Which self-tapping screw for the dowel 8. How to choose the right drill for the dowel for fastening various objects

December 10, 2017

A dowel and a self-tapping screw are two elements that complement each other, if the task is to connect some kind of rigid structure to a solid solid wall: concrete, brick, assembled from foam blocks, finished with drywall. If the wall was wooden, then you can do without the dowel, because the screws are easily screwed into soft wood, where they are firmly fixed. The selection of one to the other is based on the dimensions: the length and diameter of the self-tapping screw and the length and inner diameter of the dowel. It will also be necessary to take into account the thickness of the fastened material.

The situation when the wrong choice is made is not common, but such cases are known. If the selection was made incorrectly, for example, the inner diameter of the dowel was chosen less than the diameter of the self-tapping screw, then the latter simply breaks the first one. If everything was done the other way around, then the fasteners will hang inside the plastic insert, while it will not be unlocked, which is why the strength of the fastener assembly will drop sharply. The same can be said if the self-tapping screw does not reach the bottom of the dowel with its end.

In general, it is necessary to approach the selection process correctly. And for this you need to start with the dowel. The larger it is, the greater the load it can withstand. Here, the loads are distributed in this way relative to the dimensions of the plastic insert.

If the loads are small, then you can use a dowel with a diameter of 4-5 mm.
If the loads are medium, then it is better to choose an insert with a diameter of 6-8 mm.
With very large - 14-16 mm. For example, when scaffolding is assembled.

But here it is necessary to take into account the density of the material where the fasteners will be inserted. The higher the density, the more loads the mount will withstand. Therefore, dowels with self-tapping screws inserted into concrete products withstand the largest loads with their small sizes.

So, the dowel is selected in size, now a self-tapping screw is also selected for it. Here are just a few of the ratios.

Now we need to match the lengths to each other. The length of the dowel is selected according to its diameter.

How to choose the right drill for a dowel for fastening various objects

The main thing here is not to make a mistake, because several lengths fit the same diameter according to the standards. For example, a dowel with a diameter of 6 mm can have a length of 25 to 50 mm with a gradation of 5 mm.

As for the length of the self-tapping screw, it depends on the length of the dowel and the thickness of the attached material. This takes into account that the thickness of the attached material depends on the density of the base to which it is attached. If fastening is made on a loose surface, then the thickness of the attached material should not exceed the length of the dowel by 35%. If the base is dense, then the thickness should not exceed 60% of the dowel length. It is necessary to drill a hole in the supporting structure a little more than the length of the dowel, and the self-tapping screw can be screwed in to the end. Even if its end pierces the insert, but that's okay.

How to choose a dowel for a self-tapping screw

For the correct and high-quality fastening of various building materials using self-tapping screws, it is important to select a dowel that is suitable in size and quality characteristics.

The dowel, although it is an auxiliary fastener, nevertheless plays a very important role in the reliability and strength of the fastened structures.

Dowels are made from a wide variety of materials, it can be various types of plastic (polypropylene, nylon, polyethylene, etc.), they can also be made of various metals - iron, brass, stainless steel, etc.

There are different types of dowels that are designed for fastening in walls made of brick, wood, drywall.

For example, dowel type "K" is fixed in concrete:

Dowel type "T" is designed for fastening in walls made of weak concrete and brick:

The dowel type "S" is fastened in many materials from various bricks and concrete:

The dowel type "U" is a universal dowel made of polypropylene, which fastens both in solid and hollow materials very securely:

The dowel "KPU" is a dowel made of nylon, very resistant to temperature extremes and various mechanical deformations:

The dowel "KPW" is also made of nylon and is designed for plasterboard and chipboard materials, as well as for concrete and brick (solid and perforated):

The dowel "KPX" is used for fastening in solid building materials such as brick, stone, concrete, as well as in hollow blocks, etc.:

The dowel "KPR" is used for fastening in hollow building materials: aerated concrete, hollow block, lightweight concrete, window frames, etc.

Dowel "KMG" performs anchoring in aerated concrete and other materials:

The foam concrete dowel provides a strong anchorage with this porous material:

Dowel "Driva" is designed to fix various fixtures on drywall with a thickness of at least 9 mm:

Dowel "Butterfly" is a special dowel designed for fastening to drywall, GVL, chipboard and other building materials with a thickness of 10 - 12 mm:

All these dowels are firmly attached to the wall due to their special design, which provides for a spacer part in it, the diameter of which is less than a properly selected self-tapping screw.

