Dowel nail - existing types and scope of application. Types of dowels and their application Dowel types and description

In this article we will talk about the varieties and types of popular fasteners - dowels. The main types of dowels and their use in construction and repair.

A wooden plug in a brick wall or concrete for tightening a screw looks primitive and outdated. In construction, modern special products have been used for quite a long time - dowels, used for making blind fastenings. The latter differ from through ones, which involve drilling a hole through the wall and using various connecting elements, for example, a threaded rod on both sides, to which nuts are screwed, anchor washers are welded, etc.

The range of dowels today is simply huge, which are used for various purposes. The most popular and sought-after types of dowels will be discussed below.

Dowels are produced for solid (solid), layered, multi-hollow and hollow-core walls, and are used in cases where one free end of an anchor or screw is not accessible for a tool. For massive walls without voids, the dowels operate according to the expanding principle, and for hollow walls - according to the anchoring principle.

Expanding dowels are available in two versions - this is a deformable coupling made of nylon or metal, in which the cartridge opens during the passage of the rod. Anchor dowels are quite a tricky device in technical terms. They can be executed in several versions. For example, for some, when the rod of the fastening element is twisted, the nylon cartridge expands at the end, turning into a so-called “bulb”; for others, the end of the cartridge, due to the presence of special transverse notches, turns into a kind of locking figure in the form of a diamond; while for others, the tip of the cartridge is screwed on onto the rod thread in the form of a knot, thereby turning into a thrust nut on the side of the wall void.

There are anchor dowels on sale that resemble a whole mechanism. Their tail part, under the influence of a spring, gradually begins to open or rotate around the hinge. There are types in which the shank is mounted in a locking position using the so-called “stalk”, with its end remaining outside after installing the dowel.

The latest in fashion is a universal nylon dowel, designed for attaching metal slats and wooden blocks to wall surfaces and floors, acting as partition frames, suspended ceilings, window and door frames, lathing for mounting facing slabs, etc. This dowel acts as a spacer in places of contact with dense sections of the wall in layered and multi-hollow walls, and as an anchor - in places of contact of a dense part with hollow ones due to open parts in the form of a ring in the coupling body. Resting against the socket against its side walls, the open rings with their ends create additional friction during the rotation of the rod.

The end of the fastening rod on the outside is made in the form of a screw or nail head, a threaded cylinder, a screw head, in the form of a ring, a hook, etc.

Dowels differ from each other not only in the material used for manufacturing and the method of installation in the structure, but also in the degree of shear and tensile load on the fastening rod. Simply put, some products are designed for fastening ordinary household items of small mass, while others are designed to withstand various building structures in large structures and buildings.

There are special steel dowels, whose task is to connect concrete foundation shoes with the supports of metal columns for massive overhead cranes, characterized by a lifting capacity of several tens of tons. It is interesting that if you do not use dowels, but put anchors into the concrete shoe along with mounting plates and weld the supports of steel columns to them, then the metal costs for such embedded elements in this case are compared with the volume of metal for the main concrete reinforcement.

In the case of using dowels, according to precise markings, holes are drilled on top of the concrete foundation shoe using a hammer drill, into which solid metal bolted dowels are then installed. When using this method, the total weight of all dowels will not exceed a fraction of a percent of the volume of metal using the usual installation method.

Application of dowels

Regarding apartment renovations, especially in new buildings where there are reinforced concrete walls and ceilings, the dowel is simply an irreplaceable element, since all operations for fastening objects to ceilings, walls and floors are performed only with the help of dowels.

The choice of dowel for a particular case depends on several factors. The most important thing is to clearly determine the expected load for a particular item and choose the right dowel thickness, its type and the appropriate screw.

If the hole will be located horizontally, for example, to hang a kitchen cabinet or bookshelf, dowels with an outer diameter of 8-10 millimeters are usually used. They are buried in a solid section of a brick or concrete wall by about 30-50 millimeters. When you need to hang a more “important” object, for example, a wall bars or some kind of exercise equipment, you should use dowels with a recess of 80-100 millimeters into the wall.

When the hole is located vertically, that is, when the load will be directed downward when installing, for example, a suspended ceiling or a heavy chandelier, dowels with spacer wings and transverse notches should be used. It is very important that the drilled hole exactly matches the outer diameter of the dowel. At the same time, it must go in with a certain force (ideally it is driven in with a hammer), and its length must be at least 40-50 millimeters.

Often, for the sake of greater reliability, the hole together with the dowel is treated with good glue, and after installing the dowel, before tightening the screw, leave it for at least a day until it completely sets. But if the dowel was selected correctly and the load was calculated correctly, then this operation is completely unnecessary.

It is not possible to renovate a house or screw cabinets to the wall without a special fastener, which every man probably has in his toolbox.
For those who live in a wooden house, it is enough to use only nails and a hammer to get a reliable fastening. Thanks to its structure, wood reliably holds a nail and easily allows it to penetrate under hammer blows. This property of wood was used by builders for many years, installing wooden plugs in brick and concrete walls, and then screwing screws into them.

