What is a Rivet?

K category:

   Crane operators and slingers

Publication :

   Rivet connections

Read more:

   Welded joints

Rivet connections

In what structures are riveted joints used?

Riveted connections are used in those structures on machines that perceive strong vibration or large repeated impact loads, as well as in structures whose parts are made of non-weldable materials.

What is a taped seam?

Promotional offers based on your interests:

A rivet seam is a permanent connection of parts of a structure, machines or mechanisms using rivets.

How are rivet seams divided depending on the location of the connected units or parts?

Depending on the location of the parts and assemblies being connected, rivet seams are divided into lap seams, in which the edge of one sheet or assembly is overlapped with the edge of another, and butt seams, in which the parts to be connected are tightly accustomed to each other with their ends and are connected using one or two overlays

How are the rivets arranged in the rivet seams?

Rivets in rivet seams are arranged in one, two or more rows, therefore rivet seams are called single-row - if the rivets are located in one row; double-row - if the rivets are located along the seam in two rows and multi-row - if the rivets along the seam are located in several rows.

How are rivet seams classified according to purpose?
According to their purpose, rivet seams are divided into strong and dense (strong-tight), with strong rivet seams used to absorb external loads, and dense (strong-tight) to ensure tight joints in some boilers, vessels, etc.

What is a rivet?

A rivet is a metal rod with a round cross-section with a head at one end called a cap. The second head of the rivet is made during riveting and is called the closing head.

What material are rivets made from?

Rivets are made from carbon steel St. 2, Art. 3, 10KP, 20KP, etc., similar to them, and in structures that require alloy steel rivets, they are made from steel 09G2 or stainless steel X18N9T. In addition, for riveting parts made of non-ferrous metals and non-alloys, rivets of the MZ, L62, AD1, D18P brands are also used, also made of non-ferrous metals and alloys.

How are rivets distinguished by the shape of their heads?

Based on the shape of the heads, rivets with a semicircular head, rivets with a countersunk head and rivets with a semi-countersunk head are distinguished. The most widely used rivets are those with a semicircular head.

What are the known riveting methods?

Cold and hot riveting methods are known: Cold riveting is performed with rivets with a diameter of up to 10 mm without heating them.

Hot riveting is done using rivets with a diameter of more than 10 mm with heating of the rivets to a certain temperature.

A rivet seam can be made manually with a plumber's hammer, mechanized with pneumatic riveting hammers, and mechanically with stationary riveting machines.

Promotional offers:

Read more: Welded joints

Category : - Crane operators and slingers

→ Directory → Articles → Forum

Source: http://stroy-technics.ru/article/zaklepochnye-soedineniya

What are rivets made of?

The rivet can be made from almost any soft metal.

Even a nail can be turned into a soft rivet if you “release” it by throwing it into the fire, for example, into a grill. All that remains is to cut the rivet to the required length, the cap is already ready.

To make a rivet from aluminum, copper or annealed steel wire, you need to clamp it in a vice, leaving 2-5 millimeters above the jaws (depending on the size of the head you need) and hit the a light hammer. After this, cut the required length of the rivet based on the thickness of the parts to be joined plus the allowance for creating the head.

You also need to rivet the connected parts with a light hammer, alternating blows with a pointed and blunt end.

If you need a lot of rivets of the same size, you can make a device from two metal plates, bars or corners:

Clamp the workpieces in a vice and drill a hole in them of the required diameter and depth. For a countersunk head, flare the edge of the hole with a drill of a larger diameter. Insert pieces of wire prepared to the same length one by one into the hole and “create” a rivet. To remove the rivet, the halves of the device are connected.

The scope of use of such a fastening element as a rivet is so vast that it is impossible to remember a single technological industry where it is not used.

Traction rivets, for example, are used for fastening delicate materials, forming completely closed combinations, reliable connections, etc. such industries as: aviation, production of cabinet and upholstered furniture, boats and their repair, ventilation systems, construction, mechanical engineering and even children's playgrounds with attractions, it is impossible to imagine without rivets.

In this article we will talk about the main types of rivets, their technological characteristics, scope of application and fastening methods. Find out the features of blind, threaded, aluminum, steel, screw, nut, and stainless steel rivets.

What are open, closed, reinforced, petal, spacer, multi-clamp, terminal cassette and plastic rivets?

Rivets as a fastening element

They are created in order to facilitate work and reduce production costs. In addition, the rivet has a number of technological characteristics that make it irreplaceable and reliable. Let's look at the main types of rivets and their characteristics.

Blind rivets open

This rivet is of the standard type. Its body has a through hole, so it resembles a hollow rivet. The main difference from the hollow one is that after riveting, the head remains in the body of the rivet, as part of the return head.

