Anchor bolts for which a half bushing is needed. Anchor bolt: types, application and installation features

Anchor bolts— if we consider the principle of operation of the two main types of fasteners - the anchor and the dowel, then the anchor has a significant advantage. The metal anchor, in addition to the frictional force, is held at the base using a “stop” in the form of a kind of anchor, obtained due to the spacer part of the shank. To friction is added the force of resistance to destruction of the base material.

There is also chemical anchors, they use quick-hardening adhesives instead of a metal sleeve, which are introduced into the hole before installing the anchor bolt. The result is a monolithic connection with the base.

There is a large range of anchors on the market, but they can all be divided into several classes.

Anchor bolt with nut: how to fasten

Essentially, it is a stud with a nut and washer that is screwed into a coupling (threaded sleeve). Therefore, it can be called an anchor bolt with a nut or a stud anchor. We study in detail how to fasten anchor bolts with a nut ourselves and use them.

Anchor bolt (foundation bolt) with nut

On one side, a nut and washer are screwed onto the stud, and on the other, there is a “wedge” in the form of a cone. In the wide part the wedge corresponds to the diameter of the coupling, in the narrow part it corresponds to the pin. The coupling on the wedge side has a notch and longitudinal slots.

Installation is quite simple, even a beginner can understand how to attach anchor bolts with a nut.

Anchor bolt: fastening diagram

A hole for the coupling is drilled in the base and cleaned of dust. The part is hung on the anchor, inserted into the hole and hammered in with gentle blows of a hammer until it stops. Then tighten the nut a few turns.

Screwing onto the stud, the nut “unscrews” it from the coupling; as a result, the wedge expands the coupling along its entire length with slots.

Anchor bolts are made from galvanized steel. Used for concrete, stone, solid brick.

There is an “improved version” of such an anchor - a double-spacer one.

Double spacer anchor bolt

It has two movable couplings with slots, one of which fits into the other with a cone. When the nut is screwed in, the shank pushes one sleeve onto the other. The first one expands with a wedge cone and itself expands the middle coupling, forming two fastening belts.

Wedge anchor - how to attach

This type can be considered as a modification of the previous one. The coupling is made in the form of a movable short sleeve-ring at the end of the pin on the shank (wedge) side.

The principle of operation is similar, there is a slight difference - it does not require precise drilling to the depth of the hole and cleaning it from dust. The hole is drilled with reserve, the anchor is inserted to the required depth and the nut is screwed in, pushing the sleeve apart with the shank.

Anchor stud with hex head

This is a classic bolt and washer that screws into a coupling with longitudinal slots at the end. The tail cone-shaped nut serves as a spacer element.

Installation is standard - drill a hole, clean it, insert an anchor with a suspended part and lightly tap it. All that remains is to tighten the anchor bolts a few turns - the nut fits into the coupling with a cone and pushes it apart.

Anchor stud - installation diagram

The scope of application is the same as that of previous types - fastening heavy structures to a base made of concrete, stone and solid brick.

This type of bolt may end in a ring or hook. They allow you to simply hang structures after installing the anchor, otherwise there are no differences.

Impact anchor bolts - how to attach an anchor bolt.

This sample combines the functions anchor and nail.

Impact type stud anchor

It consists of a hollow metal rod, one end of which is made in the form of a stud with a thread for a nut and washer, the other is a sleeve with a four-leaf spacer.

Installation, how to fasten an anchor bolt - you need to drive an anchor bolt into the hole in the base, into which in turn a nail is driven. The petals of the sleeve diverge. The nut serves only to secure the part being hung.

Four-segment expansion anchor

According to the principle of operation, this type is closer to an anchor with a nut or hex head. Although it does not have a wedge or cone-shaped nut on the shank of the stud or bolt, expansion occurs due to the bolt itself being screwed into the hollow sleeve, which moves the internal tetrahedral element.

Four-segment anchor bolt

The anchor consists of a cylinder with four slots that end in a narrow ring. The slats are held in place by a flat spring, after which the slots are shaped like a wedge. Moving, the tetrahedral threaded element pushes these wedges apart.

