We install door handles with our own hands. How to install a door handle on an interior door - we can master any mechanism Door handle with a lock how to install

We install door handles with our own hands.  How to install a door handle on an interior door - we can master any mechanism Door handle with a lock how to install
We install door handles with our own hands. How to install a door handle on an interior door - we can master any mechanism Door handle with a lock how to install

It is difficult to imagine how to use an interior door without such a mandatory attribute as a handle. At first glance, its installation may seem complicated. However, if you take the task seriously, have the necessary tools and materials, and properly organize the work, you can handle the task yourself. In the material presented, we will consider how to install a handle on an interior door.

Types of handles

There are several types of handles that are suitable for inserting into an interior door:

  • rotary;
  • with a push mechanism;
  • without locking mechanism.

Stationary handles, which do not have a mechanical part, allow you to open the door under the influence of pull. As for push-pull systems, the latter have a lever-style shutter. In the process of pressing such a handle, the lock tongue moves inward, which allows you to open the door.

What is a lock for an interior door with an oval handle? Installing such a system allows you to open the door without pressing the lever. Thanks to the round shape of the handle, the operation is carried out by turning the holder. The design may include a locking button, which allows you to fix the tongue of the locking mechanism. This way you can lock the interior door from the inside.

Tools and materials

What does installing handles on interior doors require? During self-installation, you may need the following tools:

  • pencil;
  • a hand or electric drill with an attachment in the form of a feather drill;
  • screwdriver;
  • chisel for woodworking;
  • hammer.

Interior door handle installation height

Before inserting a lock into an interior door, you need to decide on the optimal location for placing the handle. To do this, it is enough to simulate the opening of a door, think about what height is most acceptable for each individual user. As practice shows, the right solution is to install the handle on the interior door at a distance of at least 1 meter from the floor plane. The presented footage looks optimal for both adults and children.

Cutting a hole for the handle

Having found the necessary tools and decided on the location of the structure, you can proceed directly to creating an opening for mounting the mechanism. First, you should mark the height of the future handle on the door plane and its end part. This is required to determine the exact location where the opening will be made for the double-sided structure.

In order not to make mistakes in the calculations, it is enough to take the latch mechanism, and then use a tape measure to measure the distance from its eye to the visible edge. The parameter must be marked at a pre-selected height on the door leaf. Once the appropriate markings have been made, you can proceed to selecting a suitable bit for drilling holes.

Having made the openings of the required diameter on the plane and the end of the door leaf, here it is necessary to attach the opposite parts of the handle structure. If the thickness of the plane does not allow assembly of the product, excess wood should be removed using a chisel. Next, you need to strip the canvas on both sides until the handle fits tightly into place.

Latch installation

After all preliminary work has been completed, it is necessary to position the latch in the prepared hole. handles on an interior door involves screwing it to the door leaf in a prepared opening using fasteners that are included with the product. It is convenient to carry out the work using a screwdriver. However, if the latter is not available, you can use a regular screwdriver.

After strengthening the locking part of the structure, a core is built into it, which is strengthened thanks to the screw, long part. To avoid problems with installing the core, you must first insert the key into it by moving the locking tongue of the mechanism to the closed position. Only then should you tighten the screw.

Installing a door handle on an interior door

Directly introducing the handle into a previously installed structure is the simplest stage of the work being done. Here it is enough to insert a square-shaped rod into the corresponding opening of the locking mechanism.

The next step is to fix the handle with fasteners on one side of the door. To do this, you can use self-tapping screws or use zip ties. As soon as the first handle is successfully installed, it is necessary to perform similar operations with the other part of the structure, which will be placed on the back side of the door leaf. In this way, a connection will be established between both elements of the system.

Installation of a plate for inserting the lock tongue into the door frame

In order for the installation of a handle on an interior door to be considered complete, it is necessary to make a corresponding hole for the locking part of the locking system to fit into the door frame. To prevent errors in calculations, apply toothpaste to the tongue of the mechanism along its vertical edge. When the door leaf is closed and the handle is released, the locking element is connected to the frame part. The remaining toothpaste mark will tell you where to make the hole for the tongue.

Using the above method is the optimal solution for determining the correct location of the plumb plate. Despite the primitiveness of the method, even specialists resort to it.