Now this archaism has been replaced by dowels. A dowel is usually called a special factory product for mounting a blind fastening.

What kind of dowels are there?

Polypropylene expansion dowel. It is made of nylon or polypropylene. The expansion dowel is used together with self-tapping screws for fastening into concrete, stone and brick.

Drywall dowel. The drywall dowel is made of metal or plastic. It is used for fastening structures and elements in gypsum fiber and plasterboard sheets or in porous concrete. Requires the use of universal screws and self-tapping screws. Metal dowels of this type can be mounted without first making holes for them. This is achieved due to the fact that their tip is made in the form of a feather drill.

Dowel nail. The dowel-nail is made of polypropylene and nylon, and the nail is made of steel. It is used for quick fastening of metal profiles, slats, windows, guides, baseboards, sheathing, timber, plywood to brick or concrete, cable ducts.

Nylon dowel made from polypropylene and nylon. It is used for fastening together with self-tapping screws dia. 2-16mm into any wall surface. The dowel is held in this hole using specially directed antennae.

Frame dowel made of metal. It is used for fastening door and window frames, as well as for cladding elements through a layer of thermal insulation and plaster. There are two subtypes of this dowel: the first is suitable for working with soft materials, the second - with solid hard materials.

Nylon universal dowel made of polypropylene and nylon. It is used to fasten door and window frames, metal slats, suspended ceilings, sheathing for cladding slabs, and wooden blocks to a surface with a hollow or empty space inside.

Butterfly dowel made of metal. It is designed for fastening into hollow structures that will withstand heavy loads.

Dowel for thermal insulation. This dowel is made of plastic or a plastic base and a metal nail. Designed for attaching polystyrene or mineral fiber insulation to concrete or brick walls. Requires pre-prepared holes in the wall.

How to choose a dowel?

The dowel should be selected depending on its future location and load:

1. For horizontal fastening into a brick or concrete wall, it is worth selecting dowels with a mounting depth of 30-50 mm and an outer diameter of 6-10 mm.
2. To fasten wall bars and exercise equipment, as well as other heavy outdoor objects, choose dowels with a mounting depth of at least 80 mm.
3. If the load will act downwards on the dowel (chandeliers, suspended ceilings...), then pay attention to dowels with transverse notches and spacer whiskers.
4. When selecting a dowel for an existing hole, strictly ensure that the diameters match; the dowel should not be smaller than the diameter of the hole in which it will be mounted.

Using dowels for repair work, you can prevent the destruction of weak walls in the place where the fasteners support due to the fact that, with its diameter and material, the dowel will act as a softening gasket, and on hard surfaces the dowel will fit tightly to the fastener and help distribute the load evenly.

Steel dowels for hollow materials MOLLY
Steel dowels for hollow materials and plasterboard walls.
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Metal dowel nail HD
Metal quick-installation dowel-nail for fastening in dense materials. The material of the dowel is ZnAl, the nail is galvanized steel.
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Universal metal dowel MUD
Galvanized steel (yellow) expansion dowel for various building materials. It can be installed in low-density aerated concrete without drilling a hole.
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Mounting for thermal insulation IZ
Polypropylene expansion dowel for fastening mineral wool and foam boards.
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Dowel nails for quick installation SM
Polyethylene expansion dowel for quick installation.
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Folding spring dowel SPDK
Folding spring dowel for mounting in suspended ceilings.
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Expansion dowels TNF/W
Polypropylene expansion dowel.
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Expansion dowel for mounting in plasterboard TT 22
Polypropylene expansion dowel complete with attachment for fastening in plasterboard walls.
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Self-tapping dowel for mounting in drywall DRIVA SPA
Self-tapping dowel made of ZnAI alloy for fastening in plasterboard walls.
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Expansion dowels for standard KRH fastenings
Polyethylene expansion dowel.
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Facade and frame expansion plugs TSX-S
Polyamide (nylon) expansion dowel for hollow (hollow) materials. Galvanized steel screw with hex head.
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Expansion dowels for standard TCHAPPAI fastenings
Polyethylene four-spaced dowel with a collar, spikes and whiskers for fixation during installation in dense materials.
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About dowels

Dowel- a fastening element designed for fastening various building structures, insulation, cladding materials to the surface of walls of various types. Dowels are used when the free end of the rod (screw, anchor) is inaccessible to the installation tool. The dowel is driven into the wall or main part, a screw is screwed into it, and the dowel expands and cannot be removed. Today, the dowel is a universal and popular fastener.

Dowels come in different designs and are made from different materials.

All dowels can be divided into two groups:

1. Dowels for monolithic (without voids) bases - have a spacer operating principle.

2. Dowels for hollow bases - have an anchor principle of operation.

Dowel classification:

Standard Nylon Dowels: The anchors are suitable for any wall and can be used with screws ranging from 2mm to 16mm in diameter.