Anchor stud installation diagram

The bolt is not included in the kit, but is selected depending on the size of the structure being hung.

In addition to the bolt, you can screw a bolt with a hook or ring into the expansion anchor. These modifications come with them.

Due to the wide opening of the wedge lamellas, expansion anchors can also be installed in weak foundations - hollow (slotted) bricks, gas or foam concrete blocks.

Driven anchor - how to attach an anchor bolt.

One of the easiest types of anchor to install.

The device is a threaded bushing that has slots at the driven end, a conical internal shape and a wedge.

Installation - a hammer anchor is inserted into the prepared hole and, using a special impact attachment, the cut part is pushed apart with a wedge. When the anchor bolts are screwed in, the petals spread even wider, increasing grip.

Made from galvanized steel or brass.

Screw anchor

Has a special design. The slots in the sleeve are not cut completely and end with a ring with a nut. Closer to the head and in the middle of the liner, the lamellas are weakened. When tightening the screw, the nut moves and pushes the lamellas apart in the middle.

Specially designed for weak and hollow substrates. It can be produced not only with a screw, but also with pins, hooks, and rings.

In order to correctly install anchor bolts, it is necessary to take into account the type and strength of the base, select the optimal type of anchor for a particular part and determine its load capacity.

And although some types do not require high precision hole drilling (for example, expanding), the more accurate it is, the more reliable the anchor’s adhesion to the base.

Information to note : , , .

Who has not heard such names as the Wright brothers, Thomas Edison, Sergei Korolev. These inventors and designers went down in history thanks to their intelligence. There are personalities known only in a narrow circle, such as Brighton, who invented Some are undeservedly forgotten, the inventions of others bring glory to the creator, like the well-known Rubik's cube. But there are more things, more people, than a toy square. If we talk about construction and repair, then we should remember the screws that cannot be driven into wood except with a hammer, and it is generally impossible to unscrew them. Or wooden pegs driven into the wall. Or the fall of mezzanines and chandeliers. All these problems were solved with the invention of the anchor bolt.

Application of anchor bolts

As soon as they came into use, they were widely used in construction and operational installation. They are especially good for fastening to concrete. And the harder and denser the concrete, the more securely the anchors hold. In addition to concrete structures, anchor bolts, the dimensions of which are increased in width, are used for all types of block or brick masonry. The main task of anchors is to firmly fix both the structure itself and the hanging elements and equipment.

Anchor bolts for concrete, the dimensions of which are specially selected, are used to attach structural parts made of wood and metal to concrete. The length and width of the bolts must be selected taking into account both the part to be attached and the thickness. The installation technology itself is very simple. When the appropriate anchor bolt is selected, a hole is made in the wall using a hammer drill. Then you need to insert it and tighten the clamping nut until it stops.

Types of anchors

An indicator of high reliability is precisely the huge assortment that distinguishes anchor bolts. The dimensions, shape, design, and functionality of these products make them indispensable for fastening work for any type of material. There are two main types - anchor with nut and anchor with bolt. The following anchors are used for fastening metal and wooden structures: single- and double-expansion with a nut; 4-segment expansion; driven and with impact thrust. It is easier to hang technological or household equipment on a simple or 4-segment anchor hook. The same 4-segment and simple anchors, but with a ring, will help you tighten electrical and telephone cables.

Product design

Anchor bolts for concrete have different sizes, but they all have the same design. And since we are talking about the expansion principle of the product, the main structural element is the expansion housing (sleeve). The second most important part is the internal expansion nut for the anchor with the bolt. For a product with a nut, this will be an expansion cone on a stud. The ring anchor and hook anchor have the design of a part with a nut, simply the outer side of the stud is elongated and bent. Despite the fact that to prevent moisture from getting inside the product, the design provides a polymer sealing gasket.

Classifying anchor bolts, GOST divided them into three main groups:

common use;
frame;
reinforced.