The scope of application of this rivet is where there are no strict requirements for strength and reliability, the thickness of the materials varies, and the sizes of the holes vary slightly. These rivets are the most popular on the fastener market.

Blind rivets closed

This type of fastener is often used to connect materials that require increased tightness. The body of the rivet does not have a through hole, which in turn makes it possible to create a reversible head that seals the hole.

Based on this, such rivets have a second name - closed rivets. A tight connection prevents moisture, dust and dirt from penetrating inside. If you use additional gaskets, you can make the connection completely sealed.

Reinforced rivets

This type of fastener is intended for fastening with an increased strength limit. The force coefficient applied to stretching and shearing is significantly higher than that of a standard rivet. Therefore, the resulting connections are very reliable.

The reversible head, which is formed during riveting, securely connects the components and creates a strong connection that is not subject to vibration. This type of rivet is most often used in the mechanical engineering, aviation, etc. industries.

, that is, those where a strong connection of structures is required.

Source: https://crast.ru/instrumenty/iz-chego-delajut-zaklepki

Operating principle of threaded rivets, application and types

Bonding of metal (and other) parts is carried out using a variety of methods. Using a welding machine is not always possible (for example, in situations with plastics) or impractical, as is cutting threads for screws or bolts with preliminary drilling of the material. Special threaded rivets have virtually no restrictions in their use and provide reliable fixation at the joint. What kind of products these are and what is their feature is the topic of this article.

In fact, it is a hybrid of a traditional rivet (“hammer”) and a threaded fastener. Do not confuse such products with exhaust hoods!

Advantages of threaded rivets

• Simple installation technology.
• Possibility of reliable fastening of parts made of materials of increased fragility or low thickness (for example, sheet metal). The threaded rivet practically does not cause their deformation.
• If the total thickness of the connected samples exceeds the length of the fastening element, then the so-called one-sided fixation is performed, without a through passage. At the same time, the quality of bonding does not deteriorate.

A reliable connection at the installation site is ensured by the thread, which in nut samples is located on the inner surface, in bolted samples - on the outer surface of the crushed part.

Types of threaded rivets

The assortment is so large that listing it in full is both impossible and makes no sense. Knowing what types of threaded rivets there are, it is easy to determine what exactly is needed for specific purposes.

According to the material of manufacture

Products made of non-ferrous metals are used in cases where the aesthetic component comes to the fore. Therefore, such rivets are used mainly for decoration.

• Steel.
• Made from stainless steel.

These samples provide greater joint strength and increased corrosion resistance.

By type of thread

• Nut (M4 – permanent connection. It is advisable to use when it is impossible to access the back side of the part or in conditions of limited movement.
• Screw (M3 – 16) – collapsible type.

According to the profile of the leg

• Round.
• Hexagonal (to prevent rotation in the seat).

By type of pile

• Open or closed.
• Secret.
• Small or large.

By purpose

• Electrically conductive.
• With increased force (or pressing, or stretching).
• For highly leak-tight connections.
• With an enlarged head.
• With inch thread.
• With tags (allow for visual identification).
• With vibration isolation.

This list of varieties according to the specific application can be continued, but it is already clear that the industry produces threaded rivets for literally all occasions.

Specifics of working with fasteners

In principle, it is not much different from installing conventional rivets “under a hammer”.

Algorithm of actions for a rivet nut:

• Drilling a hole in the material.
• Installing a threaded rivet into a special tool.
• Placement in place (in the hole).
• Squeezing (compression) of the fastener.

For bolted:

Application

Basically, anywhere. As already stated, there are no restrictions. The main thing is to choose the right type and size. It is especially convenient to use threaded rivets to connect products, after installing them in place, access to the reverse side will be difficult or impossible.

Price

The price for such products is usually indicated for 1,000 pieces. Minimum - approximately 1,446 rubles (M4; 10 mm; for connecting parts with a thickness of 0.5 to 3 mm; steel).

The cost of riveters for threaded fasteners starts from 3,050 rubles (manual model).

Source: https://ismith.ru/material/rezbovye-zaklepki-princip-raboty-i-vidy/

2.2 Riveted connections

2.2.1 General information

Riveted joints are joints made using rivets.

Z

Rice. 2.25. Formation of the closing head during riveting

rivet - a round rod with heads at the ends, one of which is made in advance ( embedded head ), and the second ( closing head) is formed during riveting (Fig. 2.25).

The connection is assembled by installing rivets into pre-prepared holes in the parts (pack of sheets) and subsequent upsetting (riveting) with a special closing head tool.