The resulting imprint from the protruding tongue of the door latch must be drawn with a stable outline using a pencil. Next, you should use a drill and a chisel, with which you will make a hole for the locking pawl to fit in, and then a metal plate with an opening. You will also first need to make openings for fasteners to fix the plate on the frame of the door.

After creating all the necessary holes, it is enough to attach the plate to the corresponding area. To fit tightly into the box, the metal element must be firmly screwed to the wooden surface.

Finally

So we looked at how to install a handle on an interior door. This material provides an example of how to embed a simple mechanism into a wooden plane. Now you have enough knowledge to cope with the task yourself, without resorting to outside help.

After the door has been installed, you need to install the door handle. Despite the simplicity of the product, it is not so easy to install. In order not to damage the product and the door, it is necessary to follow the rules and sequence of assembly, because each type is assembled and installed in its own way.

Types of handles

Handles can be divided into 2 types:

  • stationary;
  • working together with a lock or latch.

Stationary ones are the simplest. They do not have complex mechanisms; the handle is stationary and moves or scrolls only when the threads become loose or something breaks. Installing such a handle on an interior door with your own hands is quite simple. Most of them are attached with self-tapping screws. For a more aesthetic appearance, make a hidden hole for the screw caps and insert decorative buttons to hide the heads. The through type of connection requires a threaded rod. You just need to drill a through hole at a height of 80-90 cm, screw a pin into one handle, insert it into the hole and screw on the other half of the handle.

Installing a latch handle on interior doors is more difficult, the more complex the design of the locking mechanism. They can be divided into 2 types:

  • rotary;
  • push.

The first type includes ball-shaped handles with the simplest latch. They are also called knobs.

The material and coating of the handles can be any: plastic, metal, wood, glass. The most common are metal ones with sputtering, chrome plating, nickel plating, etc. Strength and durability will depend on the material. Everyone can choose fittings that suit their needs and desires.

In order to understand how to install a door handle, there is no need to go into detail - just consider the installation process.

Installation procedure

The example used is the installation of door handles with a latch. Round and oblong ones are installed the same way.

For installation we will need:

  • hand drill or screwdriver;
  • wood crown with a diameter of 50 mm;
  • wood drill with a diameter of 22-25 mm;
  • chisel;
  • hammer;
  • pencil.

The standard height for the handle is 80-90 cm from the floor. It is usually installed at waist level. It is necessary to take into account that for all doors you need to choose the same height, otherwise it will look ugly.

The height must be marked on the door leaf at the end and side. Mark the center at the end so that you can later drill a hole for the halyard latch. To correctly mark the drill location on the side of the door, measure the distance from the edge of the latch to the middle of the hole into which the square is inserted. Transfer this length to the side of the door.

After marking the centers, we proceed to drilling the holes. To do this you will need a drill, a thin drill (2-4 mm) and feather drills (22 and 25 mm). We need a thin drill to set the guide. When drilling with a feather drill through the exit side, chips are formed. To avoid this, just make a hole with a feather half the thickness of the door, and then start drilling from the back side. To do this, we need to make a guide with a thin drill. The first hole is drilled on the side with a diameter of 25 mm, the second is made on the side with a diameter of 22 mm.

For those models that come with 3 additional screws for attaching the base to the door leaf, you do not need to drill a large hole with a crown. It is enough to make a hole for a “square” with a pen drill with a diameter of approximately 12 mm and holes for the tightening bolts. This design will last longer.

Now mark and make a recess for the latch. To do this, insert the latch into the end and trace the outline of the bar. Then you need to select a groove for the strip. It is better to do this with a milling machine. If you don’t have one, you can get by with a chisel. It is enough to go deeper into the thickness of the plank.

Now installing a handle on an interior door will not be very difficult. All that remains is to assemble the door handle inside the door leaf. To do this, clean the hole from dust and wood chips, insert the latch and secure it with self-tapping screws. However, you should not be zealous and clamp it too tightly, otherwise it may jam.

Now insert the square into the latch hole. Then put on the handle. The kit comes with left and right handles, so make sure you insert them correctly before screwing them on. After installing the handle with the lock, screw the handle with three self-tapping screws to the door leaf.

Mount the second handle in the same way. After assembly, check whether everything works correctly, whether the latch moves, whether it slides in all the way and whether it is jammed. When finished, decorative caps are screwed on to hide the fasteners. On the bottom of the handle, as a rule, there is a hidden screw for a hex key to secure the caps.