So when purchasing, you should at least inquire about the country of origin; in China they hardly use carbon steel.

Anchor bolt sizes

First of all, when choosing the size of the anchor, remember that it is better to be safe than to later collect fragments of the air conditioner or buy a new boiler. Buy anchor bolts that are slightly larger than you expect. Usually on standard products the parameters are marked on the sleeve. If there are none, the outer diameter is measured with a caliper. In the number row 12x10x100 mm, the first digit indicates the diameter of the case. This means that the drill must be selected accordingly. The second number is the size of the bolt or stud, which will help you choose a key to clamp. The third number shows the total length. When choosing it, take into account the wall thickness. Anchor bolts have dimensions:

by outer diameter from 6 to 24 mm;
along the total length from 60 to 400 mm.

Finally, a few more words should be said about the benefits of an anchor bolt. Its price is not high at all, and the savings are huge. Depending on the design and size, the cost of a bolt ranges from 3 to 80 rubles per piece. Previously, before the advent of anchors, it was necessary to provide metal embedded parts for welding at the joints and installation of attachments at the design level. And the point is not in the cost of the hardware, but in the fact that all the calculations were done by a specialist, necessarily with a higher education, or even a whole department of such people with a corresponding salary.

An anchor bolt is a special type of fastener that is necessary to solve problems of fastening and fixing complex and heavy structures, prefabricated consoles, various suspended structures and building partitions. In this article we will analyze in detail the types, types, description, scope and technology of using anchor bolts.

1

The production of anchor bolts is carried out in accordance with the rules of GOST 24379-2012 from high-alloy and high-strength steels of various types. Thus, an anchor bolt is a metal rod of various lengths (from 45 to 225 millimeters) with a fastening end and thread. A feature of any type of anchor is the presence of a sleeve and a conical nut, on which the principle of anchoring is based.

When the fastener is screwed into a concrete or other base, the coupling deforms, which creates a powerful connection, so that it is possible to pull the bolt out of the base only with part of the base.

In addition to the types and sizes of anchor bolts, they are also usually distinguished by the method of fastening, which, in turn, is determined by the design and nature of the load. Standard types of anchors are usually classified as follows:

by the method of introducing the part into the base (screw, drilling, driving, etc.);
according to the methods of sealing possibilities at the fastening point (with expansion, with expansion, with a tube);
according to the design features of the anchor itself (cylindrical, solid, prefabricated, rod, etc.)

Classification of anchors

In addition to the presented classification, anchors are also usually divided into temporary and permanent, which also depends on the structural features of the part.

As a rule, reliable connection and retention of an anchor bolt in a particular building material occurs through friction and the creation of a stop. If chemical anchor bolts (based on hardening resins) were used, retention also occurs by internal gluing of the material. An important technical characteristic of anchors is the “pull-out indicator”. This value is measured in kilonewtons (kN), and according to the basic technical conditions and GOST requirements, its indicators should not be less than 10.5 kilonewtons. Thus, anchor pullout occurs if the bolt is installed too close to the edge of the base or if the conical nut comes out.

When designing and using different types of anchor bolts, characteristics such as bending and torque should also be taken into account. In the first case, the torque value is allowed from 5.2 to 25 Nm. The torque should be in the range of 10–40 Nm. The lower the permissible bending and torsional moment, the higher the strength of the bolt and the reliability of its connection to the base material. If the object of application has any special properties or design that requires the use of non-standard types of anchors, then custom production is allowed with the adjustment of certain technical conditions in accordance with SNiP 2.09.03.

2

Anchor bolts of various types are used primarily for fastening structures with a large mass and the presence of moving elements. In addition, foundation anchor bolts are also used for fastening parts with high tensile loads and for fixing various structures to concrete foundations. Thus, we can distinguish several areas for using anchors:

to create the reliability of fences, consoles, railings, stairs, balconies, etc.;
for connecting and fixing various equipment to foundation slabs, natural stone, brick, etc.;
for fastening various mechanisms and suspension systems, such as construction beams, split systems, etc.