During the riveting process, the package is tightened (compressed), and due to the transverse elastoplastic deformation of the rod, the initial gap between the rod and the walls of the hole is filled, often leading to the formation of tension.

Typically, rivets are used to connect sheet structures.

The connections are classified according to their purpose:

• durable – for load transfer;
• dense - to ensure tightness;
• durable - both for transferring loads and ensuring tightness.

Often glue is used to ensure a tight seal.

Advantages of rivet joints:

1. Stability and controllability of connection quality.

Disadvantages of riveted joints:

1. High labor intensity and low technology.

2. Increased metal consumption.

3. Inconvenient structural forms associated with the need to apply metal sheets or use special overlays.

Scope of application of rivet joints:

1. Riveted joints are used mainly in structures in which external loads act parallel to the joint plane, and the use of welding, soldering and gluing is impossible for structural or technological reasons.

2. Connections in which heating is not permitted due to the risk of tempering of heat-treated parts or warping of finished precision parts.

3. Connections of non-weldable materials.

4. In the aircraft industry.

5. In the automotive industry, for truck frames.

2.2.2 Rivet design

Rivets with a solid core : with a semicircular head (Fig. 2.26 a ) (GOST 10299-80, GOST 14797-85), which are mainly used in power and tight seams; with a semicircular low head (Fig. 2.26 b ); with a flat head (Fig. 2.

26 in ) (GOST 14801-85), designed for work in corrosive environments; with a countersunk head (Fig. 2.26 d ) (GOST 10300-80, GOST 14798-85), used when protruding parts are not allowed (in particular, in aircraft); with a semi-concealed head (Fig. 2.

26 d ), for joining thin sheets.

A	b	V	G	d
Rice. 2.26. Solid shank rivets

Rivets with a solid shank are manufactured with normal accuracy and high quality (for critical connections).

Semi-hollow rivets (GOST 12641-80 - GOST 12643-80) and hollow rivets (GOST 12638-80 - GOST 12640-80) are used for connecting thin sheets and non-metallic parts that do not allow heavy loads.

A	b	V
G	d	e
Rice. 2.27. Semi-hollow ( a - c ) and hollow ( d - f )

Semi-hollow and hollow rivets can have a semicircular (Fig. 2.27 a , d ), flat (Fig. 2.27 b , d ) or countersunk (Fig. 2.27 c , f ) head.

In addition to traditional rivets, the following are used:

rivets from rods with simultaneous riveting of both heads and the formation of a guaranteed tension along the cylindrical surface;

rivets with a countersunk head and a compensator - a local convexity on the head, deformed during riveting and sealing the contact of the head;

rivets for seams with a one-way approach and with a core that, during axial movement, expands the rivet, forms a closing head, and is then cut off and milled to provide a smooth surface;

an explosive rivet of the same purpose, in which the closing head is formed as a result of the explosion of a substance placed in the hole of the rivet. The explosion is caused by heating the embedded head and rod;

rivet bolt in the form of a rod, installed with interference, and a high washer. When installing the bolt, the nut is pressed onto a rod that has annular grooves in this place, while the tail part of the rod is torn off;

A high shear strength rivet in the form of a solid hollow rivet with a countersunk head held in place by a screw.

2.2.3 Rivet materials

Requirements for the rivet material: strength, ductility to ensure ease of head formation, homogeneity with the material of the parts being connected to avoid electrochemical corrosion.

Steel rivets are usually made from steels St2, St3, 09G2, etc. To connect elements made of high-quality steels, it is advisable to use rivets from the same steels, if possible due to the conditions of their plastic deformation.

Light alloys include brass, copper, and aluminum alloys. Usually B65, D15, etc. are used.

Steel rivets with a diameter of up to 810 mm and rivets made of light alloys are riveted using the cold method, while other rivets are riveted using the hot method.

2.2.4 Design of rivet joints

Riveted connections are divided by design into overlapping connections (Fig. 2.28 a ), connections with one overlay (Fig. 2.28 b ) and connections with two overlays (Fig. 2.28 c ).

A	b	V
Rice. 2.28. Main types of rivet connections

Typical examples of power rivet connections are beams, trusses, columns in existing building connections (Fig. 2.29).

A	b
Rice. 2.29. Riveted beams ( a ) and truss assembly ( b )

When designing, you should adhere to the following rules:

a) in elements working in tension or compression to reduce their bending, rivets should be placed as close as possible to the axis passing through the center of mass of the sections, or symmetrically relative to this axis;

b) in each connection, to eliminate the possibility of relative rotation of the parts being connected, it is advisable to use at least two rivets;

c) if possible, rivets should be placed in such a way that the elements being connected are weakened less and their material is used more fully, i.e. You should prefer a checkerboard arrangement to a row one.