If you have a round handle, insert a rod into the hole. It has grooves on both sides. There are also grooves on the handle that must coincide with each other. Put it on and press until it clicks.

Foley handles can be mounted on both left and right doors. To change, you need to remove the cylinder mechanism and the locking mechanism from the handle body and swap them in accordance with the side of the door opening.

Strike plate and lock recess

The installation of the door handle on the interior door is complete. All that remains is to do the final touch, namely, to embed the mating part of the latch into the hole. The first step is to mark the center of the latch. To do this, close the doors not too tightly and draw a pencil at the required level. You can also close the door tightly and open and close the latch several times to leave marks. Now select a groove in the middle of the hole. There is no need to make it deep. Measure the length of the latch at its largest point and choose 1-2 mm less.

The groove under the lock is selected deeper and larger. Everything depends directly on the castle itself. Sometimes the kit may include a plastic pad in the groove - it needs to be inserted before the strip is secured.

A decorative strip is attached over the groove. There is no need to cut it flush. It is enough to screw it with self-tapping screws or nail it with nails. All that remains is to check if everything is working correctly. At this point, the installation of handles on interior doors is completely completed.

Handles with a lock are installed according to the same principle. The difference will only be in the diameter of the end hole.

Installation on sliding doors

When installing handles for sliding doors, you need to have a drill, feather drills, simple drills and a milling machine with a cylinder cutter. The handle is an oblong tab that goes deep into the door. As in the previous case, you need to decide on the height of the location. Then trace the plastic liner onto the door leaf with a pencil.

Using a drill with a 25mm spade bit, drill holes 13mm deep very close together inside the outline. Then select everything with a chisel or chisel. If you have a milling machine, do this with a cutter. This will make the hole neater. Now insert the plastic liner into the hole and secure it with self-tapping screws. Place the pad on it and press until it clicks.

If you have a round handle for sliding doors, then your task becomes much easier. You just need to make a hole using a drill of the required diameter. Then everything is the same as with the oblong handle. Sliding doors can also be fitted with a lock or end catch.

Despite its apparent simplicity, installing a handle on an interior door can be difficult. And if you are not sure about anything, it is better to contact specialists or someone who has experience in such matters. After all, a mistake can ruin your door or handle.

This article will help you figure out how to embed a latch handle into a door leaf. By adhering to the work algorithm described in the article, you can easily perform this operation yourself, with a minimum set of tools and very quickly.

No door can do without a handle. The most popular type of handle for interior doors today is the latch handle.

The design of handles of this type is such that, regardless of appearance, they are all installed in the door leaf in the same way. This article will tell you how to do it yourself.

Latch handle design

The handle itself, that is, the visible part of it, can look completely different. So:

or like this:

All these latch handles essentially consist of two parts - the handle itself:

and the latch mechanism:

Both parts of the latch handle require separate insertion into the door leaf.

Latch handles come without a latch - a door with such handles cannot be locked from the inside, with a latch - an additional rotating mechanism installed on the handle and allowing you to lock the door from the inside, and a key - on one side of the handle there is a key holder that allows you to lock the door from the outside, on the other there is a latch . All handles have design differences that do not in any way affect the insertion process. The internal part (latch) is also the same, that is, it cuts in the same way for all types of latch handles.

So let's get started.

Necessary tool

To make the process of installing the latch handle as easy as possible, you will need:

  1. Hand drill or screwdriver.
  2. Wood crown with a diameter of 50 mm.
  3. Wood drill with a diameter of 23-24 mm.
  4. Chisel.
  5. Hammer.
  6. Pencil.

The crown and drill can be purchased separately, or in the form of a set, which is called “Kit for inserting latch handles.”

Installing the latch handle

1. We begin the installation process by marking the door leaf for drilling. The marking diagram, as a rule, comes complete with the handle.

If there is no diagram, you can mark it manually. To do this, place a mark at a distance of 60 mm from the edge of the door.

2. On the side edge of the door, along the center marking line, mark the center for drilling.

3. Using a chisel, hollow out a three-millimeter recess under the face plate of the latch. It makes sense to first mark the center with an awl so that you don’t have to mark it again.

4. Using a crown with a diameter of 50 mm, drill a through hole. It is better to do this on both sides of the door to avoid damage to the door covering at the exit of the crown when drilling.