Based on the types and types of anchor bolts, they are usually divided into two main directions - mechanical and chemical. Next, we will consider in detail and describe the main and most common types of mechanical anchor bolts.

Types of anchor bolts

A universal type of fastener that is used for connecting and hanging various suspended structures and blocks, during the operation of which they may need to be temporarily removed from the wall. The minimum permissible length of such a part is 60 mm, with a minimum diameter of 6 mm. A special feature of this fastener is the presence of a special hook as an extension of the screw. This design ensures that the nut becomes a clamp, and clamping and fixation occurs by rotating the hook inside the element.

Impact anchor bolt. One of the most common types of anchor fasteners, which does not have a nut or head. The principle of operation is based on the wedging of the tube and rod, which occurs from dense hammer blows. An impact anchor is used only for working with concrete foundations, but it is not capable of withstanding high loads and is mainly used for fixing various elements in walls, on the floor or ceiling.

Anchor bolt with countersunk head. The product consists of three parts and is designed for installation in concrete, natural stone or hollow brick. The fastening action is carried out according to the principle of expansion in the main element. As with most anchor bolts, there are minimum requirements for diameter and length.

Double-expansion anchor bolt. A type of fastening element, in which the connection is made by friction of the base and the lower conical element, which is a sleeve, bushing or a special spring ring. The anchor bolt is able to withstand high loads due to the fact that it is 2-spacer, and therefore is used for fastening structures with large weight to the foundation or load-bearing walls. In the case of double-expansion anchors, two sleeves or two spring rings are used for greater reliability of connection with concrete or other durable material.

Anchor bolt with hexagonal head. Another type of popular anchor, which has a hex head located on the bolt. Securing occurs due to the friction of the cone nut, which is located at the bottom of the fastener. The operating principle is similar for anchors with heads for a Phillips screwdriver.

Frame type anchor bolt. A lightweight version of fasteners, which is used for fastening structures made of plastic or wood. The main feature is the non-standard shape of the head, which can be aligned with the surface of the base.

Anchor bolt (stud) for concrete. Anchoring part with two fastening ends. It is tightened using a standard nut and is intended for fastening to partitions and walls of various massive structures, such as supporting consoles, hanging antennas, etc.

Another type of fastener is chemical type anchor bolts. This is an improved and most reliable option for anchoring, since in addition to the frictional force and the main stop, they also have a special chemical base that ensures reliable bonding inside the base. Among the advantages of this type of fastener are:

possibility of use for both external and internal work;
maximum resistance to various types of vibration;
maximum efficiency when working with loose or thin walls, as well as with fragile building materials, such as gas blocks.

In addition to the types listed above, there are several more options for anchor bolts for foundations and other types of structures that are less common during the construction process. Among such parts one can single out a metal anchor bolt for facade work, as well as floor, ceiling, plastic, ground or spring anchors, which have a fairly narrow area of use.

3

Fastening a standard type is a simple task that even a beginner in construction can cope with. Before starting installation, you must carefully drill a hole for the countersunk anchor bolt. In this case, it is necessary to select a drill or drill in such a way that its diameter and height completely coincide with the indicators of the anchor.

Anchor manufacturers, as a rule, take into account the dimensions of standard drills and produce products in accordance with these indicators. If you do not calculate the length, the anchor will have to be pulled out, and doing this manually, even if it is not fully tightened, is quite difficult.

Installation of anchors

An anchor bolt must be inserted into the finished hole. It is recommended to first remove dust from the hole using a construction vacuum cleaner or other devices. Remember that the anchor should not fit into the hole too freely; the most ideal option is to gradually insert the bolt using gentle hammer blows.

After this, tighten the nut until it stops so that the conical rod gradually wedges inside the concrete base. Next, the nut is unscrewed again, the necessary equipment or structure is screwed onto the stud, after which the nut should be tightened as tightly as possible with a wrench. If you use a chemical anchor, then simply insert it into a concrete or other base, having also first drilled a hole in it and cleared it of dust, and then insert the pin into the anchor.