Therefore, when the self-tapping screw is screwed into the dowel, the expansion part expands, forming a strong, reliable connection with the wall.

Below you can see a table that will help you choose the right screws and dowels in accordance with their length and diameter. Also in this table there is data on the diameter of the drills and the depth of drilling in each case.

To select a self-tapping screw to the dowel, you need to pay attention to two parameters:

screw length
screw thickness

The length should be such that the self-tapping screw, when fully screwed into the dowel, has a protrusion from the self-tapping screw a few millimeters (3-7) less than the thickness of the material that needs to be fixed, taking into account the fasteners you need (sunk, flush or other)

The thickness of the self-tapping screw should be such that the working surface of the dowel diverges in breadth, but in the meantime the self-tapping screw itself rotates with a certain little effort until the very end without applying much force.

Also pay attention to the thread itself, it should be just such that it is screwed tightly into the dowel, since it is possible to pull out the self-tapping screw from the dowel.

To fasten various building materials to building structures in modern construction, fastening with dowels and self-tapping screws is often used.

A self-tapping screw is selected for the dowel of a certain diameter you have chosen, which enters the inner hole of the dowel with a slight stretch, that is, the self-tapping screw must be smaller in diameter than the outer diameter of the dowel, approximately 1.5 - 2 mm, and must be equal to the inner diameter of the dowel hole.

The length of the self-tapping screw should be equal to or slightly more, up to about 5 mm, the length of the dowel.

The hole for the dowel is drilled the same diameter as the dowel you are using.

The depth of the hole is 5-6 mm longer than the dowel, so that the self-tapping screw is completely wrapped in the dowel, and its tip does not rest against the building structure in the hole. Good luck.

Which dowels are better

Which dowel to choose is a rather trivial question, which in fact has an unambiguous answer: the dowel must be chosen one that matches the material of installation and the type of installation. How many times will the master curse the scrolling self-tapping screw when installing the eaves on the foam concrete partition of the house of the 1-LG-600 series? How many people wrap the unfortunate dowel with electrical tape, put on it a cambric from the cable, put on a heat shrink tube - and all to no avail!

Who would guess to put two or three pieces in a row and scroll through so that they do not turn? And how many will use a special expansion dowel for gas and foam concrete, not to mention the fact that few people suspect, and even more few know for sure that such a dowel exists in nature! But a single classification of dowels, reflected in any regulatory documents, just 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 dowels are in principle:

According to the principle of action:

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 expansion dowel rest against the walls of the hole and wedged in it. They are intended for solid materials (concrete, reinforced concrete, asphalt, even wood and wood-based materials).

2. Anchor, which, in addition to wedging in the material, are also capable of deforming so that the back of such a dowel cannot pass into the hole (anchor principle). Such dowels are designed for hollow and porous materials (hollow brick masonry, aerated concrete, foam concrete, etc.), as well as sheet materials like drywall.

According to the installation method:

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

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

They also share through installation, in which part of the dowel is passed through the structure to be fixed (has an elongated non-expansive part) and preliminary, in which the dowel is placed in the hole for 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:

1. With a side (cuff) - when twisting, the side wraps around the screw (self-tapping screw).

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

By purpose, scope and design features:

1. Standard dowels for solid materials - the most common type of this type of fastener. The classic version is made of nylon (polyamide), and most of all it is 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 fastener is suitable in most cases for most materials.

How to choose a self-tapping screw for a dowel

However, nylon has one very unpleasant feature - at low temperatures, its strength increases dramatically, and the viscosity decreases. Therefore, when working "on the minus" in the open, there are frequent cases of ruptures of nylon dowels (especially when using dowel-nails), as well as cases of impossibility to screw a self-tapping screw or screw into them to the end.

However, practice has shown that it is better to use a brittle nylon dowel than a tough polyethylene one made at the lowest quality level. In extreme cases, you can use an industrial hair dryer, making installation in a warm stream of air.

2. The dowel for aerated concrete and foam concrete has the ability to wedged in the hole, being held with the help of special spiral ribs. A hole for it is drilled according to the diameter of the core, and then the dowel is hammered and a screw is screwed into it.