The diameter of the rivets d in single shear force connections is chosen to be d = (1.82) s , in double shear connections – d = (1.21.8) s , where s are the thicknesses of the elements being connected; large values ​​– for small s . In the aircraft industry they accept .

The minimum spacing of rivets is determined by the convenience of riveting, the maximum by the conditions of close contact of the sheets and depends on the rigidity of the elements being connected.

2.2.5 Calculation of rivet joints

When a rivet joint is loaded with a longitudinal force F (within the limits of friction forces on the contact surface), the load is transmitted by friction forces, which in hot riveted joints without embossing correspond to a conditional shear stress of the rivet of 8090 MPa. Then the body of the rivet begins to take part in the work, undergoing bending, crushing and shear.

In tight and precise connections, it is necessary that the entire external load is absorbed by friction forces to avoid local shifts.

2.2.5.1 Calculation of rivet joints under lateral load

The calculation of rivets in a connection under the influence of a longitudinal load (Fig. 2.30) is reduced in form to their calculation for shear and crushing.

Shear stress:

,

where is the cut area;

– rivet diameter;

i – number of cutting areas;

– permissible shear stresses for the rivet material.

A	b
Rice. 2.30. Calculation diagrams of single-cut and double-cut rivet joints

Collapsing stress:

,

where is the crumpled area;

s – thickness of the connected part;

– permissible bearing stresses.

The crushing stress acts in two directions. The crushing acts equally on both the side surface of the rivet and the inner surface of the hole in the part. Therefore, the permissible stresses of the weaker material are taken as the permissible bearing stresses. If the material of the parts being connected is the same, but the thickness is different, then a smaller area is taken as the calculated crushing area, for example, if (Fig. 2.30 b ), then.

2.2.5.2 Calculation of rivet joints under the action of longitudinal load

When the rivet works to tear off parts (Fig. 2.31), the rivet rod experiences tension, the lower surface of the rivet head is crushed, and the head is sheared along a cylindrical surface, which is a continuation of the rod.

Tensile stresses in the rivet shank:

,

where is the cross-sectional area of ​​the rivet rod.

Collapsing stresses on the bottom surface of the head:

,

G

Rice. 2.31. Calculation diagram for tear-off operation of the rivet

de is the area of ​​the crushing surface.

Head shear stress:

,

where is the cut surface area.

2.2.5.3 Calculation of group rivet connections

The calculation of a group rivet connection comes down to determining the maximum load per one rivet and calculating it as a single rivet. Design diagrams are drawn up according to the rules for group threaded connections (see clause 2.1.10).

Source: https://studfile.net/preview/5582891/page:7/

Types of riveting

Adhesiveness is one of the methods of permanently connecting parts and assemblies using riveted rivets.

Rivets for metal aircraft are made from steel grades S15A (Select), 30KhMA, 3KhGSA and from aluminum alloys grades DZGT, D16, D17, D18 (Fig. 175).

rice. 175.

To connect with rivets, first drill a hole (Fig. 176), into which a rivet is inserted, consisting of a rivet head 1 and a rod 2. By riveting the protruding part of the rod, a closing head 3 is formed. Both rivet heads can protrude above the joint surface (regular rivet), or one head (less often both) is located flush (Fig. 177 and 178).

rice. 376.

rice. 177.

rice. 178.

rice. 379.

There are two riveting methods:

1) English, when blows are applied to the mounting head 1 and the closing head 3 is obtained as a result of the impacts of the rod 2 on the support 4 | (Fig. 179);

rice. 380.

2) German, when the blows are applied from the side of the rod 1, where the closing head 2 is formed, and the locking head 3 is located on the support 4 (Fig. 180).

Riveting is done by hand hammer, pneumatic hammer or riveting press, or by blasting.

For riveting by means of an explosion, special explosive rivets are used, which differ from ordinary ones in that a recess (chamber) is made at the free end of the rod, filled with an explosive of a special composition (Fig. 181).

rice. 181.

rice. 182.

When the closure head is heated with a special electric heating device, heat is transferred through the rod to the explosive and it explodes. The resulting gases distribute the end of the rod, forming a barrel-shaped closure head (Fig. 182).

Handmade English riveting (open)

The English riveting method is the most common in aircraft construction. Using this method, you can rivet parts in various conditions: 1) the part is secured in a vice (with padding jaws) or in a special device (slipway), and the support is in the hands of a helper; 2) the part is suspended and the support is fixed. In this case, the hammer can be in a horizontal or vertical position. The work is carried out by two people (a riveter and an assistant) or only one riveter.