A hole is drilled in the wall corresponding to the diameter of the dowel, in which it is held with tendrils directed back, and when wedged with a screw, it is “tightly” pressed into the walls of the hole with its large teeth.

Dowels for aerated concrete: A hole is drilled under such a dowel corresponding to the diameter of its core. It is driven into the hole with hammer blows, and at the base it is held in place by spiral ribs and wedging under the action of a screw.

Frame dowels: length from 60 to 360 mm. There are two main types - for solid solid bases and for soft and hollow (slotted) materials. The elongated spacer part ensures that the dowel engages several jumpers in the base with voids at once. They are used for fastening window and door frames, as well as cladding elements through a layer of plaster and thermal insulation.

Distance dowels (adjusting): secure the sheathing slats under the sheathing at some distance from the wall. They allow you to adjust the position of the sheathing slats relative to the base in the range from 0 to 30 mm during their installation due to the dowel and screw of a special design that are divided into two parts (one for the base, the other for the slats).

Universal: when attaching objects to a hollow base, they “determine” the presence of a hollow space. In the cavity, the dowel bulges and is thus fixed in it. When attached to a solid base of brick or concrete, it expands and comes into close contact with the walls of the hole. Dowels with spring-loaded folding strips: designed for attaching objects to hollow partitions and false ceilings, for example, for hanging chandeliers. The dowel strips, having passed through the hole into the cavity behind the casing, open under the action of a spring and rest against the inner surface of the casing.

Metal: for hollow thin-walled structures they can withstand quite heavy loads.

When the screw is screwed in, the dowel plates bulge in all directions and are pressed against the inner supporting surface.

Nail dowels: designed for quick fastening of baseboards and sheathing slats under sheathing when you need to install a large number of them. They are equipped with a nail that has a “jarch” (knurling in the form of reverse cones). The dowel with a nail is inserted into the hole in the wall through the fixed strip. The nail is driven in with a hammer.

Insulation holders: for attaching mineral wool or rigid foam insulation. It is driven into a hole in a concrete or brick wall without a nail or screw.

Dowels for concrete and solid bricks: designed for large (up to several tons) loads, made of metal and equipped with threaded rods or bolts. Suitable for attaching sun awnings, garage doors or lifting hoists. Plastic and metal: for soft materials (plasterboard and porous concrete).

What is a dowel

Allows installation without pre-drilling a hole. Thanks to the tip in the form of a feather drill and large, screw-like threads on the outer surface of the body, the dowel can be easily screwed into the wall with a regular screwdriver.

Injection dowels: a mesh anchor is inserted into the hole. Using a special syringe, a quick-hardening mixture is injected into the dowel through a protective sleeve. When the mixture is pumped, the mesh expands, forming a kind of dowel in the shape of a ball. To fasten objects to walls made of slotted bricks or blocks, instead of a mesh dowel, you can use an injection dowel without mesh.

Home / Educational program / Review of the main types of dowels

Overview of the main types of dowels

A variety of dowels are used today in construction and operation, each of which has its own distinctive properties and scope of application. To learn more about them, you should carefully study the features and modifications, as well as see an overview of the most popular and popular products.

If you want to learn how to use a dowel correctly, watch the video.

dowel nail

It is a fastening element consisting of 2 parts - a plastic spacer shell and a metal screw. Most often used for fastening objects to solid products and materials - stones, bricks, concrete structures. To check the quality, you should carefully inspect the dowel nail for cracks and symmetry, paying special attention to the strength of the plastic shell.

Prices

The minimum price of the product is 174 rubles. for 1 package (100 pcs.), and the maximum is 856 rubles. for 1 package (100 pcs.).

Dowel screw

This fastening material is a product used for reliable fastening of structures and objects in solid and solid concrete and wooden structures - bricks, reinforced concrete, natural stone. The main parameter of its quality is a durable plastic shell made of nylon material, as well as reliable galvanized steel. When purchasing, it is advisable to see the quality certificate for the product.

Prices

In Russia, the price range for dowel screws ranges from 42 rubles. for 100 pcs. up to 460 rub. for 100 pcs. depending on the diameter and length of the product.

Expansion dowel

This product is a fastening system that includes a polypropylene ribbed element and a metal (or plastic) screw with a wide pitch. An expansion dowel is used to securely connect self-tapping screws to a load-bearing base - concrete, stone or wood. This fastener is also used for attaching drywall, plywood or aerated concrete. To check the quality of the fastener, it is tested for bending, which should be minimal.

Prices

In our country you can buy an expansion dowel from 22 rubles. for 100 pcs. up to 100 rub. for 100 pcs.

Dowel clamp

This interesting and very important fastening element is used to securely connect wires to a load-bearing surface - a wall, ceiling or rail. The dowel clamp is a reliable PVC product, which is made in the form of a loop with growths at the end. Having strengthened the bundle of wires, the dowel is driven into the pre-drilled hole with light movements, securely fixing into it.