5. As a result, we get the following hole:

6. Move on to the side edge. Using a wood drill with a diameter of 23-24 mm, drill a hole for the latch into the marked center. You shouldn’t make it too deep, otherwise you risk drilling through the door all the way to the panel.

7. We now have two holes.

8. Install a latch in the side hole and screw it with self-tapping screws.

9. Remove the upper part of the handle. To do this, look for a hole on the side.

Using the included key or any other thin flat object:

press the tongue inside the hole:

and remove the handle itself:

10. Remove the decorative trim and thereby open the mounting holes.

11. Insert the outer half of the handle.

12. Insert the inner half. We tighten both with the screws included in the kit.

13. We put on the decorative trim and the handle body. Don't forget to press the inner tongue with the key.

14. With the door closed, mark the place where the door jamb latch tongue touches, and then hollow out a recess for the latch tongue in the resulting location.

15. Insert a decorative plastic pocket.

16. Screw on the metal plate.

17. The handle is installed.

If you don’t have a drill, then all the holes can be made using a suitable chisel, however, in this case, installing the handle will require more serious repair and construction skills and may turn out to be an overwhelming task for an untrained person.

Apartment renovations quite often involve the installation of windows and doors. But modern fashion trends have recently forced us to sometimes completely abandon doors, for example, in the kitchen. If the purchase has happened and you have installed an interior door, then next you need to install door handles. In this material we will analyze the steps to install a door handle with your own hands.

What kind of door handles are there?

Stationary, motionless;

Push-type, with lock;

Rotary, often the lock is built into such handles inside.

When entering a building materials store, you need to choose door handles according to certain criteria:

1. Appearance and unlocking element of the handle. Typically, the handle is characterized by an oblong shape, if the handle is equipped with a pressing mechanism, or a ball-shaped handle with a turning mechanism.

2. What is the handle made of and how does it feel to the touch. The door handle can be created from both wood and metal materials. As a rule, this is aluminum, brass, and several other alloys. Also, handles can be made of stone, plastic, or glass. The most common, of course, is a metal handle with a wide choice of coatings, for example - chrome-plated, nickel-plated and others. The coating affects not only the kinesthetic personal sensations of a person, but also the color and durability.

What kind of door handles are there?

Wooden door handles

3. Does the handle have a lock? The handle can either have a lock or be without it. Locks can be built into the handle; usually, you will remember such a handle as the round type. On one side, such a lock is opened with a key, on the other it has a latch.

Attention! In hardware stores, there are handles for the left hand and for the right. Before purchasing, it is important to tell the seller what kind of pen you need.

Door handle diagram (video)

To install a door handle, you will need certain tools:

  1. screwdriver;
  2. hammer;
  3. chisel;
  4. bit;
  5. drill with drills, must be a feather drill;
  6. tape measure, triangle, pencil.

We will analyze the installation using Apecs handles. They are very popular and most common on the Russian market. These handles are made of brass; this material is also the most common in handles today. It is easy to handle, not expensive, and how pleasant it is to the touch has already been appreciated by many owners of such pens.

Apecs Door Handle

Below is a step-by-step recommendation for installing door handles that have a latch but no locking mechanism. It must be taken into account that the insertion of a round type door handle does not have any serious differences from the installation that we give as an example.

Apecs Door Handle

The principle of the mechanical operation of a door handle is simple: the handle turns, the lock tongue goes into the door. For this reason, the very first step will be to create holes for the handle, as well as cut out a groove for the tongue and the rotary mechanism. First you need to decide on the height at which the handle will be located. Professionals advise making a mark at waist level, taking into account how much your arm will bend when turning. As a rule, this is a meter from the floor.

Attention! According to the technical conditions regulated by GOST 6629-88, the height of the door handle must be exactly and exclusively 1 meter from the floor level. But if your house is your own, choose any height convenient for you.

Installation height of door handles and hinges

It must be taken into account that when installing handles in rooms where bedrooms are located, the handles must be installed at the same height. Otherwise, it’s easy for residents to get confused in the dark.

But there are also cases when the door already has connectors for handles, but they are located only at certain points. In this case, if you decide to place the handle in a place other than that provided by the manufacturer, then bad consequences are possible. Including, if children will live in the house for any long time, the height of the handle must also be lowered to at least 75 cm from the floor.

As soon as you have resolved the issue with the height, you must immediately draw a line horizontally at the measured height. A simple ruler will help you with this. Mark the center of the hole 6cm from the door edge with a dot or a circle. Mirror the markings to the other side.