Read also: Pipeline assembly

Equipment, tools and accessories

A workbench with a vice or a tripod, a special device (a slipway), a hammer, crimping, support.

The parts are fixed in the slipway, the hammer position is horizontal.

1. Insert the rivet (Fig. 183).

2. Provide hammer and support. The Riveter applies with his left hand

crimping onto the rivet head, while a helper, on the other hand, brings support to the rivet rod. The hammer must be held with the right hand. The axes of crimping, support and rivets must be located strictly at right angles to the plane of the part.

3. Unfasten the rivet.

After the assistant places support under the rivet, the riveter must strike the crimp with a hammer (Fig. 184).

With the hammer in a vertical position, riveting is carried out in the same sequence.

rice. 184.

Source: https://arxipedia.ru/slesarnye-raboty/vidy-klepki.html

Types of rivets, characteristics, installation, applications

In the general family of fasteners, the rivet is considered one of the most reliable fastening options. It is distinguished by the possibility of forming a closed fastening bond, which determines the strength and durability of the connected structure. Another thing is that using the through fastening principle is not always technically permissible. However, there are different types of rivets, differing in design and other characteristics, which allows them to be used effectively in a variety of fields.

Main characteristics of fasteners

From the point of view of choosing this hardware, the main characteristic is size. Several parameters are taken into account, including the diameter of the rod. It can range from 1 to 36 mm with a length from 2 to 180 mm.

However, you should not think that greater thickness is directly related to the strength of the rivet. Steel rod parts with a thickness of 10 mm can be much stronger than copper tubular elements, the diameter of which exceeds 20 mm.

However, much depends on the nature of the loads applied - sometimes it is more profitable to use thin-walled tubular parts.

Models of rivets with a low semicircular head have a small range of thickness indicators - from 1 to 10 mm, and the length in this case varies from 4 to 80 mm. Products with a flat head have a thickness ranging from 2-36 mm with a length of 4-180 mm. The longest parts are semi-secret types of rivets that can be used in niches with a depth of about 200 mm.

There are many versions and modifications of this hardware. The standard is a spacer element, which is used in connecting loose, soft and brittle building materials. The reverse head of this rivet folds during installation, which allows the load to be distributed over a large area on the reverse side.

To work with wood, petal models are used. At the time of installation, the rod opens and forms petal folds, which, in turn, provide a backstop and fixation of the material. As a rule, these are aluminum rivets that can handle lightweight panels.

Multi-clamp products designed for joining materials of different thicknesses are also interesting. The formed unit in this case is universal, so it is often used where there is no clear idea of ​​the size of the workpiece. The most technologically advanced option is offered by the developers of cassette models.

In this design, the fixing thrust elements can be represented by dozens of levels. In this case, only one rod will act as the load-bearing basis.

Classification by material

Most rivets are made of metal. In particular, aluminum, steel, brass and copper are used. Almost all models of this type have high requirements in terms of corrosion protection. Aluminum and copper rivets are also characterized by ductility and low weight. Steel fasteners are more often used in structures where it is necessary to ensure sufficient strength.

The use of plastic rivets is also common. They are mainly made of polyamide, which is also capable of providing strong connections. Of course, in terms of strength, this option will be inferior to metal.

But if stainless steel galvanic rivets in the long term are not able to guarantee consistently high protection from moisture, then plastic is not initially involved in destructive reactions during such contacts. In addition, polyamide does not conduct electricity and interacts optimally with materials made from composites and fiberglass.

Today, technologists are developing methods for hot soldering plastic rivets and fixed composite materials, which completely creates a monolithic structure.

Blind and threaded rivets

The presence of threads makes rivets similar to other hardware, but in this case the method of double-sided fixation is implemented. That is, the body of the element is inserted into the prepared hole, after which the second part of the sleeve is inserted from the other side by twisting. This method has its advantages in the form of reliability and ease of implementation, but it is not always possible to implement it.

Therefore, exhaust models are more often used. If threaded rivets require twisting of an auxiliary element to ensure rigid fixation, then the pulling principle involves deformation of the structure at the end to create a stop.

This may be the mentioned spacer principle, or thickening of the tubular structure, as well as other methods of deforming the tip of the rivet in order to secure it.

Installation technique

The operation is performed in several stages. First of all, a drill creates a hole along the line of which the part will be inserted. Almost all types of rivets should be installed in niches whose diameter is 10-15% greater than the thickness of the rod used. The density of occurrence in this case does not matter. The fastener is integrated into the prepared hole so that its head is located on the back side of the working surface.