Prices

The minimum price of the product is 101 rubles. (for 100 pcs), and the maximum is 148 rubles. (per 100 pcs).

Self-tapping dowel

This fastening mechanism consists of a plastic shell and a steel insert in the form of a screw, which is screwed in and pushes the plastic shell inside the product.

Most often it is performed with a flange, which prevents the screw from being buried inside the wall. Used for fastening in brick and block structures, monolithic reinforced concrete walls, wooden products. To check the quality, you should carefully inspect the product visually - there should be no cracks on it, steel self-tapping screws should be without nicks.

Prices

In our country, the minimum cost of dowel screws is 120 rubles. (for 200 pcs.), but the cost can also reach 360 rubles. (for 200 pcs.).

Plastic dowel

It is a PVC or nylon shell that has a hole in the inside and exciting ribbed edges and hooks on the sides. Used as a reliable fastener for connecting structures and attaching additional elements to stone, concrete or brick walls. To check the good quality of plastic dowels, it is best to test them in practice - they should not bend or crack during operation.

Prices

You can buy a plastic dowel for a price starting from 30 rubles. (for 100 pcs.) up to 200 rub. (for 100 pcs.).

Dowel for thermal insulation

This product is widely used for fastening thermal insulation boards - polystyrene foam, polystyrene foam, mineral wool panels.

Dowels: varieties, types, application

The thermal insulation dowel is a plastic product with a very wide cap on one side, thanks to which the thermal insulation material is securely attached to the load-bearing surface of the wall. To check the quality of products, you must have a certificate that certifies the technical compliance of the product.

Prices

Today, a dowel for thermal insulation can be purchased at a price of 26 rubles. (for 10 pcs.) up to 240 rub. (for 10 pcs.).

Video

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Which dowels are better

Which dowel to choose is a rather trivial question, which actually has a clear answer: you need to choose the dowel that matches the installation material and type of installation. How many times will a master curse a scrolling self-tapping screw when installing a cornice on a foam concrete partition of a house of the 1-LG-600 series? How many people have wrapped an unfortunate dowel with electrical tape, put a cable casing on it, put on a heat-shrinkable tube - and all to no avail!

Who would guess to put two or three pieces in a row and turn them all the way through so that they don’t turn? And how many times will a special expansion dowel be used for gas and foam concrete, not to mention the fact that few suspect, and even fewer know for sure, that such a dowel, it turns out, exists in nature! But a unified classification of dowels, reflected in any regulatory documents, does not exist in nature.

So here, in fact, everything is both simple and quite complicated at the same time. Let's try to figure out what kind of dowels there are in principle:

According to the operating principle:

1. Spacers, which are held in a hole of a certain diameter due to expansion when screwing in self-tapping screws - the ribs of the spacer dowel rest against the walls of the hole and wedge in it. They are intended for solid materials (concrete, reinforced concrete, asphalt, even wood and wood-based materials).

2. Anchor ones, which, in addition to wedging in the material, are also capable of deforming so that the back part of such a dowel cannot fit into the hole (anchor principle). Such dowels are intended for hollow and porous materials (masonry made of hollow bricks, aerated concrete, foam concrete, etc.), as well as sheet materials such as gypsum board.

By installation method:

1. Twisting - this long and awkward word speaks for itself and precisely defines the method of installation of this class of dowels. Tightening is done either with a screwdriver of the desired configuration, or with a similarly equipped screwdriver (details below).

2. Driven - similarly, the method of installing such dowels is hammering, usually with a hammer or mallet, but sometimes with the help of other tools: for example, these can be pliers, a wooden block, a fragment of a solid brick or a piece of concrete, a steel angle, etc. .

They also separate through installation, in which part of the dowel is passed through the structure being fixed (has an elongated non-expanding part) and preliminary, in which the dowel is placed in the hole along its entire length (the most common type of installation).

According to the material of manufacture:

1. Plastic - made of polyethylene, polypropylene or polyamide (nylon).

2. Metal - made of aluminum alloys, brass, stainless steel.

By type of front part:

1. With a side (cuff) - when screwed, the side wraps around a screw (screw).

2. Without a side. True, you can get an effect similar to the side if you do not insert the dowel all the way, leaving about 3 mm outside.

By purpose, scope and design features:

1. Standard dowels for solid materials are the most common type of this type of fastener. The classic version is made of nylon (polyamide), and it is most represented on the market by the Finnish company SORMAT (series NAT 5, NAT 6, NAT 8, NAT 10, NAT 12, etc.). In second place is the Swiss manufacturer MUNGO, whose dowels are painted in a characteristic red-orange color and are also made of nylon.