To reliably fix various household and industrial elements, new high-quality fasteners are being invented. One of these powerful fasteners is an anchor bolt with a nut. Today we will tell you what its technical capabilities, operating rules and methods of application actually are.

How does an anchor fastener with a nut work?

Taking into account the fact that this fastening mechanism must hold quite heavy elements, it was carefully thought out and redesigned. The main structural element in it is a spacer pin, which has a cone shape at one end, and a metric thread is cut at the other end, onto which a nut is screwed. The entire length of the stud, except for the threaded part, is fitted with a special metal sleeve with slots.

This device works on the principle of “expansion”, that is, when we start to tighten the nut, the cone-shaped end enters the sleeve and expands it in the hole. A distinctive feature is that such an anchor has a cast pin, which is much stronger than other anchor structures. Well, and, of course, we forgot to mention the nut and, without fail, the lock washer, which are screwed on from the thread side. The washer does not allow the nut to go deeper into the hole when tightening.

In some cases, during fastening, installers use a second washer as an additional lock, which closes the hole at the installation site, but this approach depends on the specific installation conditions. The scope of application of such fasteners can be quite different: from the installation of stair railings to heavy metal structures. The most popular application today is the installation of brackets for air conditioning. The device itself has quite a decent weight, so the use of such a mount is completely justified.

Anchor bolt with nut - weight, dimensions: what does GOST tell us?

Since all fasteners are complex installation products, they all have appropriate technical documentation. It is from such documents that we can find out technical parameters if necessary. For example, when choosing this or that fastener, we want to know whether the anchor fastening will withstand a weight of 100 kilograms or not. Thanks to the fact that there is documentation, we will receive an answer to our question.

The smallest anchor, whose dimensions are 5x6.5x18 mm, according to the manufacturer's stated characteristics, is capable of withstanding a pullout load of up to 800 kgf. To make it clearer, kgf is the designation of kilogram/force, where the calculation takes into account the mass of one kilogram and the force with which this kilogram exerts pressure on the scale. Further calculations are quite simple, 1 kgf is equal to approximately one kilogram of any object, based on this, such an anchor will support a product weighing 800 kilograms.

Also, absolutely any bolt has a corresponding GOST, which divides all fastening structures into varieties according to their ability to withstand a certain load, the size and diameter of the fastening element. On large construction sites, such documentation helps in the selection of fastening elements and the purchase of appropriate materials.

Technical characteristics of anchor bolts

Technical documentation recommends installing such fastenings in solid solid materials, such as concrete, solid brick, natural stone. In each individual case, we must choose a bolt and nut whose dimensions will provide us with high-quality fastening. But it is worth remembering that during installation, when tightening the nut, the stud moves forward a certain distance; as a result, sometimes this length creates an obstacle when installing the products that we are fastening.

Today in stores you can find fasteners of almost any length, for various types of tasks. As a rule, the line of anchor fastenings begins with a stud size of 18 millimeters. The longest fastener reaches 400 millimeters in net size of the fastening pin. Accordingly, depending on the length, we also have different diameters; this value is calculated by the diameter of the sleeve for which the hole is drilled.

The diameter of the bushing usually starts from 6.5 millimeters, this is, as a rule, the smallest anchor; gradually, as the length increases, the diametrical value also increases; on the longest fastening, the bushing can be 20 millimeters in circumference, and such fasteners can withstand quite significant loads. If you are interested in the holding force of such fasteners, you can find it out from the technical documentation, we talked about it earlier.

When choosing an anchor, always consider the thickness of the surface on which the installation will be made. Long does not mean durable, and besides, you risk getting a through hole, which is undesirable when installing the fastener.

Reinforced version - double-spacer fastener

Due to the fact that consumer requirements are constantly growing, and there is a need for the installation of fairly heavy structures, it was decided to slightly modify the fasteners. This is how a modified product appeared on the building materials market - an anchor bolt with a double-spacer nut. This technology has made it possible to sufficiently increase the holding force of such fastenings.