At this stage, installation approaches may vary. Threaded models can be fixed with your own hands, without the use of special tools. However, steel explosive rivets or spacer hardware are deformed only with the help of special devices. Riveting is done with electric hammers or a piston hammer, it depends on the type of fastener.

Where is the rivet used?

This fastener is mainly used in the construction industry and repair work. Massive structures cannot be connected using this technology, but decorative finishing materials in the form of panels, sheets and plates are often attached in this way.

The manufacturability and accuracy of fixation make it possible to use such hardware in production. For example, aluminum rivets reliably connect particleboard panels.

Steel elements are used on machine-building conveyors when installing metal sheets and parts.

Conclusion

The double-sided clamping method has many advantages over other fasteners. But he also has his own shortcomings. The fact is that most of the clamps of this type are not designed for dismantling.

For example, explosive types of rivets can be called disposable - in the sense that they can only be installed in one place without the possibility of reinstallation. This fact is important not so much economically as technically – as a nuance of constantly equipping the target part with hardware.

It will be possible to remove the rivet only by deforming the products being connected, but even in this case, further arrangement of the rivet connection with the removed hardware will be impossible.

Source: https://FB.ru/article/302532/vidyi-zaklepok-harakteristiki-ustanovka-oblasti-primeneniya

Solid blind rivets design materials application

Rivets are permanent, non-removable fasteners. Until recently, rivets were considered obsolete and uneconomical. However, in the last decade, rivets have been reinvented and a type of rivet called “blind rivets” has emerged. Currently, they are widely used, for example, in the automotive industry. The new rivets have also found their use, although in many ways limited, in construction.

Classic (solid) rivets

Classic rivets are the oldest and most reliable type of mechanical fastener. They require a pre-prepared hole and access to the connection from both sides. Before installation, a classic rivet consists of a cylindrical rod and a head at one end

Often classic rivets are simply called solid rivets. Solid rivets are classified by head shape and shank shape. The most commonly used solid rivets are round and flat heads, and sometimes also countersunk.

In addition to completely solid rods, semi-tubular and tubular (hollow) rivet rods are also used to reduce the effort required to form the second head.

The characteristics of a rivet joint, including strength, significantly depend on the type of rivet, its material and shape.

Figure 1 - Various types of heads and shanks of solid rivets

When installing a solid rivet, a second head is formed from its rod by plastic deformation, which tightens the materials. Because the installed rivet has heads on both sides of the joint, it can carry tensile loads (along its axis), but is designed primarily to resist shear loads (perpendicular to the axis). Bolts and screws, on the other hand, are designed primarily to resist tensile loads.

The process for installing a rivet depends on the type of rivet shank. The rod of a solid rivet expands in the hole during riveting and completely fills it, which ensures a tight and reliable connection (Figure 2).

In the case of a semi-tubular rivet, the back of the shank flares out and creates forces that press the materials together, while the diameter of the shank inside the hole remains virtually unchanged.

Therefore, semi-tubular and tubular rivets are often used to create an axis between elements that rotate relative to each other.

Figure 2 - Installation of a solid rivet

In aluminum structures, aluminum rivets are used almost exclusively with cold installation, that is, without preheating them. They are used where reliability and safety are required, such as aircraft load-bearing structures and critical automotive components.

Types of Blind Rivets

Figure 3 - Various types of blind rivets

The main feature of blind rivets is that these fasteners are installed and riveted on one working side using a pre-prepared hole. The designs and installation methods of blind rivets have many variations (Figure 3). However, only some of them are used for structural, load-bearing connections, the rest - for auxiliary, decorative purposes.

Standard (blind) rivets

The main type of blind rivets that are used as structural fasteners are the breakaway blind rivets. We call them “blind rivets”

Standards and terms

Figure 4 — Terms according to GOST R ISO 14588-2005:

In the Russian version of the international ISO standard, GOST R ISO 14588-2005, the official general name for all such rivets is: “blind rivets” (Figure 4).

In the English version of the DIN 7337 standard, which has already been replaced by European (international) standards, this type of rivet was called “break mandrel blind rivets”, that is, “blind rivets with a tear-off core.”

The American industry standard IFI 114, which was the first standard for such rivets, calls them “break mandrel rivets.” In practice and, often, in technical literature, these rivets are called “blind rivets”.

1 — body of a “blind” rivet, 2 — end of a “blind” rivet, 3 — head of a “blind” rivet, 4 — shank of a “blind” rivet, 5 — core of a “blind” rivet, 6 — core, 7 — head of a core,

8 - core separation zone, 9 - core shank, 10 - core end.