This is a fastener that is suitable in most cases for most materials. However, nylon has one very unpleasant feature - at low temperatures its strength increases sharply, and viscosity decreases. Therefore, when working “at minus” in the open, there are frequent cases of ruptures of nylon dowels (especially when using dowel-nails), as well as cases of inability to screw a self-tapping screw or screw into them completely.

However, practice has shown that it is better to use a brittle nylon dowel than a viscous polyethylene one made at the lowest level of quality. As a last resort, you can use an industrial hair dryer, performing installation in a warm stream of air.

2. The dowel for aerated concrete and foam concrete has the ability to wedge in the hole, held in place by special spiral ribs. A hole for it is drilled according to the diameter of the core, and then the dowel is driven in with a hammer and a screw is screwed into it.

3. Frame dowels are available for both solid materials and soft or hollow ones. They are used when installing window and door frames, as well as for fastening cladding elements through a layer of heat or sound insulation, a plaster layer, etc. Frame dowels can cling to partitions in the material, for which they have an elongated spacer part.

4. The adjusting dowel allows you to secure the structure at a certain (up to 30 mm) distance from the base; consists of two parts, one of which is intended for the base, and the other for the attached structure; also comes with a special screw. Designed for fastening various battens under cladding with sheet and/or panel materials.

5. The universal dowel is convenient for fastening both to cellular, creviced materials such as hollow bricks, and to hollow gypsum plasterboard partitions and suspended ceilings of various types. It is designed as follows: when a screw is screwed in, the dowel material seems to “remember” the presence of a hollow space around itself and, accordingly, is deformed in it. There is also a modification of the universal dowel with spring-loaded folding strips: the strips go inside the hole in the sheet material along with the dowel, and then fold back like spacer springs in spotlights, resting against the inner surface of the sheet.

6. The dowel for gypsum plasterboard and porous concrete (“posidriver”, “jet plug”) is used for static fastening of suspended structures, as well as paintings, etc. on walls and ceilings made of gypsum plasterboard, SML, MCL and similar materials. It is screwed into the base using a screwdriver or a screwdriver, since it has a “posidrive” (PZ) type slot in the front part, and in the “back side,” that is, the back part, there is a point along the profile of the first drill, going towards a cone.

“Pozidrivers” (that’s what we called these dowels, from the bourgeois name “pozidrivers” painted on the boxes with “MUNGO” fasteners in which they were delivered to the site) are made of both plastic and silicon-aluminum alloy (silumin). A plastic dowel (“fiber jet”) is used only for fastening to gypsum plasterboard and similar materials, while a silumin dowel is used for gypsum plasterboard, gypsum, chipboard and cellular concrete. Self-tapping screws for them are included, but they are usually of lousy quality.

Plastic posidrivers can be mounted using the so-called. “drill-screwdriver” (this is an attachment for a screwdriver), since some of their modifications do not have their own drill, unlike silumin ones. True, this attachment is not easy to get.

DOUBLES. VARIETIES AND FEATURES OF USE

The soundproofing dowel is placed in a special rubber shell that absorbs extraneous sounds.

8. Collet dowel - a cylindrical sleeve with an internal thread, usually made of brass (this alloy has the necessary flexibility and at the same time is durable). The inner part (which is threaded) has the shape of a cone, and deep notches are applied to the sleeve on the outer part. There are options made of sheet steel, carbon or stainless steel, including without thread, for example, HILTI HKD-S.

The hole for this type of fastener should be drilled along the diameter of its front part. Next, we clean the hole (unlike, say, the process of installing a nylon dowel, cleaning here is strictly required), install the collet into the hole (we hammer it in with a hammer or, better yet, a rubber mallet so as not to damage the thread). We tighten the screw/bolt - the sleeve expands thanks to the notches, preventing rotation, and it is secured in the hole. A collet dowel is used for fastening various types of suspended structures in solid materials (concrete, reinforced concrete, monolithic brick, wood, etc.)

Finally, disc-shaped dowels, used for fastening heat-insulating boards on the facades of buildings and structures, and the so-called dowel-nails, which are combined types of fasteners, stand somewhat apart (unlike the ordinary dowels discussed here, none of the parts of these types can be fully used in separation from the other).

Self-tapping screws for concrete

A turbo screw for concrete (dowel, frame screw) is a regular self-tapping screw. Its only difference is the thread cut unevenly in height. The tip is sharp. A countersunk head with a slot, often made for an asterisk hexagon (TORX T30) or for a cross bit. Most often used for fastening frame window and door structures (concrete, brick, natural stone).

These self-tapping screws can also be used for fastening lightweight hanging structures: cabinets, hangers, cables.

The head has a countersink on the inside for a tight fit of the fastener to the part.

Concrete hardware is made of high-strength steel and coated with yellow zinc. All items have the same diameter: 7.5 mm. Popular length sizes range from 52 to 202 mm in increments of 25-50 mm. Also, dowels can be made with different types of heads: with an external thread (“stud”), with an internal thread (“barrel”), with a hex head with a TORX slot, with a hex head with a wrench, with loops, and convex heads.