The design itself is the same pin, but in this case two bushings are used as a holding mechanism, one of which is wedge-shaped and fits into the second bushing. Thus, by tightening the nut, we increase the holding properties, evenly distributing the force along the entire length of the fastener. It uses the same technology in its design, and, as practice shows, quite successfully.

This modified fastening is used mainly in production, but not only in the construction environment. For example, very often this mounting element is used to fasten machine tools in workshops. Usually, during operation, the machine creates a certain vibration, which, as a rule, is not needed, and if previously the machine was simply attached to the floor using concrete, today the easiest way is to use a universal mount and get rid of unwanted vibration during operation.

Correct installation and high-quality fastening

Do not forget that the correct installation determines, first of all, how the mount will work in the future and how much weight it can withstand. Basically, construction anchor bolts with nuts are installed according to the same principle, but according to certain rules, which we will now consider.

In various construction works, it is necessary to constantly attach any structures and materials to load-bearing surfaces - the ceiling, walls, facade and even the ground. But if for installation on plywood or a clay brick wall you can use a regular nail, then when working with concrete or sand-lime brick you will need a more powerful fastener - an anchor, the methods and places of fastening of which we will talk about today.

The actual fastening of something to something is provided mainly by friction forces. The hardware is immersed in the base material and upon contact with it, the same friction occurs that holds both the fastener itself and the attached element. Obviously, the friction force is determined by the characteristics of the material.

On the other hand, the fastener is subject to a pull-out load, as well as a bending load, torsion, and so on, and if the frictional force is less than the pull-out load, the fastener will be destroyed, which is usually observed when installing heavy objects and structures. An anchor is a device that can significantly increase the friction force, as well as create additional factors for retention.

This video will tell you how the anchor works:

Product concept

How does this happen? If you compare regular and threaded, it turns out that the second hardware provides much better fastening due to an increase in the working surface. The anchor is the next step in this direction.

Any of its designs implies the presence of an element that is wedged in the body of the material. That is, when immersed in the surface material, the anchor does not differ in function from a nail, but as soon as any load is applied to it - impact, tearing, bending, twisting, the working part of the anchor already located in the material becomes wedged and creates additional emphasis. This connection is so strong that fasteners are used when installing the heaviest structures - from massive household appliances to industrial chimneys and building frames.

However, this is not the only feature of the anchor. The heavy attached structure creates a large load. In the normal case, this force acts on the fastener, which leads to pullout. The anchor, due to its structure, transfers most of the load to the base material, thereby significantly increasing the strength and reliability of the fastening.

There is also a limitation here: a large load can only be transferred to durable, and, most importantly, dense material. Therefore, anchors are used when working with concrete, and are not used when attaching to, or. It is worth noting that special and quite effective anchors are produced for such materials, since the issue of fastening still remains open.

Advantages and disadvantages

An anchor is a specialized fastener. Of course, you can fix the lamp into a wooden wall with its help. But this will not be economically profitable, since the cost of the products is very significant, so the use of fasteners is only advisable in its own area. The product fully corresponds to its purpose.

The advantages of fasteners are undoubted:

very high load-bearing capacity, noticeably higher than that of other types of hardware;
variety of designs and sizes - you can choose the best option for fastening any material or structure;
The fasteners are made from the strongest steels, resistant to any type of corrosion, so this is not only reliable, but also durable hardware. According to its characteristics, it is designed for the same service life as load-bearing surfaces or structures;
installation, although it has its own characteristics, is quite simple and ensures minimal repair or construction time;
anchors can always be used to strengthen an existing structure, and the latter does not need to be dismantled for this;
Most anchors are resistant not only to static but also to dynamic loads, especially vibration.

The disadvantages are related to the design features:

in most cases, anchors are expensive;
most models require greater depth and large hole diameter;
fasteners are not universal. The anchor is used for fastening to dense concrete and solid brick, brick wall. There are special models for porous concrete.

The main difference between an anchor and other types of hardware is its high load-bearing capacity. According to the principle of operation - retention due to friction forces and additional volume, it is similar to a dowel. But the latter is designed for medium loads, is usually made of plastic and, in fact, is not an independent fastener, but acts only as a spacer part.