Advantages of blind rivets

The three main reasons for using blind rivets are:

• Low installation cost. Other methods of joining materials—welding, screws, bolts and nuts, and solid rivets—require more human labor.
• Manifold. Blind rivets are available in many types, sizes and material combinations to suit specific design requirements.
• Reliability. A correctly selected and installed blind rivet can withstand high mechanical loads and harsh climatic influences.

Limitations of blind rivets

However, blind rivets have their limitations:

• The strength of rivets is limited by the strength characteristics of the materials used in it and the features of its hollow shape.
• Can only be used for joining relatively thin materials.

Installation of blind rivets

Blind - blind - rivets are installed in a tight hole that passes through the materials being joined (steps 1 and 2) - Figure 5. A rivet tool, called a riveter, grabs the tail of the core and pulls it towards itself, while holding the rivet in place (step 3 ).

As the core is pulled, it deforms the rivet and forms the back, blind head of the rivet. At a certain moment, the core breaks off and part of it, together with the head, remains in the rivet (step 4). The rivet head formed at the back of the joint firmly presses the materials together.

Core breaking force

The force required to tear off the core is given by the amount of deformation required to form the rear head of the rivet and the diameter of the groove (notch) on the core. The core rupture force is set in such a way that:

- firstly, to avoid creating too much clamping force, which could damage the materials being joined, and

- secondly, its size was sufficient to perform a tight connection of materials.

Rivet connection thickness

Figure 6—Gripping a rivet connection

Blind rivets are designed to join together materials with a specified overall thickness. The amount of deformation of the rivet body that occurs during its upsetting depends on this thickness (Figure 6).

If the rivet is too long, there will be too much rivet material left on the blind side of the joint and more force will be required to break the core.

If the rivet is too short, there may not be enough rivet material on the "blind" side of the joint to ensure a tight connection between the materials.

Types of blind rivet heads

Figure 7 - Main types of heads

Blind rivets have several types of heads (Figure 7). Flush heads are designed for applications where the rivets must not extend beyond the plane of the surface. Wide heads are used for fastening softer materials to increase the contact area.

a - standard, b - hidden, c - wide

Materials of rods and cores

Blind rivets have earned their popularity due to their ease of installation and the variety of shapes and materials used. The use of blind rivets in a wide variety of industrial and construction areas creates a need for rivets made from various types of materials.

Typically, the deciding factors when selecting materials for the components of a blind rivet—the rivet itself and the core—are strength, corrosion resistance, and the materials that will be joined by the rivet.

Materials of rods and cores:

• Aluminum-magnesium alloys (5xxx series): AlMg2.5; AlMg3, AlMg5.
• Galvanized carbon steel.
• 304 or 316 stainless steels.

Galvanic corrosion on rivets

When dissimilar metals are in contact in the presence of some electrolyte, they undergo galvanic corrosion, with one metal corroding more quickly and the other more slowly.

The rate of corrosion depends on:

• differences in chemical potentials of metals;
• degree of electrical conductivity of the electrolyte and
• relative sizes of areas of contacting metals.

Blind rivets can be used with a variety of materials such as aluminum, stainless steel, mild steel, galvanized steel and copper. When using rivets in humid, chemically contaminated and marine atmospheres, measures must be taken to minimize galvanic corrosion:

• avoid the formation of a joint from dissimilar metals by correctly selecting the material of the rivet body;
• install a barrier between dissimilar materials, for example, in the form of a layer of paint, a plastic washer or a rubber seal;
• take measures to install drainage to allow water and other electrolytes to exit the structure.

Galvanic compatibility of metals

Aluminum rivets can be used without restrictions for fastening aluminum parts and materials.

Rivets made of 304 and 316 stainless steels are used without restrictions for fastening stainless steels. The use of stainless rivets for connecting parts made of aluminum alloys and galvanized steel is possible only in rural areas and areas with a dry climate and a slightly polluted atmosphere.

"Getting" the rivet

Figure 8 - Main types of rivet grips

The technical characteristics of any blind rivet include minimum and maximum grip of the materials being fastened. In English it is called "grip". The maximum grip is the thickest combination of materials that a given rivet can hold together. The minimum grip is the thickness for which it is necessary to use a shorter rivet from the existing rivet size range.

For example, a rivet with a minimum grip of 6 mm can be used for a smaller thickness, on the back side of the rivet there will be more body of the rivet than there should be for a normal size rivet (Figure 8, a) and b)). Sometimes this excessive length can interfere with adjacent structural parts.

The so-called “multi-grip” rivets are more universal in this sense and can work in a wide grip range (Figure 8, c)), but they are more expensive.