Some manufacturers offer self-tapping screws for concrete without drilling, capable of being screwed into concrete without preliminary preparation of the hole: such hardware is more firmly anchored in the base. High-quality concrete screws can be reused. This is convenient when installing temporary structures: ladders, handrails, scaffolding. For quick installation in one operation, it is convenient to use impact wrenches. They allow you to screw a self-tapping screw into concrete with or without preliminary drilling.

How to twist correctly

Screws for light and heavy concrete are no different. Self-tapping screws are used without dowels. The dowel is fastened after preliminary drilling of the hole. Retention at the base occurs according to the principle of an anchor screw. Afterwards, it is screwed through the part into the prepared hole. With notches for countersinking, the self-tapping screw firmly adheres to the part, due to the friction force, it additionally holds it and dampens vibrations.

It is important to use the self-tapping screw correctly, as you can easily break it off.

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It is necessary to tighten a screw with a non-countersunk head with a certain force, since due to high loads when tightening, it can be broken by simply over-tightening. The risk of head breakage is also associated with the high heating temperature of the self-tapping screw body when screwing into concrete.

The order of twisting the dowel:

1. Fastening of window and frame structures is carried out by at least two people.
2. Align the structure to be strengthened and secure it.
3. Transfer the installation dimensions to the hole drilling plane.
4. Remove the structure and drill holes.
5. Reinstall the structure and screw the screw through the structure into the prepared hole.

Table 1. Standard sizes of pre-drilled concrete screws.

Prices

The price of concrete screws is almost the same everywhere. The product is valuable: a pack of screws for 100 pieces costs from 250 to 550 rubles, the price is affected by the length of the screw. Many suppliers offer to buy self-tapping screws for concrete: the popularity of dowels among window and door workers has not gone away for the last 10 years. Installation organizations (electricians, plumbers) and construction companies also do not disdain this product. Turbo screws for monolithic construction sites are purchased en masse. The main selling sizes are 7.5*112, 7.5*132, 7.5*152.7.5*202.

Due to its popularity, it is produced both in the Russian Federation (according to GOST 9012-59) and imported in large quantities from Europe and China.

When carrying out repair work and landscaping of premises, there is a need to ensure reliable fastening of interior items, electrical equipment, and hanging furniture to various bases. To accomplish this task, a special fastening element is used - a metal dowel, as well as clamps made of plastic or nylon. The fastener ensures reliable fixation to concrete, brick bases, as well as cellular blocks. Let us consider in detail what an expansion dowel with a metal rod is.

Drive-in dowel-nail 3.7x30

What is a driven dowel

A dowel bolt is a special fastening element that provides the ability to fasten wall cabinets, electrical equipment, cable ducts and interior items.

The design of modern fasteners ensures reliable fastening in various building materials:

• heavy grades of concrete;
• blocks made of porous composites;
• plasterboard sheets;
• various types of bricks;
• cinder blocks;
• plaster.

The fastening device, which is also called a fisher dowel, is made in the form of a sleeve, shaped like a cylinder with protrusions:

• the outer surface of the cylinder, in contact with the hole in the building material, is equipped with special hooks. They increase grip;
• There is a hole inside, parallel to which narrow cuts are made. They provide the possibility of deformation when screwing a bolt or screw.

Driven dowel (collet)

The fastening mechanism is installed and operates according to a simple algorithm:

1. A cylindrical element is hammered into the prepared channel.
2. The mounting element is screwed into the bushing hole.
3. The collet mechanism expands when a screw or bolt is screwed in.
4. External corrugations fit tightly into the building material.

Let us dwell in more detail on the design of the device.

Components and design features

Regardless of the material used, the working bushings, all types of dowels consist of the following structural parts:

• a working sleeve, which is driven into a hole pre-drilled in the building material;
• fastening element, in the form of a self-tapping screw, threaded bolt or screw, screwed into the plug.

The body of the sleeve itself includes two sections:

• the upper part, which maintains the diameter when screwing the hardware. The non-expandable section of the plug retains its original shape, directing the fastening element deep into the channel;
• the working part, which is also called the spacer. A screw-on self-tapping screw pushes the sleeve segments apart. They are pressed against the building material, creating a persistent knot.

Metal butterfly dowel for plasterboard

The size of the non-expanding section is determined by the fastening features:

• the reduced length is used if it is necessary to ensure the operation of the collet mechanism over the entire channel area;
• the enlarged non-expandable section allows you to install fasteners through cavities or a layer of thermal insulation.

Structural parts of the spacer mechanism:

• locking elements in the form of spikes, bosses or corrugations. They make it difficult to rotate the sleeve when screwing in a screw or bolt;
• spacer teeth and spikes. They increase the efficiency of contact with the channel walls, preventing the sleeve from falling out;
• slots located parallel to the longitudinal axis. They divide the body into separate segments that alleviate deformation and equalize pressure.