3. Frame dowels are available both for solid materials and for 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.

4. Adjusting dowel allows you to fix the structure at a certain (up to 30 mm) distance from the base; consists of two parts, one of which is designed for the base, and the other for the attached structure; also comes with a special screw. Designed for fixing various battens for sheathing with sheet and / or panel materials.

5. The universal dowel is convenient for fastening both to cellular, slotted materials like hollow bricks, and to hollow partitions made of plasterboard, false ceilings of various types. It is arranged as follows: when a screw is screwed in, the dowel material, as it were, "remembers" the presence of a hollow space around itself and, accordingly, deforms 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 together with the dowel, and then fold back like spacer springs in spotlights, resting against the inner surface of the sheet.

6. Dowel for gypsum plasterboard and porous concrete (“pozidriver”, “jet-plug”) is used for static fixing of hinged structures, as well as paintings, etc. on walls and ceilings made of gypsum plasterboard, LSU, MCL and similar materials. It is twisted at the base with a screwdriver or a screwdriver, as it has a pozidriv (PZ) type slot in the front part, and in the “wrong side”, that is, the back part, sharpening along the profile of the first drill, going to the cone.

"Pozidrivers" (that's how we called these dowels, from the bourgeois name "pozidrivers", painted on 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 boards and similar materials, while a silumin dowel is used for gypsum boards, gypsum, chipboard and cellular concrete. Self-tapping screws for them are included, but they are usually of lousy quality.

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

7. The soundproof 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 strong). The inner part (which is threaded) has the shape of a cone, and from the outer part, deep notches are applied to the sleeve. Available in sheet steel, carbon steel or stainless steel, also without thread, such as HILTI HKD-S.

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

Finally, disc-shaped dowels used for fixing heat-insulating plates 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 fully used in separation from the other).

Variety of fasteners

Today (and, by the way, in all centuries) when carrying out various repair construction or finishing works, it is simply impossible to do without the necessary fasteners. Yes, and in everyday life, such fasteners are also useful - hang a picture, fix a shelf, strengthen a cabinet, etc. There are a large number of different types of fasteners that have different design features and are used to solve relevant problems, ranging from fixing a board with an ordinary nail to installation of a complex anchor with increased reliability.

Fixing baseboards, laying wooden floors, installing door and window frames, installing plasterboard sheets on walls, arranging suspended ceilings, manufacturing and assembling various types of indoor and outdoor stairs - this is not a complete list of areas for using modern fasteners. The total cost of fasteners used in the work is about 1% of the total budget for repair or construction work.

The correct choice of the necessary fasteners ensures a long and reliable operation of the connections made. Therefore, let's deal with their main types.

self-tapping screws

Based on the name of this fastener, in most cases (but not all) it is able to cut the necessary holes and grooves in the fastened material itself.

They are classified into the following groups:

1. By type of material to be joined:

wood screws (smaller pitch);

self-tapping screws for metal (larger step).

Note that self-tapping screws for metal are made of two types - self-drilling and those for the use of which you first need to make a hole in the metal. The former have a small drill at the tip, the dimensions of which are selected for a specific thickness of the metal. A prominent representative of the second type of self-tapping screws is fasteners for arranging plasterboard structures.

2. By size.

Naturally, the diameter and length of the self-tapping screw must be selected based on the specific conditions of its use.

3. By appointment.

roofing fasteners. They have a wide cap with a press washer, which completely seals the hole made to prevent moisture from entering. They are presented in a large assortment on the site http://ms37.rf/crepej;

general purpose screws, such as drywall screws.

How to choose a self-tapping screw for a dowel?

Anchors: application and types

We note right away that today a large number of people are trying to use such fasteners for absolutely other purposes. For example, quite often they try to fix objects on brick walls with anchors. As a result, the product still does not hold, large holes remain in the wall, not counting the time and effort spent.

Once and for all, it must be noted that the anchor bolt and anchor rod can only be used for concrete surfaces, and in other soft materials they simply scroll.

Types of anchors (by type of external part):

1. Mounting anchor.

This is a universal fastener.

2. Anchor hook.

On such anchors after fixing, you can hang overall objects.

