Regular or blind rivets. Device of blind rivets

How to choose rivets

Despite the fact that the technology of blind rivets has greatly simplified the creation of a riveted connection, there are certain points that should be paid attention to, because if installed incorrectly, even the highest quality rivets will not be able to provide a reliable connection of materials.

Things to think about during the preparatory phase:

Rivet Connection Configuration

Before purchasing rivets, determine what values ​​of shear and tensile force are required for a single rivet connection of the designed assembly. It is these characteristics that determine the strength of the entire riveted connection, and it is from them that one must start when calculating the interval between rivets, in choosing the material and diameter of the rivets. Then use the manufacturer's catalog to determine the key characteristics of the rivets that will best suit your project.

Thickness of the rivet joint package.

Blind rivets have another important characteristic - the thickness of the package. This value shows the range (minimum and maximum thickness of the materials being joined) within which a rivet of a certain length will provide a reliable connection. To select rivets for your project, be sure to measure the total thickness of the materials being joined. Do not base your choice on the length of the rivet! The characteristics of rivets from different suppliers may differ and, with the same length, may have a different operating range. Having found out the thickness of the materials to be joined, you can easily select a rivet of the appropriate size in the manufacturer’s catalog - it is important that the value of the total thickness of the materials to be joined is within the range indicated in the “package thickness” column. Remember, an insufficient rivet length will not allow the formation of a full-fledged reverse head, and an excessive length will lead to its excessive deformation - both options are unacceptable, since they do not guarantee a reliable connection of the parts.

Selection of blind rivet material

Size and type of rivet hole

The size of the rivet hole has a great influence on the quality of the entire connection. A hole that is too small will complicate the installation of rivets and may result in a poor-quality rivet joint. A hole that is too large will weaken the shear and tensile properties of the rivets. As a rule, when creating such a connection, the rivet will be deformed not on the back surface of the materials being joined, but directly inside the joint, which will lead to swelling and delamination of the materials being joined. To get the best result, we recommend that you check the diameter of the hole for your rivet in the manufacturer’s catalog. If it is necessary to obtain a smooth joint surface, use a countersunk rivet. To do this, the hole must be processed with a countersink for the countersunk head of the rivet. The rivet is installed flush with the surface of the materials being joined, forming a flat surface at the junction. Before installing the rivet, clean the holes thoroughly - chips and burrs around and inside the hole are unacceptable.

Access to the rivet installation site.

As you work on your project, keep in mind that in order to install the rivet, you need to provide access for the rivet tool. When planning places for installing rivets, it is necessary to avoid corners, narrow channels and other places that make it difficult for the riveting tool to reach. If such situations cannot be avoided, special tools for installing blind rivets in hard-to-reach places will come to the rescue. In addition, almost every serious manufacturer of riveting equipment has special equipment for such cases. Typically, this accessory is compatible with standard tools and can be purchased separately.

Now that the preparatory part of the work is completed and we have decided on the choice of rivet, we will consider several situations that may arise during the installation of the rivet.