A correctly installed expansion dowel is securely fixed in all building materials. A metal spacer element in the form of a bolt or self-tapping screw, when screwed, increases the diameter of the sleeve and, accordingly, increases the efficiency of contact with the material.

Main advantages

The dowel element has a range of advantages:

Along with increased performance characteristics, dowel fasteners are reliable and durable.

What are the types of dowels - types and classification

Dowel fasteners are now offered in an expanded range. It is not difficult to purchase the required modification to ensure strong attachment to any building material.

The following points influence the choice of a specific model::

• fixation method;
• installation method;
• sleeve material;
• application area;
• base material.

Let us dwell in detail on the main provisions of the classification.

Types of dowels and their use according to the method of fixation

Metal dowel-nail

The design features of the fastener are related to the characteristics of the material into which the sleeve is driven.

All types of dowel clamps according to this criterion are divided as follows:

• products for materials with increased density. Most fasteners with a spacer operating principle are suitable for solid concrete walls, brick foundations and heavy concrete. The products differ in the configuration of the protrusions, the number of cuts and sizes. Reliability of fastening is ensured due to the friction force, as well as the increased density of the array;
• fasteners for cellular and hollow materials. Porous substrates are characterized by low strength, so it is important to choose the correct hole diameter to ensure effective contact with the fastening unit. Nylon dowels, as well as liquid dowels, have proven themselves to be good for cellular bases;
• fasteners for drywall and thin boards. Sheet building materials are mounted to special profiles. As a result, a cavity is formed where the heat insulator is laid. The dowel clamp for such structures is called a butterfly. It has elongated slots. When screwing in the self-tapping screw, the sleeve takes on an umbrella shape.

When choosing a fastener to perform specific tasks, take into account the characteristics of the building material and select the correct fasteners, taking into account the method of fixation.

Types of dowels by installation method

Dowel bushings feature a design that allows for a variety of installation options:

The increased diameter of the self-tapping screw head allows you to reliably hold drywall and other types of sheet building materials that are attached using the through-hole installation method.

What material is the dowel plug made of?

Most fasteners are made from plastic. This is due to the low cost, availability, increased performance characteristics of the material, as well as the lack of the need to apply significant effort when screwing fasteners.

Various types of polymer materials are used for the manufacture of plastic retainers.:

• polyethylene. Easily deformable while maintaining integrity. It is lightweight and resistant to corrosion. Can be used when temperatures drop to 40 degrees below zero. Disadvantage: gradual loss of performance properties and cracking;
• polypropylene. It is used mainly indoors, as it is susceptible to negative temperatures. Advantages: increased hardness, wear resistance, and the ability to operate at high temperatures. The weak side is the appearance of cracks during long-term operation under temperature changes;
• polyamide. The material is also known as nylon. It is little subject to wear and is not afraid of mechanical stress. The nylon fastener is the most durable and reliable among other plastic fasteners.

Dowel for thermal insulation with a metal nail and thermal plug Strezzar Standard ST-M10x140 - 1

Along with plastic fasteners, metal products are used:

• of stainless steel;
• galvanizing;
• alloys based on brass or bronze.

Despite the increased strength characteristics and rigidity of metal fasteners, they are inferior to plastic in their ability to deform while maintaining integrity. At the same time, the metal is able to withstand increased loads. Protective coatings significantly increase the service life of metal dowel elements.

In what areas is the dowel anchor used?

Depending on the area of ​​application, dowel clamps are divided into the following types::

• standard. This is a universal fastener that is used in everyday life. Provides increased load-bearing capacity;
• special. They have a narrow purpose - they fasten metal-plastic, sheet insulation, drywall, cable boxes and pipes.

The design of the dowel fastening allows it to be used to solve various problems.

How to choose a metal expansion dowel and other types of fasteners

Guided by special tables, it is easy to select a clamp to perform specific tasks.

Please pay attention to the following points:

• base material. After performing test drilling, you can determine the type of building material by the color of the dust and the resistance of the tool;
• effective load. It is important to assess the magnitude and direction of the acting forces when selecting a clamp of the required cross-section and length.

The dowel clamp is a convenient and reliable method of fastening. It is important to be able to choose the right design and dimensions of the dowel, taking into account the tasks at hand. This will ensure reliable fixation for a long time.

Progress in the development of construction technologies concerns not only the creation of new materials and equipment, but also fastening elements. For example, dowels have become widespread.

A dowel is a spacer element, usually used when installing structures and elements to hollow or porous bases.

Consider a plastic dowel. The high efficiency of plastic dowels has been confirmed by leading construction companies due to their high fastening properties, ease of installation and external aesthetics.

The materials for plastic dowels are: polyethylene, polypropylene copolymer, nylon. These types of polymers are characterized by high strength and resistance to temperature changes in the range from -50 to +80 C°.