About whether an anchor is produced for fastening a door frame, brackets, braces, timber, floor slabs, aerated concrete, toilet or bathtub to a wall, fastening joists to a concrete floor, as well as other uses of anchors.

Types of such hardware

The specificity of different materials of products requires special fasteners, so there are a lot of varieties of products. They differ markedly in design, scope of application, and cost.

All anchors are divided into mechanical and chemical:

mechanical– fastening is realized due to friction forces and the shape of the thrust;
– the adhesive force acts here. This group is much smaller because the chemical method requires more time and depends on temperature: the glue or cement mortar must set. In addition, installation with their help is not nearly as convenient.

This video will tell you about the installation of different types of anchors:

By design features

The most informative classification is division by design features.

– anchor bolt or stud anchor. This is a metal rod, one end of which is made in the form of a cone. A spacer sleeve is placed on the cone. On the other side there is a thread. As a rule, the anchor is supplied with a washer and nut, although there is an exception: the ceiling wedge anchor has only a locking head. The fastener is placed in a pre-drilled hole and tightened with a wrench. In this case, the sleeve slides onto the cone and wedges, increasing in volume. The wedge anchor can withstand the heaviest loads, but also creates high stress in the material in the contact area. It cannot be used in loose porous concrete. Reduces the load of a model with two spacer sleeves.
Bushing– the spacer sleeve has the same length as the metal rod. The latter has a wedge-shaped head. When tightened, the nut moves along the rod and pushes the sleeve apart. Such fasteners create less stress in the material, so they can be used on both clay and solid bricks. Installation requirements are small, through installation is possible. However, the load-bearing capacity of fasteners is lower than that of wedge fasteners, so it is less common.
Expanding– an improved version of the bushing, more complex structure. The 3-4 leaf sleeve is expanded by a special spring and an expansion nut. The fastening is thus formed both by friction and by shape. The fastener has the same load-bearing capacity as a wedge anchor, but does not create stress in the area of contact with the material. It is used for installation on dense, lightweight, and cellular concrete and hollow brick. An expanding anchor is an expensive product, so it is used mainly by professionals.
– the inner surface of the threaded sleeve has a conical shape and cuts. He finds a wedge inside. When struck with a hammer, the wedge moves inside the sleeve and expands it. The drive-in anchor is designed to work with concrete and solid brick. Its installation is very simple and takes a minimum of time, however, the load on the material is even greater than that of a wedge one.

The exception is special fasteners, such as “Zikon”. Here, when the anchor is driven in, the sleeve slides onto the wedge and becomes wedged. The hole itself must be of a special shape - with expansion into the depth of the material, which is only possible when using a special drill.

Special– this category includes atypical products with a narrow specialization, for example: self-screwing, frame anchors with a nylon sleeve, fasteners for geogrids, special fasteners for hollow structures, and so on.

Fastening a pipe with an anchor (photo)

By area of application

Another classification is related to the area of application of the product. Anchors, as is clear from their design, are not universal.

For work on concrete walls– almost all types of anchors are designed for installation in dense, heavy material. The exception is harder to find.
Special fasteners for working with porous materials– for example, the same “Zikon” or an expanding anchor.
- a special design used when it is necessary to secure the frame or walls to the foundation. The fasteners are massive and difficult to install.
– option for remote installation. In this way, it is possible to fasten with anchors into durable materials through a layer of fragile thermal insulation material or decorative material.
– the anchor is designed for attaching suspended structures, ceiling systems, equipment and lighting fixtures to the ceiling.
– modification for securing a structure or structure to the ground. Can replace the foundation.
Frame– closest to the dowels, they have a plastic spacer sleeve.

Fastener Specifications

Comparing anchors of different structures with each other is a thankless task. Depending on the device and material, the indicators will be completely different. But since high strength and load-bearing capacity are associated with greater cost, there is a certain combination of price and product capabilities. And this allows you to select the optimal fasteners not only in terms of technical parameters, but also in terms of cost.