	1. Connecting parts of different thicknesses. If it is necessary to fasten a thin part to a thicker one, try to install the rivets on the side of the thinner material, so that the reverse head is formed on the side of the thicker, and therefore more durable, part. If this is not possible, place a washer of the appropriate diameter on the side of the thinner material - this will protect the surface from deformation and allow you to create a more durable connection.
	2. Connection of soft and hard materials. In the case of fastening a part made of soft material to a harder surface, it is best to use a blind rivet with an enlarged shoulder, and the reverse head should be formed on the side of the harder material. If this is not possible, place a washer of the appropriate diameter on the soft material side - this will create a more reliable connection. In addition, expansion and flap rivets are available for joining soft materials.
	3. Connection of fragile parts and plastic parts. For connecting fragile parts, plastic, expansion and leaf rivets are best suited. In cases where the plastic parts being connected have sufficient strength, the use of standard blind rivets is quite acceptable.
	4. Rivet head. The shape of the rivet head is selected depending on the requirements for the joint surface. If protrusion on the face of the joint is not acceptable, a countersunk rivet must be used - this type of rivet installs flush and provides a smooth surface at the joint. There are also special rivets for obtaining a countersunk head on both sides of the connection.
	5. Sealed connection. To create a dust- and waterproof connection, closed-type blind rivets are used, or, as they are also called, “blind” blind rivets. This type of rivet completely “seals” the hole, preventing dust, moisture and fumes from entering the joint.
	6. Strong connection. Since quite a lot of force is required to install the rivet, connection A in the image cannot be considered satisfactory. Connections B and C are a more suitable way to solve the same problem. To create a stronger connection, use high-strength or reinforced rivets.
	7. Tool access. When making connections in hard-to-reach places, make sure that there is a gap around the rivet installation site that is necessary for the riveter to fully work. If you cannot get to the installation site, try installing the rivet from the reverse side. In addition, manufacturers of riveting equipment offer a variety of additional equipment for installing rivets in hard-to-reach places.
	8. Distance from edge. To obtain a riveted connection that is optimal in terms of strength, it should be remembered that the distance from the rivet axis to the edge of the material being joined should not be less than two rivet diameters. In nodes where the strength of the connection is not of great importance, the distance to the edge of the material may be less.
	9. Axial clearance on the reverse side of the working surface. The axial clearance is the distance from the shoulder of the rivet to the head of its shank minus the thickness of the materials being joined. When designing a connection, it is necessary to provide the axial clearance necessary for the correct formation of the return head.
	10. Working with soft and loose materials. Because soft materials tend to compress, they generally cannot provide the rigidity required to install a threaded connection. In this case, it is recommended to use special bushings for installing blind rivets as additional support.

Nowadays, to fix two or more riveted elements, it is customary to use blind rivets, which quickly replaced traditional rivets for metal due to ease of installation and excellent performance properties. Today, these devices are widely used in construction, shipbuilding and ship repair, mechanical engineering, in the installation of safety equipment, in the textile industry and many other areas of human activity. The solution allows you to achieve the most durable connection, however, if the task is to fasten heavy-duty parts, then it is customary to use threaded products.

What materials are rivets made from?

A variety of materials are used to make blind rivets. This feature significantly expands the scope of their application, allowing the product to be used in almost all types of work. In addition, the rivet itself can be painted in any color, which is necessary for light industry (textile), where special emphasis is placed on the color of the fixing element.

When choosing materials for the production of rivets, the material of the part being fastened is taken into account, as well as the characteristics of the environment where the fastened structure will be used. In most cases, the following materials are used for such purposes:

1. Aluminum. The use of pure metal and its varieties: anodized or varnished is supported.
2. Cink Steel. It is characterized by increased strength and many other advantages.
3. Stainless steels. A2 has maximum resistance to rust, and A4 is coated with a reliable anti-corrosion layer and is able to withstand an acidic environment. Most often it is used in the chemical industry. Imported analogues, such as DIN 7337, are also popular. Stainless steel is considered the most popular and widespread material with excellent performance properties and increased strength.
4. Copper.
5. Copper-nickel alloy (Monel). It is composed of 70 percent nickel and 30 percent copper.
6. Polamid. It cannot boast of too high strength, so it is most often used in the production of clothing items and textile products.

Regardless of the materials used to produce rivets, they undergo special certification and are also confirmed by the GOST standard.

If you are faced with the question of choosing a material for the manufacture of fasteners, you must take a responsible approach to the selection of materials for hardware with fastened parts, which is associated with a high risk of fastening failure. In most cases this happens due to appearance of a galvanic couple hardware - part. If the ambient humidity is high enough, which can be explained by wetness, the galvanic couple becomes a conductor of electric current, which contributes to the destruction of the fastening.

For example, contact of aluminum with steel leads to very rapid oxidation and destruction of aluminum. For this reason, it is customary to use stainless steel rivets of domestic or foreign production to fasten steel parts. Steel rivets are very popular due to their strength properties. But galvanized steel solutions are not very popular. This is due to the fact that zinc coating cannot boast of a long service life, so it wears out very quickly. The problem progresses in a special way when using moving elements.

A fastener made of a copper alloy is considered a universal hardware. The only “enemy” of copper is aluminum, while other metal blanks practically do not conflict with metal.