The next step will be marking the lock tongue. To do this, mark the center at the end of the door between the future door handles. You should attach the striker plate and then carefully circle it. Before installing all the elements, you need to erase the pencil as much as possible, because after installation it will be difficult to do this. Leave only the elements you understand for reference.

Having made markings on the door, you need to start drilling holes for fastening the door handles. Making them yourself is not difficult. Using a drill or a pen drill, make suitable holes to connect the door handles with a square.

At the end of the door, similarly, using a drill and a feather drill, make a hole, the depth of which will be equal to the length of the latch mechanism. Then, using a chisel, having measured the thickness of the lining in advance, remove the excess elements to a distance that will allow the strip to fit completely into the door leaf. This whole process is clearly demonstrated in the video.

Once you have installed the latch, you need to install the door handles you purchased. Initially, the square from the kit is inserted. It will move the tab when you turn the handle.

Then, remove the trims, which are round, threaded, and decorative. They have a special thread on the inside at the base, which is screwed to the door using screws.

DIY door handle installation

Now you need to properly secure the locking screw of both handles; a special hex wrench will help you with this, usually included in the kit. The locking screw itself is needed to firmly press the door handle to the turning square, while at the same time preventing any slipping during operation.

DIY door handle installation

Preparing the door frame

The last step is to position the door handle correctly. Those. make installation of the mating part of the latch. To do this, you need to lubricate the lock tongue with oil, close the door, and make a mark on the door frame with your tongue, in simple terms, scratch it. At the same time, make several test openings and closings with the handle. Then, you need to attach the trim, which should rotate directly to the jamb, and trace it along the contour, including the inner hole.

Using a drill, you need to drill a hole for the lock tongue of the latch, and the rest of the part needs to be deepened using a chisel or chisel. Make the depth 2 millimeters, or 1, depending on the depth of the bar itself. All that remains is to fasten our plank with two screws. Use an awl to make marks for the screws, and use a drill to drill holes of the required diameter accordingly. Using a screwdriver or by hand, secure the strip in the door jamb.

Cut the corresponding holes in the door for the door handle

Can you imagine ordinary doors without a handle? It would seem like such a simple design, but in fact it is a very important attribute. Installing a door handle on an interior door is a task that consumers face when purchasing and installing a new leaf. It is quite possible to solve the problem on your own. It is only important not to make a mistake with the choice of design.

Types of Door Handles

There are various types of handles that are different from each other in color, shape, material, mechanism and installation method. If we take the last feature as the basis for the classification, then there are two types of pens:

  1. Invoices.
  2. Mortise.

Installation of first-class products is simple and does not cause serious trouble. They are simply fixed to the surface of the canvas, unlike other types of products. Installation of mortise handles involves pre-drilling a hole in the door leaf.

Mortise devices are divided, in turn, into two more types:

When purchasing accessories, pay special attention to the raw materials it is made from. Products can be made of metal, wood, glass or natural stone. They should be selected according to the color and model of the canvas, as well as the style of the interior.


Hidden handles can be installed for sliding systems

It is worth noting that the handles are of a hidden type. They are designed for sliding systems such as sliding doors. When the sashes move, the products do not interfere or damage wallpaper or walls.

Installation height

At what height to mount the handle is not clearly stated anywhere. Behind the scenes, it is installed in products made from MDF and timber at a distance of one meter from the floor covering. It can be lowered or raised a little - it all depends on the taste of the owner of the living space.


The installation height of the door handle is approximately 1 m

The installation height of the product is affected by the height of the residents. As practice shows, a handle at a distance of 1 m is the best option for adults and children. When installing, also take into account the level of the handles on other doors. Products must be at the same height.

Required Tools

To install the handle, arm yourself with tools, without which it will not be easy to do this:

  • a simple pencil;
  • square;
  • roulette;
  • chisel;
  • screwdriver;
  • drill;
  • drill;
  • crown.

The crown and screwdriver can be replaced with other available tools, but the quality of the work will suffer and it will take a lot of time.

Before starting installation, read the instructions for the product. It indicates all the dimensions, which will help you choose the right drill bit and crown according to the radius.

Step-by-step installation instructions

If you have not encountered a similar question before, do not be afraid. Even those who are not involved in construction can handle the installation of the handle. You just need to follow the detailed diagram step by step.