3. Anchor loop.

For the loop of such an anchor, you can cling to something.

Varieties of anchors according to the design of the hidden part (the principle of bursting):

The anchor has a bolt with a wedge at the end (they are tightened with a nut).

The anchor wedge itself is a nut (the nut is tightened with a bolt).

Anchor sizes can vary from the smallest with a length of 50 mm (diameter 6…8 mm) to 400 mm (diameter 22 mm).

Anchor installation:

Proper selection of a drill bit for a drill and drilling a hole. Note: if you have chosen an anchor with a diameter of 10mm, then you need to make a hole of exactly 10mm. If, for example, we take 12 mm, then as a result the anchor will not be clamped, and, naturally, no winding of various materials on the anchor will help either.

Installing an anchor in a hole.

Clamping the anchor with an open-end wrench or screwdriver.

Rivets

They are the simplest fasteners for the permanent connection of sheet iron, tin and other thin-sheet materials, such as plastics or leather. They provide high strength of the connection, however, such a connection can be disassembled only if the rivet head is cut off.

The rules for selecting thickness and length are usually indicated on the packaging of fasteners.

Dowels: varieties and applications

Today, hardware stores offer 3 main types of dowels:

1. Metal dowel.

A metal dowel is the simplest and oldest type of fastener. It can be mounted on almost any surface. But still, it is not advisable to use a hammer in every case; sometimes it is worth loading such a dowel into a cartridge, electric or pneumatic pistol. Metal dowels differ from each other only in diameter and length.

2. Mounting dowel with plastic plug.

Mounting dowel - the most common type of dowel. It is produced in two versions, which differ only in the shape of the plastic cork used (more specifically, in the shape of its outer rim). In one case, the dowel is installed in a recess, and in the other case it is not (the cork of the second dowel is equipped with a fungus cap).

Such mounting dowels are installed using a puncher (making holes) and a hammer (the plastic plug is hammered first, and then its metal part). Note that the metal part of the dowel, if necessary, can be easily unscrewed from the plastic cork with a simple screwdriver due to the applied thread. The diameters of such dowels vary from 6 to 14 mm, in length - from 35 to 250 mm.

3. Expanding dowel.

Scientifically, it is also called the Bierbach dowel.

This fastener is entirely made of metal and consists of 2 wedges, which are movably connected to each other by a special washer on one of them. It is mounted in a pre-made hole, where it is wedged with a hammer blow. For suspended ceilings, this is the best option.

Dowel screw

A dowel-screw is a type of fastener used to secure certain parts, structures, individual objects in solid solid surfaces.

Features of the use of dowel screws

Dowels secure self-tapping screws, bolts and screws in the structure. The specificity of the work of the dowel-screw is in the process of rapid friction, when the dowel steams the screw, nail, screw. The device of the product is indicated by two elements:

non-distorted - a zone that does not take part in the installation process;
spacer - a part that changes dimensions when connected.

Some types of dowels are produced with a cuff, which prevents the product from falling into the hole. The design of fasteners is held inside the hole due to tightly pressed walls or due to differences in modification.

Previously, installers used wooden chopsticks to fix the elements. To date, an extensive range of dowels is produced (according to GOST standards), intended for use in "tandem" with any materials. For the manufacture of fasteners, metal, plastic (polypropylene, polyethylene) are used. The most popular is the quick universal nylon driven dowel. Installation is carried out by impact. Such dowels, together with self-tapping screws, can be used to fasten, regardless of the wall material.

For drywall, metal and plastic dowels are equally suitable. The product is designed for mounting the necessary elements on the surface of gypsum fiber, drywall, porous concrete. Plinths, windows, battens are fixed with a nail dowel-screw. A similar dowel is supplied with a knurled nail. The facade dowel used for fixing and holding the insulation is equipped with a wide hexagonal mushroom head. Design features provide the necessary insulation of the joints, preventing the ingress of moisture, dirt. For fastening window frames, door frames, a frame dowel with a countersunk screw (screw) is used. The dowel-clamp used for attaching wires and pipes to foam concrete, concrete, brick, is simple, convenient, and reliable installation without the use of additional fasteners.

The dowel screw is one of the most common fasteners. Depending on the characteristics of the load, the nature of the base, the type of fastening directly, a certain type of dowel is selected.