The disadvantages of such solutions:

1. High price.
2. The appearance of an unsightly color after the oxidation process starts (after a certain period of time, a green coating appears, which is the remains of oxidized copper). True, such formations do not in any way affect the strength of the product.

The most universal fastening compound is polyamide. Such a rivet reliably protects almost everything you can imagine, although it is not particularly strong.

If you need to order rivets, be sure to pay attention to the material from which it is made specific model.

What are the design features of blind rivets?

Aluminum (all sizes are available on almost any website of the relevant store) rivets have always been in special demand. True, due to their low strength, they are not recommended for fastening heavy structures and those products that are constantly under heavy loads or aggressive environmental influences.

It is no secret that the basic elements of exhaust hardware are the body and the rod. The body is a body, bushing or cylinder. It is this part that plays the role of the main fastening element, which performs the load-bearing function. The body includes a “side” head, as well as a hollow cylinder. Sealed hardware has a tightly sealed end.

Based on the type of head, hardware is distinguished with:

1. High side.
2. Wide side.
3. Hidden side.

Wide and high options provide the most durable riveted fastening. Such fixing elements are noticeable from the outside and are capable of forming characteristic “bulges” on the surface of the workpiece. As for the hidden side, it can provide an almost smooth surface at the attachment point, although reliability is significantly deteriorated. The thickness of the hidden side is about 1 millimeter, and the main massive part of the head is fixed in the mounting hole.

The thickness and length of the rivet cylinder varies. It is the outer diameter of the cylinder that determines the diameter of the hardware in the order name. The dimensions of the cylinder play a very important role among all other dimensions. These are the ones you should pay special attention to when purchasing these fasteners.

The main purpose of the fastening is to provide a movable or fixed connection of several parts or elements.

In most cases, the dimensions of a cylinder are indicated by two numbers separated by an “X”, where the first indicator determines the outer diameter, and the second determines the length.

The rod is an important structural unit

The next, very important structural element of a blind rivet is the rod. It acts as a rivet and can be made of strong steel, which is much stronger than the body. The end of the rod has a special head that acts as a rivet for the inserted end. When performing installation work, the rod is pulled out using a special pneumatic riveter, and if there are too many fasteners, you can get by with ordinary pliers. True, the latter case involves the use of a certain physical force.

The main advantage of the design of blind rivets is the possibility of one-sided installation, when access to the fastening is sufficient only from one side.

A more durable solution (threaded) has a characteristic thread inside the cylinder. A classic blind rivet does not have such a thread..

The threaded cylinder also has a screwed-in rod, which is not pulled out with force, but is carefully unscrewed. To strengthen the connection, a secure screw or bolt is placed inside. As a result, it is possible to create a kind of “closed” fastener, which is often called blind.

After determining the appropriate sizes and materials, as well as choosing the appropriate type of bead, you can begin to search for the specific type of rivet itself.

What kind of rivets are available in the market

Depending on the required characteristics that must be present in the fastener, the type of fastener is selected. Currently, several types of hardware are offered for sale:

1. Combined. Capable of providing reliable permanent connections to structures made of hard alloys or materials with increased strength. In addition, they are also used for fastening thin-sheet materials. Today, combined rivets are a very popular type of fastening elements, so they are often used for all kinds of installation work. The product provides the most durable fastening that can easily cope with even the most intense loads.
2. Sealed rivets. This solution is a highly specialized fastener option, which is especially in demand for the shipbuilding industry. The design feature of such fasteners is represented by a sealed end with a rod. Most often, such hardware is made of copper, however, for equipping civilian ships and boats, you can get by with aluminum rivets. As for fastenings in industrial production, stainless steel models remain relevant there.
3. Multi-clamp. Such products differ from all previous ones by the presence of several riveting sections. They can be used to fasten three or more structural elements for a movable connection. Between every two elements there is a riveted section. They are installed using a special device (in most cases using a blind rivet gun).
4. In addition, there are also reinforced models of hardware on sale. In essence, this is the same blind rivet, although its cylinder is made of thicker material. It is customary to use durable aluminum.

Today there are many other types of fasteners, which may differ in both the length and shape of the rod, but there is no point in dwelling on them, since the above solutions are quite universal and are quite suitable for most purposes.

