to sick old people or children. In addition, a key inserted inside the keyhole can be used as an additional protection. Open the door from the outside will be impossible.
	Дверь открывается только снаружи. Polucilindr устанавливается на двери в помещениях, где обычно не находятся люди. Это: небольшие подсобки или специальные постройки, такие как, оружейная комната.
	From the key to the bolt movement is transmitted more smoothly, using the gear. The number of teeth depends on the type of model and manufacturer. Tip: It should be borne in mind that replacing such a larva with a gear is quite difficult, and only a specialist can help. To install a new cylinder, you need to dismantle the lock with the same mechanism entirely.

• Disk drives. Their difference from other mechanisms lies in the presence of rotating discs in pins instead of them, which, when opening the locking device, line up at a certain angle. The shape of the key is a semicircular cross-section, with cuts placed on it, in accordance with the position of the discs.

Replacing the larvae is more difficult, their nodes are not as universal as the mechanisms of other types. In this case, it is better to replace the door lock completely.

• Cross shaped. This is not a particularly reliable option. Inside pins are located, sometimes you can even turn the usual screwdriver. To get to the larva, you need to completely disassemble the lock.

In the construction of locks used pins, lined up inside the larvae on four sides when turning the key. With a variety of privacy options, the cruciform cylinders in the lock can easily be opened using a phillips screwdriver.

Tip: It is not necessary to change the larvae on such mechanisms; the lock should be replaced completely. But in any case, it will require complete disassembly.

• Pin or English.

Such a larva in the castle can be:

1. English This is not a very robust design;
2. perforated, is opened only when knocking out or drilling a cylinder, which is quite difficult and long.

• Increased complexity. They are very difficult to crack, manufacturers make designs reliable and durable. Their price is more than usual, and you should not change the mechanisms with your own hands.

By purchasing high quality products of well-known brands, it is possible not to change the larvae in the door locks for a long time. This most often occurs when a key is lost.

In the most complex locking mechanisms are used:

1. titanium housing;
2. boulevard
3. a large number of combinations;
4. pins are made of refractory metal;
5. There are floating elements on the key.

It is impossible to pick up a key for such a lock, but it is quite possible to replace the larva.

Larvae secrecy

Locks for entrance doors can be:

• Overhead.

• Mortise, more reliable, lockable from two sides on the key or from the inside with a spinner instead of the key.

• Top.

• Lower, having only function of locking and additional fixing on a latch.

The material for the manufacture of the mechanism and the number of secret combinations determine their properties:

• Reliability and probability of resistance to mechanical stress.
• Wear resistance.
• The probability of mismatch keys.

Larvae for door locks can have three levels of secrecy:

• Low, with the number of combinations from 100 to 10 000. Made of low strength materials and a simple key profile.
• Medium, with the number of combinations ranging from 5,000 to 50,000 combinations. It has a complex opening mechanism, but does not have a very high quality performance.
• Higher, the number of secrets exceeds 100 000. They are distinguished by the quality of the materials used for manufacturing and high precision assembly.

Each larva of the door lock has only its inherent design features that determine the process and the possibility of its replacement.

Choosing a new secret

The quality of the secret node of the castle depends on the safety of property and the life of the structure.

When installing the lock from a well-known manufacturer, it will not be difficult to find the right node.

For this you will need:

• Check the compliance of the new mechanism with the dimensions and connecting dimensions.
• Pay attention to the quality of the material from which the larva is made.

Tip: Do not purchase the product from silumin. This is a very fragile and short-lived material.

• Brass, steel, aluminum or an alloy of aluminum with zinc are best suited for secrets.
• Savings are not always justified. A cheap mechanism can quickly break, which will spoil the mood and lead to additional expenses. It is known that the miser pays twice.

Reasons for replacing the larvae

It is clear that there is nothing eternal. The knots of the mechanism and its rotating parts gradually wear out. This process can occur smoothly, and sometimes a normally working lock suddenly became tight to open the doors. There are several objective reasons that lead to the replacement of the secret.

It can be:

• Node failure due to wear and tear during operation.

• Defects from improper attempts to disassemble the mechanism.

• Because of the mechanical impact on the door leaf.
• After opening the lock with tools at hand, when the key was forgotten at home (see How to open the front door without a key: if the need arose).

• When hacked by unauthorized persons.
• If you lose the key.

Timely replacement of the door lock larvae will save the door from damage, save the owner’s money.

Разборка и замена секреки

Before you take out the larva from the door lock, if it began to work poorly, you must first try to lubricate the internal components, including the secret. In this case, WD-40 fluid or conventional engine oil is used. If after that the lock works as badly, the larva will have to be removed and disassembled, as in the photo.

To remove and open the door of the larva, you will need: Phillips screwdriver and tape measure.

If a mortise lock is inserted in the door, the instruction manual suggests:

• Remove the middle screw of the mechanism.
• Insert the key into the well.
• Turn the key so that the larva freely pulled out.
• Save the screw.

Overhead door locks are removed completely. For this:

• The fasteners that hold the lock on the door leaf are unscrewed.
• Unscrew the two screws securing the larva in place.
• Screws are deposited neatly to the side.

In more detail the whole process of removing and disassembling the larva shows in detail the video in this article.

Installing a new bot

Before you change the larva in the door lock, you need to get it right.

For this:

• The total thickness of the door leaf with upholstery or insulation, if any, is measured.
• In the absence of changes, you can focus on the size of the cylinder to be dismounted, which is much easier.
• The diameter of the removed larvae is measured.

Tip: When buying a lock for an existing lock, you should take the cylinder removed. If this is not possible, you need to focus on accurate measurements.

• The new mechanism is selected in accordance with the color of the doors, otherwise it will not look very aesthetic.

To install the cylinder is necessary:

• Bought larva set in place of the former.
• Secure the screw, clearly hitting the hole, which is intended for its fasteners.
• A slight movement of the core in the plane of the lock will help bait it on the fastener.
• The key is locked in the closed position.
• The lock is checked for operability with the door open and then closed.
• The lock should open and close smoothly and silently.

Only high-quality larva for the door lock will provide reliable protection of doors against breaking and penetration of unauthorized persons.