The first step in installing the dowel is drilling the hole. The diameter of the drill must be equal to the diameter of the dowel - the strength of the entire fastening depends on this. The drilling depth should be no less than the length of the dowel, plus a value slightly larger than the diameter of the dowel.

Drilling in dense materials, such as concrete, is carried out using a hammer drill. For more porous materials, using a hammer drill is not recommended due to the hole breaking.

Dowel parameters

Dowel		Hole for dowel		Screw diameter
diameter, mm	length, mm	drill diameter, mm	drilling depth
5	25	5	30	3,5 — 4,0
6	30	6	36	4,0 — 5,0
6	40	6	46	4,0 — 5,0
6	50	6	56	4,0 — 5,0
8	40	8	48	4,5 — 6,0
8	50	8	58	4,5 — 6,0
8	65	8	73	4,5 — 6,0
10	50	10	60	6,0 — 8,0
10	80	10	90	6,0 — 8,0
12	60	12	72	8,0 — 10,0
14	70	14	84	8,0 — 10,0

Dowel screws vary in length, diameter, and slot type. Read more about screws in the article “About screws and self-tapping screws.”

Main types of dowels

The universal dowel with increased elasticity is made of polypropylene. When it enters the cavity, the dowel is wound around the screw and forms a knot.

Also, for a hollow base, a butterfly dowel is used. The principle of fastening is shown in the figure.

Facade dowel. Used for fastening thermal insulation during facade work.

A variety of dowels are used today in construction and operation, each of which has its own distinctive properties and scope of application. To learn more about them, you should carefully study the features and modifications, as well as see an overview of the most popular and popular products.

If you want to know how to do it correctly, watch the video.

It is a fastening element consisting of 2 parts - a plastic spacer shell and a metal screw. Most often used for fastening objects to solid products and materials - stones, bricks, concrete structures. To check the quality, you should carefully inspect the dowel nail for cracks and symmetry, paying special attention to the strength of the plastic shell.

Prices

The minimum price of the product is 174 rubles. for 1 package (100 pcs.), and the maximum is 856 rubles. for 1 package (100 pcs.).

This fastening material is a product used for reliable fastening of structures and objects in solid and solid concrete and wooden structures - bricks, reinforced concrete, natural stoneto me. The main parameter of its quality is a durable plastic shell made of nylon material, as well as reliable galvanized steel. When purchasing, it is advisable to see the quality certificate for the product.

Prices

In Russia, the price range for dowel screws ranges from 42 rubles. for 100 pcs. up to 460 rub. for 100 pcs. depending on the diameter and length of the product.

This product is a fastening system that includes a polypropylene ribbed element and a metal (or plastic) screw with a wide pitch. An expansion dowel is used to securely connect self-tapping screws to a load-bearing base - concrete, stone or wood. This fastener is also used for attaching drywall, plywood or aerated concrete. To check the quality of the fastener, it is tested for bending, which should be minimal.

Prices

In our country you can buy an expansion dowel from 22 rubles. for 100 pcs. up to 100 rub. for 100 pcs.

This interesting and very important fastening element is used to securely connect wires to a load-bearing surface - a wall, ceiling or rail. The dowel clamp is a reliable PVC product, which is made in the form of a loop with growths at the end. Having strengthened the bundle of wires, the dowel is driven into the pre-drilled hole with light movements, securely fixing into it.

Prices

The minimum price of the product is 101 rubles. (for 100 pieces), and the maximum is 148 rubles. (per 100 pcs).

This cre The pinning mechanism consists of a plastic shell and a steel insert in the form of a screw, which is screwed in and pushes the plastic shell apart inside the product. Most often it is performed with a flange, which prevents the screw from being buried inside the wall. Used for fastening in brick and block structures, monolithic reinforced concrete walls, wooden products. To check the quality, you should carefully inspect the product visually - there should be no cracks on it, steel self-tapping screws should be without nicks.

Prices

In our country, the minimum cost of dowel screws is 120 rubles. (for 200 pcs.), but the cost can also reach 360 rubles. (for 200 pcs.).

Represents PBX or nylon shell that has a hole in the inside and gripping ribbed edges and hooks on the sides. Used as a reliable fastener for connecting structures and attaching additional elements to stone, concrete or brick walls. To check the good quality of plastic dowels, it is best to test them in practice - they should not bend or crack during operation.

Prices

You can buy a plastic dowel for a price starting from 30 rubles. (for 100 pcs.) up to 200 rub. (for 100 pcs.).

This product is widely used for fastening thermal insulation boards - polystyrene foam, polystyrene foam, mineral wool panels. The thermal insulation dowel is a plastic product with a very wide cap on one side, thanks to which the thermal insulation material is securely attached to the load-bearing surface of the wall. To check the quality of products, you must have a certificate that certifies the technical compliance of the product.

Prices

Today, a dowel for thermal insulation can be purchased at a price of 26 rubles. (for 10 pcs.) up to 240 rub. (for 10 pcs.).

Video

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