Features of installing rivets

After purchasing a rivet, many people have a question: “How to properly install this fastener?” Fortunately, the design of the product remains very simple and understandable, so at the installation stage there are practically no difficulties or incomprehensible moments.

It is only important to acquire a special rivet tool, which will significantly reduce time costs and simplify the upcoming task. Nowadays, such tools are available in any building materials hypermarket, so purchasing them will not be something very difficult. In addition, both mechanical riveters and pneumatic riveters are offered for sale. You can also use an electric model. If you can’t buy a tool, you can use regular pliers.

The installation process itself is carried out in the following way. Using a drill, you need to drill a hole at the fastening point with a diameter 0.1 millimeters less than the diameter of the fastening connection. The depth of the hole is comparable to the length of the cylinder, minus the length of the riveting section. The fastening element is fixed into the hole with the rod toward itself, and then the rod is pulled out using a rivet tool. Ultimately, all elements are securely fixed.

Summing up

Blind rivets are indeed a very useful, reliable and high-quality connecting element, with which you can carry out a lot of installation work, achieving the most durable and good connection of all kinds of structures. Modern rivets meet all requirements and standards, so they prevent product deformation even under the most intense impacts. When choosing such a solution, it is important to set priorities correctly and give preference only to proven products. This will allow you to make a smart purchase and avoid mistakes.

Blind rivets are one of the ways to create a permanent connection of sheet materials up to 45 mm thick, and even with a through hole measuring 5 mm, which can then be used for any purpose. We’ll look at what you need to know about this fastener in this article.

1

This fastener has several other names - pull rivets or break rivets. After all, the fastening process usually looks like pulling, but ends with tearing off the rod on which the element was mounted. The rivet itself is hollow, which is why the inner hole can then be used. Often wires or some kind of fasteners are successfully placed in it. The proportions of the diameters of the head and body of the rivet are usually 1 to 2, but in some standard sizes it is 1 to 3. Initially, the beautiful head is only on one side, the second side rests on the thickened tip of the rod. With this narrow end it is threaded into the hole of the materials being fastened, then the rod begins to be pulled out.

Blind rivets

Its thickened end drives inside the rivet, expanding its body and forming a retaining head on the other side. Then the rod is broken off and the remains are taken out from inside the formed fastening, leaving a hole there. Although you don’t have to take them out if they do not interfere with the further use of the fastened object. Recently it can be seen more and more often, and there are many reasons for this. This is very convenient when we have access to the connection point only from one side, and installing such fasteners is very simple. The riveting tool itself is inexpensive and does not take up much space. During operation, you will not have to somehow fix the second end of the rivet before pulling it out. This in turn speeds up the process and increases productivity. Growing popularity is forcing manufacturers to work on diversifying their products.

Along with the usual ones, there are also special blind rivets. For example, waterproof or gas-resistant. They are called blind or sealed. Regardless of the type, these connecting elements are installed using a riveter, a special gun. It can be mechanical or pneumatic; naturally, in the second case, productivity increases significantly. Battery-electric models are also available.

2

It’s worth noting right away that you will have to choose two parameters – the material of the rod and the rivet itself. Obviously, in order for the rod to press the rivet without breaking, it must be stronger. This is achieved in two ways - either the materials for these two components are different, or the same, but of different technical strength. Let's look at examples and markings. Cheapest of all. But this is not pure metal, but an alloy with magnesium, denoted by the formula AMrX, where X is a number reflecting the percentage of magnesium in the material.

Aluminum blind rivets

If the rod is made of galvanized steel, then the rivet marking will be Al/St. If both elements are made of aluminum, then Al/Al.

But the rod in this case must have a higher magnesium content in its composition in order to be stronger than the rivet itself. When the rod is made of stainless steel, the marking is Al/A2. When the rod and rivet are made of stainless steel, you will see the markings A2/A2 or A4/A4. Obviously, here again the strength of the rod should be higher. When the material is galvanized steel, the marking is St/St. Exhaust parts can be made of copper. When the rod is galvanized steel, the code is Cu/St, if it is bronze – Cu/Br, if made of stainless steel – Cu/A2.