The size range of products depends on the purpose. Of course, the ceiling model will always have more modest dimensions and a smaller range compared to foundation bolts. But in general, the relatively large length is a common design feature - otherwise it is difficult to form a reliable mount.

When choosing products, the consumer is most interested in the maximum and working load. The latter is 25–30% of the maximum. It is worth considering that the load-bearing capacity is also influenced by the base material. Indicators are usually given for compressed concrete with a density of less than 1800 kg / cubic m.

Klinova

Wedge anchor - basic design, galvanized steel:

sizes vary from 6*40 to 12*120 mm, however, the size range may not be the same for different manufacturers;
the maximum thickness of the attached material ranges from 5 to 20 mm;
the minimum thickness of the bearing surface should be from 53 to 120 mm;
and, finally, the main parameter, the minimum pulling force - from 1.4 to 6 kN.

Its special variety, the ceiling wedge anchor, is not much inferior to the main models: the maximum material thickness is 5–8 mm, the pulling force is from 3.6 to 5 kN with a maximum product size of 6 * 60 mm.

Bushing

Sleeve anchor:

sizes range from 8/15*65 mm to 12/50*115 mm;
maximum thickness of fastened elements – from 15 to 50 mm;
ultimate bending moment – from 5.2 to 25 Nm;
pullout load – from 10.5 to 18.3 kN.

Spacer

Expansion anchor – data for one of the modifications is given:

dimensions - the total length of the product varies from 98 to 235 mm;
the thickness of the attached elements ranges from 20 to 60 mm;
minimum thickness of the base material – from 120 to 300 mm;
pullout load in the compressed zone of concrete – from 11.2 to 44.1 kN;
pullout load in the tensile zone of concrete (light materials) – from 4.8 to 31.5 kN.

Driver

Drive-in anchor - characteristics are given for one of the models. Material of manufacture – galvanized steel:

dimensions - length varies from 25 to 50 mm;
the thickness of the attached part is not standardized, since it does not depend on the anchor part;
minimum base thickness – from 100 to 130 mm;
pullout load in the compressed zone – from 3.9 to 12.6 kN. The minimum load in the compressed concrete zone is the same.

Now let’s find out what set of materials is needed to make an anchor fastening, and what is the composition of the metal elements.

Product materials

Anchors are designed to hold heavy materials and structures, and therefore are mostly made from durable steel grades. However, there are exceptions.

Steel - more precisely, high-quality structural steel, low-carbon, alloyed, cold worked. This material is as durable and reliable as possible. Carbon steel for cold heading and structural automatic steel are also used. The choice of strength class is determined by the purpose of the fastener: the higher the expected loads, the higher the strength class.
Stainless steel – or corrosion resistant. The alloy not only has the highest strength characteristics, but is also not subject to corrosion. Such fasteners are used in the most critical areas.
Non-ferrous metals - the most famous are brass and zinc-aluminum alloys. The material is rarely used, mainly for household work.
- special types of products may include plastic - polyamide, sleeve and steel rod. Another option is fiberglass, which is not much inferior in strength to metals.

Since anchors are designed for a long service life, their corrosion resistance is worth talking about separately. Stainless steel is not subject to rust. Other types of alloys are protected by coating.

Galvanic galvanizing - by electrolysis;
Chromating – galvanizing followed by treatment with a solution of chromic acid in order to obtain a film of zinc chromates;
Hot-dip galvanizing - immersing the product in molten zinc.

Complex fasteners consisting of several parts can be made of different materials. Steel for different parts is selected based on the expected load. For example, a composite wedge anchor from Fisher is designed like this: the sleeve and body are made of free-cut steel, and the bolt is made of alloy grade 10.9.

Anchoring is the most durable and reliable fastening, as it ensures retention due to at least 2 factors - friction force and shape. Anchors are indispensable in all cases where installation is required, from really heavy equipment and structures to household appliances.

This video contains useful tricks for installing anchors: