> How to assemble a lock the easy way

How to assemble a lock easily and quickly

It’s not that it happens frequently; But it does happen: we take apart an artifact and then we don’t know how to shape it to start it up again.

Cars, bicycles, watches, household appliances; nothing escapes this reality. It happens that when we think we have it, we realize that we have a couple of screws left over or we are missing a piece.

How to assemble a lock is one of these difficulties in which we are commonly involved; all for incurring in the lack of foresight at the time of disarming it.

In these cases it may happen that we disassemble the lock and then we do not know how to engage its components or that we disassemble it and then we cannot reinstall it correctly; it is also possible that both things occur.


Once we have disassembled the lock, whether it is mortise or superficial, we will find parts common to both that, even when they have different designs, play the same role in the operation of this implement.

What do we find inside a mortise lock?

When disassembling and disassembling a mortise lock, we find the following parts:

  1. The side plate (attached to the box) with two screws that fix it to the edge of the door
  2. The lid of the box, fixed with three screws.
  3. The box, inside which are:
  • Immovable pieces that act as pivots and serve as support for the springs and other sections of the lock.
  • The linkage lever.
  • Two pairs of combination plates with their four springs.
  • The double pass latch, located between each pair of combination plates.
  • The nut and a spring that keeps it pressed.
  • The slip.

The exposed enumeration tries to follow the order in which the lock was disassembled. It is always convenient, when doing a job of this type, to make documentation of each step we take.

Written notes, photos, drawings, voice notes or a video are excellent resources that will allow us to reassemble the device without problems.

Assembling a mortise lock

The assembly of the lock is a process that logically reverses what has been done before, that is, disarm it. If we have been cautious and keep notes of the steps we took, we only have to act in reverse now.

  1. To assemble our mortise lock we start by first placing the nut and the spring that supports it.
  2. Once the nut is fixed in place, the latch is positioned, taking care to leave the chamfer or curvature oriented in the same direction in which the door closes. Doing so will prevent the door from closing when pulled.
  3. The first pair of combinations and their respective springs are placed.
  4. On this first pair of combinations the double pass latch is planted, making sure that it is enclosed in the lock box.
  5. The remaining pair of combination plates are arranged on the safety latch.
  6. The linkage lever is accommodated.
  7. Between each of the pieces it is highly recommended to apply graphite powder as a lubricant; It is not advisable to apply oil and much less, eating oil.



The dirt-grease combination, when drying, can lock the lock after a certain time, for example, it prevents the combination plates from sliding with the freedom with which they should, when the key is operated.

  1. When everything is in place, the lock is covered with its cover, placing the three screws that secure it and proceeding to verify its proper operation.

Always, before reinstalling the lock, it is advisable to check that it is working properly. It may happen that despite all the forecasts, something has been overlooked.

Beware of combination plates

With regard to the combination plates, it must be taken into account that they are arranged inside the lock in an order that responds to the shape of the key, to the arrangement of its teeth and notches.

Any alteration that we make in the way the combination plates are arranged will prevent the key from operating the lock mechanism.

If we do not remember how these combinations were placed, the ideal is to mark each one with a number and test which is the correct position. This is a task that may take some time, but it is safe.

Numbered from 1 to 4, they are located in pairs, just as they were before disassembling the lock, without forgetting to place the security latch between each pair of combinations, and to try with the key.

An ideal way would be to start with combinations like 1234, then 2341, 3412; However, the truth is that we will probably have to face a real challenge: it is that there are 256 possible combinations.




Rim or surface locks

They are simpler than those of stuffing and to assemble them we proceed to:

  • Fix the drum to the lock box with two screws provided for this purpose.
  • A spring is placed at the base of the box to push the lower combination plate.
  • The first plate is located by making it fit into the corresponding pivots and the double-pass latch is placed on it.
  • A second combination plate is placed on this latch, which fits in the same pivots of the first.
  • The linkage lever is installed. This has a hole that engages a double pass latch pivot and goes through a slot in the latch shaft.
  • The cover of the lock is placed and it is fixed with a single screw that it has.
  • The device is tested to verify that it is working properly.
  • Once it is working properly, it is installed.

The same recommendations that were made for the mortise lock apply here: never use oil or any other type of grease; only graphite powder should be applied.

Ah, new technologies can help you to assemble a lock, get a mobile phone or camera and disassemble the lock, little by little, recording all the steps, then you will find that in the assembly, you have no doubts and make it perfect as it was. . It is the easiest way to disassemble and assemble.

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3 Ways to Open a Lock very easy

3 Ways to Open a Lock very easy

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