3

If there are few options for parts based on the strength of the material, then the sizes are more numerous, and a reference book will help you choose them correctly, which is easy to figure out yourself. There you will find four columns: rivet dimensions, thickness of the materials being joined (range of values), diameter of the side (head) and diameter of the hole (also range of values). Naturally, it is not recommended to approach or even cross the boundaries of the ranges.

Blind rivets of different sizes

Let's give an example. The thickness of the material being fastened is 16 mm, what size rivets are suitable for us? 3.0x20, 3.2x20, 4.0x20 and others. The first option is on the verge of possibilities in all respects. Why is there no confidence that the dimensions of this rivet will allow it to withstand not only the joining process itself, but also the subsequent operation of the product. Moreover, the smaller the first parameter, the smaller the head diameter, which can also be called a reliability factor. The third and subsequent options from the table already seem unnecessary, since the diameter of the rivet itself, and therefore the hole in it, will be very wide. This, of course, increases the width of the cap.

But all this will be unnecessary; the dimensions of the hole for threading the rivet will be very large. It is likely that in materials with a total thickness of 16 mm it will not be possible to make a large hole without much destruction. Therefore, the dimensions 3.2x20 seem optimal, since for a diameter of 3.2 mm the thickness of 1.6 cm is in the middle of the range covered by this size, all that remains is to choose the length, which is 20 mm, and you can start working. In special cases, it is worthwhile to carefully study the issues of material strength; data should be sought in reference books on metals.

Rivet elements

Regardless of the type, almost all blind rivets are designed the same.

A blind rivet is a fastener consisting of two parts: a hollow tube with a collar on one side and a tear-off all-metal rod. The hollow tube is called the body or sleeve of the rivet, and the part with the shoulder is called the head of the rivet. Usually the body of the rivet is round in cross-section. The diameter of the body determines the size of the rivet. The hole in the body of the rivet is usually through - it passes through the entire body. The rod (or core) protruding from the body of the rivet is the second, no less important part of the blind rivet. In appearance it resembles a nail, which, when installed, is pulled through the body of the rivet.

In general, according to the Russian standard GOST R ISO 14588-2005, this type of rivets is usually called “blind rivets”. However, the name “blind rivets” or “traction rivets” somehow caught on and became most widespread. There are many other “folk” names, here are some of them:

• Breakaway rivets
• Combination rivets
• Blind rivets
• Single-sided rivets
• Rivets with core
• Rivets

All these names are related to the blind rivet.

Installation of rivets

Installation of a blind rivet occurs as follows: the body of the rivet is inserted into the hole prepared in the parts to be joined. Then the jaws of a manual riveter or the riveting head of an automatic tool, resting against the shoulder of the rivet, grab the rod. As the tool pulls the rivet shank through the body, the head of the shank expands the rivet body to form a joint. The rod pulled out by the rivet tool deforms the tail of the rivet, forming a reverse head on the back surface of the materials being joined. At a certain moment, when the traction force of the tool reaches a given value, the rod breaks off in the separation zone and falls off. The rivet is installed and the reverse head (a part of the body formed during the installation process on the reverse side of the surface of the materials being joined) securely holds the entire connection.

Rivet elements

Let's consider the main elements and terms related to the installation of blind rivets:

Hole size.
The size of the rivet hole plays an important role in the reliability of the connection. It is important that the hole is not too large, but not too small. As a rule, each blind rivet supplier indicates in its catalog the recommended hole diameter for installing a particular rivet. This information can also be found on the original packaging. Try to avoid burrs in and around the hole.

Thickness of the package of materials to be joined.
The range of thickness of a package of joined materials is the minimum and maximum total thickness of the joined parts that can be qualitatively connected with a rivet of a given nominal length in a hole of a certain diameter. It is important that the thickness of the package of materials being joined is within the range recommended by the manufacturer. Data on the thickness range of the materials being connected for a particular rivet can also be clarified in the manufacturer’s catalog.

Shear force.
Shear force is the maximum load that a riveted connection can withstand without destruction, applied perpendicular to the rivet axis.

Breaking force.
Tensile strength is the maximum tensile load that a riveted joint can withstand without failure, applied along the axis of the rivet.

The shear and tensile force values ​​of the rivet are key characteristics. It is from them that one should start when calculating the strength of the entire riveted connection. Once you have determined these values ​​for one individual connection, use the manufacturer's catalog to determine the material and rivet diameter that will suit your application.

Choice of material.

Rivet head.

Based on the shape of the head, there are three main types of rivets:

Blind rivet with standard straight shoulder. This is the most common type of rivet and is suitable for most connections.

Blind rivet with hidden collar. This type of rivet is installed in a countersunk hole and is used to create a flat surface at the riveted joint.

Blind rivet with an enlarged collar. These rivets are used when a part of a thinner, softer or brittle material is connected to a hard surface. The increased head area evenly distributes the pressing force over the working surface of the materials being joined without causing their deformation.

Rivet tool

To install blind rivets, you need a special tool, which, fixing the body of the rivet, pulls the rod through it, thereby forming a reverse head. Currently, there are several types of rivet tools for working in various conditions.

In the vast world of fasteners, steel rivets occupy a special place, invented much earlier than threaded and, even more so, welded connections; they still adequately fulfill their purpose in various spheres of human activity.

In contact with

Alternative Fasteners

The products perform their main task - to fasten metal (and not only) parts - and always guarantee the reliability of the resulting structure.

They are durable, easy to install and resistant to chemicals. At the same time, they are compact and versatile. Today they are trusted by craftsmen in various fields: shipbuilding, aircraft construction and auto repair.

Rivets for plastic and metal are widely used in electrical engineering, in the manufacture of containers, and in the construction of bridges. Often used as an alternative, for example, in explosion and fire hazardous facilities. Only they can cope with fastening parts in places where access for other types of connections is limited.

Advantages and disadvantages

Why is this type of connection preferred, for the abundance of advantages or the minimum of disadvantages? Let's list those and others.

Advantages:

• compactness;
• durability;
• reliability;
• ability to work with various materials;
• low price;
• variety of sizes and materials;
• Possibility of color selection.

Compactness is undoubtedly convenient. The main competitor of the products is a bolted connection with its own set of nuts and washers - this is clearly not a priority.

Important! The service life of rivets, subject to the installation and operation rules, can be equal to the service life of the parts themselves in the connection.

The products are practical not only when connecting metal parts. Today they are widely used when working with plastic and in textile production. They look original in combination with wood and leather. The aesthetic component of the priority of this fastener is the ability to choose a color scheme. , varnishes or galvanic coating options - it’s up to the consumer’s taste.

Flaws:

• create a permanent connection;
• installation of certain types takes a lot of time;
• the vast majority are disposable;
• installation requires special tools and certain experience.

A riveted connection, by definition, does not require disassembly. Installation of almost all types cannot be considered fast. This applies to both retro hammer-type and more modern threaded ones.

Each stage of installing a connection (marking and riveting itself) is labor-intensive, although this can be sacrificed in the struggle for the quality of the connection.

The metals that go into the production of rivets, no matter how soft they are, remain metals. In this regard, the installation of these fasteners requires the use of specific tools: from a simple hammer and mandrel to complex ones, such as a riveter.

Types of fasteners

In nature, there are many types of fastening and the same variety of fastening elements.

We list the most popular of them:

• driving,
• exhaust threaded,
• exhaust smooth.

The classic and most ancient type of fastener is the driven-in type. The second and no less popular name is “under the hammer”. The material can be very different: aluminum, copper, steel. They consist of a cylindrical rod and a head (mostly, according to GOST 10299-80, this is a hemisphere). Semi-concealed, countersunk (GOST 10300-80) and cylindrical heads are also popular.

Important! The diameter of the rivets cannot be unlimited. Economic and technical feasibility determine their maximum length.

They are simple in shape, and simple auxiliary tools are used as installation assistants: a settler, a pretensioner and a hammer. In mass production, steel products are assembled with electric hammers or piston hammers.

When riveting by weight, you cannot do without reinforcement (anvil). During installation, a driven rivet requires compliance with tolerance standards for the diameter of the holes and the length of the rivet. Insufficient length will not allow the formation of an optimal head; excessive length will disrupt the tightness of the connection.

The design consists of two bushings connected at its head. The outer sleeve should be longer than the inner one and made of softer metal. The difference in the length of the bushings should be at least half the diameter of the hole in the parts being connected. In this area, a thread is cut, due to which the outer sleeve will be compressed and a second head will be formed.