How to choose a drill for a dowel

Be sure to determine which screws, nails, screws are suitable for the selected dowel (if the dowels are not equipped with screws). Together with the dowels, the kit comes with an installation diagram, recommendations for selecting the appropriate screw. For the correct choice of the dowel, it is necessary to take into account the diameter, the length of the screws, the thickness of the element mounted on the dowel.

The choice of dowels, believe me, is huge. Which one to choose in each case?

We offer for sale and keep a constant warehouse stock of a wide variety of types of dowels. Here are some of the most common dowel designs:

Polypropylene dowel spacer (with a mustache) is designed for fixing various elements using self-tapping screws and universal screws in concrete, brick, stone. Production material - polypropylene or nylon.

Expansion dowel(type "hedgehog") is also designed for fastening various elements to a concrete surface and have a kind of spacers for better fixation. Produced from polypropylene.

Drywall dowel "DRIVA", there are plastic and metal, they are intended to fasten various elements and structures in soft materials - gypsum plasterboard and gypsum fiber sheets (GVL), porous concrete, using self-tapping screws and universal screws.

This dowel is made of zinc-aluminum alloy or nylon. Metal Driva due to the tip in the form of a feather drill, as a rule, is installed without pre-drilling a hole for it. A large thread on the outer surface of the dowel body makes it possible to screw it into the wall with a screwdriver.

dowel nail designed for fast fastening of windows, metal profiles, various battens and rails, beams, skirting boards, plywood, cable channels, etc. into concrete, stone, brick. when you need to install them quickly and in large numbers. The dowels are completed with a nail having a knurled hold in the form of reverse cones. The design of the dowel-nail is made of polypropylene or nylon, and the nail, respectively, of steel. The nail is driven in with a hammer.

But in order to make the right and competent choice, call the office of our company, leading experts will help you and give you the most comprehensive information on the conditions of fasteners you need.

Standard nylon dowel suitable for any wall and used with a self-tapping screw with a diameter of 2 to 16 mm. A hole is drilled in the wall corresponding to the diameter of the dowel, in which it is held due to the directed antennae, and when wedging with a self-tapping screw, the dowel is “tightly” attached to the walls of the hole.

Dowel for aerated concrete, for such a dowel, a hole corresponding to the diameter is drilled. The dowel is held in the hole by wedging under the action of a self-tapping screw and its spiral ribs.

Frame dowel It happens in length from 60 to 360 mm., Two main types - for a solid solid base and for hollow (slotted) and soft materials. The elongated expansion part of the dowel provides engagement with several jumpers at once in a material with voids. As a rule, they are used for fastening window and door frames, as well as through a layer of plaster and thermal insulation, various cladding elements.

Remote(adjusting) dowel, fixes the laths of the crate for subsequent sheathing at some distance from the wall. Allows adjustment within the range from 0 to 3.00 cm relative to the base of the position of the lathing laths during fastening due to the dowel divided into 2 parts (1 - base, 2 - lath) and a self-tapping screw of a special design.

Universal nylon dowel

Rabitz

Netting mesh produced by our factory can be made of black or galvanized wire up to 4 mm in diameter with mesh sizes from 20x20 to 90x90 mm. Roll height up to 3 meters. Metalware Plant No. 2 sells mesh netting wholesale and retail (delivery is possible). Production of chain-link mesh of non-standard sizes to order. ZMI - 2 also produces mesh "RABITSU" with PVC coating different colors (in stock and on order). All information about chain-link mesh: history, production, application

Our factory offers you untreated galvanized wire various diameters in any quantity. for more detailed information, please contact the central office by phone: +7 (495) 645-97-55

Chain link fence sections

Welded fencing sections

Various types: You can choose one of the options offered by us or order the production of welded fencing sections from us according to your own sketches or drawings. Such fences are suitable everywhere: from fencing a front garden in a country house to restricting access to construction sites for unauthorized persons.

made of galvanized metal sheet with a thickness of 0.5 mm. up to 1.0 mm. method of simultaneous cutting and drawing.

self-tapping screws

Metalware Plant No. 2 offers various purposes and with various coatings: oxidized, galvanized, yellow-pasted self-tapping screws. Self-tapping screws with frequent threads are used for fastening thin metal parts to plastic or wood. Self-tapping screws with coarse thread are used for fastening wooden parts, insulation, fiberboard, etc.