Marking the canvas

Installation of the handle begins with markings on the doors

Marking is where the whole process begins. Having calculated at what height the handle will be located, place marks on the door in the places where the holes will be made.

Use a simple pencil, a tape measure and a corner and draw a horizontal line on the flat surface of the canvas. Then transfer it to the end and opposite side of the sash.

Place a mark on the end of the product in the center of the drawn line. It points to the place intended for the recess under the tongue. From the edge of the door at a distance of 0.6 cm, draw a point on both surfaces of the door. This place is intended for the handle.

Drilling holes for handle and lock

It doesn’t matter at all in what order you make the holes: first for the handle, and then for the lock, or vice versa. Just remember that things don’t like to be rushed.

For the handle, the opening is drilled with a drill and a crown. To make it smooth and neat, you need to drill from the inside and outside of the door to a depth equal to ½ the thickness of the leaf.

For greater accuracy, craftsmen advise marking this depth on the crown with a felt-tip pen. By adhering to this rule, you will definitely not damage the product. To ensure a straight hole, keep the drill straight and do not allow it to deviate to either side.


When drilling a hole for the handle, the drill must be held level

To install a latch into an interior door with your own hands, arm yourself with a drill and a pen. In this case, you need to be extremely careful, since the gap between the pen drill and the end angle is small.

Lock installation

The mechanism must be inserted into the hole drilled under it. Press the overlay to the end of the product and outline it with a pencil on all sides.


Then use a chisel to clear the top layer from the canvas and make a recess the size of the thickness of the overlay. This is done in order to press it into the doors.


The cover is fixed with screws. Recesses for them are made even before the fastening is carried out.


The lining is fixed with self-tapping screws

Handle insert

Products with screws located outward do not require disassembly. When installing one component of the structure in place, you must try to get into the latch hole with 2 guides equipped with threads for bolts.


Door handle installation diagram

After this, the second component of the device is inserted and tightened with bolts. Screwing must be done evenly in order for the handle to function properly.

Products with hidden screws must be disassembled. There will be instructions and a special key to help you. The handle can be removed without problems by pressing the stopper with a key. The handle is installed in place after the collapsible part is bolted.

Marking the loot

After installing the handle, make a recess in the tray for the tongue. To do this, you need to take the measurements correctly. Precisely executed markings guarantee good operation of the lock and the door itself.

To make marks, cover the canvas and mark the distance from the top to the bottom of the tongue on the loot. Use a square to find the middle of the castle and put a “cross” in the loot. At the marking site, we will drill a recess with tools and get rid of excess material with a chisel.

Cutting a groove in the loot

Before screwing the cover, watch how the canvas closes. If there is no friction or other problems, this means that the groove for the tongue was made correctly.

Close the door and try to tug it slightly. If it wobbles, then this indicates the presence of a slight backlash. Don't be alarmed, this is normal. When a counter plate is added to the groove, everything will fall into place.

The answer is attached flush with the loot. Just like when installing a lock, it should be sunk into the hole.


The strike plate is attached flush with the loot

Sometimes, after installing the trim, the play does not disappear and the doors continue to wobble. This defect can be corrected by using a screwdriver to bend the tab with a small hole on the answer.

Caring for door hardware

In order for a thing to last for many years, it needs to be looked after. It's the same with fittings. Over the years, it ages and wears out, which negatively affects the product as a whole. To slow down this process, do not forget to take care of the fittings.

To care for your hands you need:

  • Wipe them from dust with water and special cleaning products. Avoid products that contain acids, alkalis or abrasive particles. They can damage the outer coating of the product, leading to rust. After washing, the product should be wiped with a dry cloth.
  • Tighten the loose handle. If this is not done, the mechanism will break.
  • Protect the product from rough mechanical influences.

In addition to the handle, the door lock also needs your attention. Basic care in this case means regular lubrication of the mechanism with special means.. Sometimes sunflower or other vegetable oil is used as a replacement.

Considering that many parts of the mechanism are not easy to reach, a special nozzle in the form of a thin tube is used for lubrication. Often, for these purposes, the cover is removed or the handle is dismantled.

To lubricate hard-to-reach areas of the handle, use a tube attachment

Thus, having studied the basic intricacies of installing the handle, you are able to master this task without outside help. The main thing is to believe in yourself, and then the reward in the form of a well-installed pen will not be long in coming.