Of all types, threaded rivets are the most expensive. However, the threaded rivet compensates for these shortcomings with quality, installation speed and neat appearance. The latter argument justifies their widespread use in the automotive industry and in the manufacture of various household appliances. The largest blind rivet has an internal thread M16, the smallest - M2.

Exhaust smooth is the most popular type of connection of parts for lightly loaded structures. Widely used in everyday life, in private farmsteads and in workshops. A worthy alternative to welding where available. The popularity of this type of fastener obliges us to dwell on them in more detail.

Design features

Classic blind rivets are a structure consisting of a cylindrical body with a head and a shank. During installation, pulling out the shank (core) promotes the formation of a second head on the back side. Thus, the parts are securely fixed to each other.

The diameters of the head, body and shank are regulated by the requirements of GOST 10299-80. The length of the shank is also standardized by the dimensions of the gripping mechanism of the riveter.

Modern types of blind rivets can be made from various materials.

Here is a list of the most popular body/shank combinations:

1. Steel (galvanized) / steel (galvanized);
2. Aluminium/steel (galvanized);
3. Aluminum/aluminium;
4. Aluminium/stainless steel;
5. Stainless steel/steel (galvanized);
6. Stainless steel/stainless steel;
7. Copper/steel (galvanized);
8. Copper/bronze;
9. Plastic/Plastic.

Ideally, the rivets and the parts being fastened should be made of the same metal. This will eliminate the formation of a galvanic process (accelerated destruction of a more active metal) and will extend the life of the metals of the fastened parts and the fastener itself.

The cylinder filling the hole can be either smooth or grooved. Small protrusions here imply crushing during installation (for example, from a light blow with a hammer) and thus allow a weak and tight tension.

The above-mentioned State Standard 10299-80 strictly regulates all dimensions (geometry) of exhaust aluminum products. This unification makes it possible to integrate the use of these connections into a system and simplify the calculations of most prefabricated structures.

When length matters

Let us repeat, pointing out the importance of such a parameter as length. The correct formation of the closing head and the tightness of the connection depend on it. Excessive length here will be just as harmful as its lack. Against this background, the task of calculating the optimal length of connecting elements is important.

S – total thickness of connected parts;

d – diameter;

L is the required length.

Example: we have two parts with a thickness of 10 and 15 mm. The calculated diameter of the rivets is 4 mm. According to the formula: L = S+1.2d we have - 10+15+1.2*4 = 26.8 mm.

In this formula, “1.2” is the correction factor.

Its value depends on:

• head shape;
• material;
• heat treatment.

For domestic use, we calculate the length of the rivets using a coefficient of 1.2. In this case, it can be accepted as average and optimal.

Table 1 will help you choose the closest standard size for diameter 4. We get 30 mm.

The science of “Strength of Materials” recommends placing blind rivets (and others) at a distance of no closer than five diameters from each other. Let us add that there are special formulas for calculating fasteners for shearing and crushing of heads. Such calculations are made when designing quite important structures, and they are practically not used in everyday life.

Installation

Let's look at the process of installing traction fasteners. There are two parts that need to be connected to each other. After simple calculations of the size and required quantity, and selection of the closest standard size, we carry out the process in a certain sequence.

Main stages:

• make surface markings;
• drill holes taking into account the allowance;
• remove possible burrs on both sides of the hole;
• install aluminum exhaust products into the hole with the shank facing you;
• We grab it with a riveter;
• tightly pressing the riveter support to the head, smoothly but forcefully squeeze the tool handles;
• We carefully cut off the remaining free part of the shank or break it off with wire cutters; the sawing option also has a right to exist here;
• If necessary, use a file to give the head a neat, finished look.

Despite its archaic origin, aluminum exhaust mounts continue to be in great demand today. This applies equally to industry, construction, and household use.

Useful video: features of screw and blind rivets

The variety in standard sizes and materials benefits their versatility, and accurate calculation of the geometry for each use is a guarantee of the reliability and durability of this mount. Do not neglect calculations, because mistakes can subsequently bring not only loss of time and psychological discomfort, but also result in more serious consequences.