Nails

Metalware Plant No. 2 manufactures and sells a variety of nails from the simplest construction to ruffed nails, including slate ruffed ones. The whole range of nails You can purchase at our retail outlets or in bulk through our office in Moscow.

Furnace casting

If you need cast iron products for furnaces who are commonly called , then it's up to us!
Cast iron is used to make both small collapsible stoves "potbelly stoves" for summer cottages and gardens, as well as individual parts and accessories for stoves.
Cast iron at high temperatures, it is strong enough, not subject to corrosion and deformation, durable.

Bolts and nuts

Other fasteners and hardware

Metalware Plant No. 2 offers a wide range of other fasteners and hardware, namely: bolts, nuts different sizes, washers, rivets. Our factory sells such rarely offered sale hardware, as a welded chain (without quality control), carabiners.

Most people sooner or later wonder how to choose a dowel for a self-tapping screw when attaching a structure to a concrete, brick, aerated concrete surface or drywall. In such a matter, with the help of one self-tapping screw, without the use of a dowel, the problem cannot be solved.

Two products complementing one another: a dowel and a self-tapping screw. Basically, these two elements are used in fastening to a solid surface. When working with a wooden surface, you can not use the dowel due to the fact that the screw is screwed in lightly and is well fixed in soft wood. The main factors in the selection of dowels and self-tapping screws are the exact selection of products in terms of size, length, diameter and length of the inner circumference of the dowel.

There are cases of unsuccessful selection of these two components to each other. If this happened and the choice is wrong, for example, the diameter inside the dowel turned out to be smaller than the circumference of the self-tapping screw, the second element of the first may break and the fastener will be loose in the plastic insert. Expansion will not occur and the strength of the fasteners will become low. The same situation will occur if the self-tapping screw does not reach the bottom of the dowel with the help of the end.

What is important to consider

It is very important, in the selection process, to correctly designate the sequence. To begin with, a dowel is selected. The larger it is, the greater the load it can withstand. It is necessary to take into account the circumference and length of the product, both the self-tapping screw and the dowel. For small loads, a dowel with a circumference of 4 - 5 mm is used. 6 mm and 8 mm for medium, 10 mm and 12 mm for heavy loads, 14 mm and 16 mm for very heavy loads, for attaching scaffolding, etc. You should also take into account the density of the material in which the dowel will be located. The stronger the material, the more load the dowel of the same size can withstand.

The strength of the material used, where the fastener is used, is always taken into account. The higher the seal, the greater the load the fastener can withstand. Two elements inserted into the concrete surface are able to withstand a significant load, despite their small size. After selecting the dowel of the required size, a self-tapping screw is selected for it. When choosing a self-tapping screw, it is desirable to rely on several criteria:

The thickness of the self-tapping screw should be so that it is not loose inside the dowel and is tightly fixed. It takes a little bit of force to screw it in until it's installed.

In length, the self-tapping screw must be similar in length to the dowel, or exaggerate by 5 millimeters, but no more. When attaching any thing to the wall, use a longer length.

It is difficult to determine the carving because of their diversity. During a mismatch between two elements according to the type of thread, there is a possibility that the latter will fall out or not be screwed in at all.

Correspondence table for dowel with self-tapping screw

Dowel diameter in mm Self-tapping screw diameter in mm

5mm 2.5mm. (from 2 mm to 3 mm.)

6 mm. 4 mm. (from 3.5 mm to 4.5 mm)

8 mm. 5 mm in diameter. (from 4.5 mm to 5.5 mm

10 mm 6 mm. (from 5.5 mm to 6.5 mm)

12 mm, 8 mm. (from 6.5 mm to 8.5 mm)

14 mm 10 mm. (from 8.5 mm to 10.5 mm)

16mm 12mm. (from 10.5 mm to 12.5 mm)

First, we will select the desired size of the dowel, and then we will select the required circumference of the self-tapping screw. The main thing left is to choose the required length of the screw.

We take the selected dowel length, add the width of the material used in the mount. This is the required length of the screw. For loose substrates, fasteners with a thickness of more than 35 percent should not be taken, dense substrates should not process fasteners more than 60 percent in thickness.

It is allowed to leave the dowel a little for the self-tapping screw, this is not dangerous, the most important thing is that it must reach the end of the dowel and open it to the fullest in order to firmly mount it. If the fastening element does not reach the end, the dowel will have a turning ability and the installation work will become unusable. It is necessary to prepare a hole for the dowel a little more than its length and circumference.

In fastening various building materials to a building structure, fastening with a dowel and a self-tapping screw is often used. For example: We need to attach a plywood sheet 20 millimeters wide to a concrete floor. We will need an 8x50 dowel (according to the table above, the diameter and length correspond), as well as a 5x70 self-tapping screw (5 is the circumference of the self-tapping screw, 70 is its length). To drill on, you will need a drill 8 by 110, you need to drill deep, not less than 60 millimeters. After the drilling procedure, remove the dust from the hole, insert the dowel, then screw the self-tapping screw into it, and it goes further through the plywood sheet. A self-tapping screw with a high screw thread has a thin and sharp profile. Self-tapping screws used in fastening various kinds of metal parts have a more frequent thread. Double thread.

A dowel-screw is a fastener used to fix various products in a solid base. The principle of operation is based on the friction force that occurs when a screw is screwed into the dowel.

Brief historical background

The name of the dowel's inventor and the date of its invention are unknown. But January 14, 1913 is the day the Englishman John Joseph Rawlings received a patent for this fastener.

The first devices of this kind were made of wood. Today, polyethylene, polypropylene and metal dowels are produced.

In addition, the use of nylon dowels is widespread - their use allows you to solve many problems. These fasteners complete with screws are appropriate to use when working with any material.

Description

Nowadays, no repair work can be imagined without the use of dowels. You always need to attach something to a wall or ceiling surface. Only if the walls and ceiling are made of wood, you can use nails and a hammer. In all other situations, dowel fasteners are indispensable.

There is a wide range of similar products on sale, differing from each other in the material of manufacture and the method of retention. In addition, the weight and size of the dowel-screws can be very different.

The mounting dowel can be not only polypropylene, but also nylon. The use of the former is possible only in interior decoration, since sub-zero temperatures contribute to the formation of cracks on them. And nylon fasteners are equally well suited for both indoor and outdoor use.

The expansion dowel is used when fastening structures to hollow blocks, concrete and brick. Fixation occurs with the help of special antennae. They securely hold the dowel and prevent it from turning. There are separate types of dowels designed for a construction gun. Despite the different installation method, they are quite effective.

The specifics of the dowel-screw

As you can see in the photo of the dowel-screw, it can be either with or without a locking collar. The dowel with a shoulder is usually made of nylon. It is used in outdoor installation work. The stoppers hold fasteners, preventing them from falling into the hole.

The fastener without collar is made of polyamide. Its distinguishing features are a through hole, longitudinal ribs and a non-expansive top. Such a design solution greatly simplifies screwing in, increasing the degree of expansion of the dowel.

And the fixed top protects the plastered surface from cracks. In addition, collarless fasteners are resistant to atmospheric precipitation and their service life is much longer.

- This is a specialized fastener used for mounting and fixing various structures to the walls of buildings. The most popular are dish type products.

The dowel-screw for drywall can be either plastic or metal. Its purpose is to fix products on plasterboard or gypsum-fiber sheets and porous concrete.

Metal fasteners do not require pre-drilling holes - they have a feather drill at the end, and the spacers are threaded. Installation of such a dowel occurs with a screwdriver.

The principle of operation of a universal dowel-screw in a thick wall is similar to the principle of operation of a conventional spacer. If the wall is thin, then after passing it, the dowel is screwed onto the screw and tied into a knot, which makes the fastener as reliable as possible.

The scope of the mounting dowel-nail is the quick installation of a double-glazed window, plinth, lathing, etc. The component is a nail that has a knurled thread with a reverse cone for better fixation. For its installation and a screwdriver and a hammer.

The purpose of the adjusting dowel is to fix wood products during the internal arrangement of buildings. It allows you to do without the use of pads and wedges for leveling an uneven wall surface.

For the installation of household appliances, it is permissible to use the fasteners supplied with it. They are calculated with the required margin of safety. When choosing dowel-screws on your own, you must take into account the mass of the load and the material of the wall.