Blind rivet hole size 

The correct hole is very important to obtain maximum load-bearing capacity of the blind rivet. Even a small increase in size can lead to a sharp decrease in the load-bearing capacity of the rivets, both for breaking and shearing. Therefore, when installing rivets, use precisely specified drill sizes and a good drilling tool to avoid getting a broken hole, as shown in Figure 9b.

Figure 9 - a - normal, b - not allowed

Do not rivet materials together

Like many other fasteners, rivets are not designed to pull materials together. They should be used when the materials being fastened are already temporarily pressed together in one way or another.

If you try to pull the materials together using a rivet, the rivet may begin to form a back head between the materials, as shown in Figure 10.

This defect is very difficult to eliminate, so to do this you need to drill out the rivet, remove the remains of the rivet between the materials, drill a hole with an increased diameter and install a new rivet with an increased diameter.

Source: http://metalvis-yug.ru/novosti/zaklepki-sploshnye-i-slepye

Rivet

A rivet is a type of fastener, a part of a riveted connection in the form of a round rod or pipe, on one side having a filling head and a closing (upsetting) head formed during the riveting process.

Description[ | ]

There are a large number of varieties of rivets, each type has some advantage over others.

Examples of rivets: conventional (classic) hot and cold rivets - general use; rod rivets - highly loaded connections; tubular and semi-tubular rivets - low-load connections, high-performance riveting process; piston rivets - connecting soft materials; blind rivets (pull) - the ability to create a connection with access from only one side; explosive rivets; rivet bolt, etc.

The most famous structures created using rivets are the Eiffel Tower in Paris, the Shukhov Tower in Moscow and the Harbor Bridge in Sydney Harbour.

Nowadays, the riveting process has been replaced by bolted joints and welded joints, mainly due to the slow process of assembling the structure and the tiring noise for the worker. It is a permanent connection.

"Blind" rivets[ | ]

“Blind” rivets are designed to connect parts even when access to the joint is possible only from one side[1].

Recently, embedded tubular rivets, pull (traction) rivets, which are a tube flared on one side with a punch (rod with a ball at the end) inserted into it, have become widespread. A hole is drilled in the parts to be fastened, a rivet is inserted, and a punch is pulled out with a special tool.

The ball expands, forming a closing head in the tube, thereby reliably securing the part, and comes off the rod. For example, the computer system unit in most cases is assembled using them. There is a modification with a sealed rivet, where the outer tube is a closed cavity in which the ball moves.

This type of rivet is called closed.

Holniten[ | ]

Holniten is a type of rivet for permanently connecting parts in leather goods, footwear and clothing. Widely used in jeans.

Holniten consists of a hollow rivet and a head, which is a sleeve with a cover [2].

Notes[ | ]

1. GOST R ISO 14588-2005. — “Blind” rivets. Terms and Definitions. Retrieved January 7, 2017.
2. GOST 15470-70. Accessories for products of the leather and haberdashery, textile and haberdashery, footwear and clothing industries. Terms and Definitions

Literature[ | ]

• Orlov P.I. Fundamentals of design: Reference and methodological manual. In 2 books, Book 2. - ed., 3rd revision. - M.: Mechanical Engineering, 1988. - P. 544. - ISBN 5-217-00223-9.

Source: https://encyclopaedia.bid/%D0%B2%D0%B8%D0%BA%D0%B8%D0%BF%D0%B5%D0%B4%D0%B8%D1%8F/%D0% 97%D0%B0%D0%BA%D0%BB%D1%91%D0%BF%D0%BA%D0%B8

Rivets: purpose, types, materials of manufacture

A rivet is a fastening element made in the form of a pipe or a round rod, which is usually used in places where welding is difficult. Riveted connections are also used where it is necessary to avoid overheating or changes in the structure of materials that are in close proximity to the place of production work.

This product is most often used in instrument making, mechanical engineering, as well as in the chemical, electronics, shipbuilding and food industries.

In addition, rivet joints are used in the construction of bridge structures and other structures. It was this product that was used in the construction of the world-famous Eiffel Tower.

Kinds

Currently, the following types of this product are used in industry:

• classic;
• exhaust;
• threaded;
• tubular.

Classic rivets with a head are used to create permanent connections. For this, as a rule, a hammer is used. Such fasteners are designed for connecting thin metal sheets, facade plates and other structures.

Blind rivets are considered the most convenient and practical fastening element. They can be used in cases where access to materials is possible only from one side. This rivet connection is very often used for fastening fragile and soft products.

Threaded rivets are used for very thin materials. They allow you to create not only a rivet, but also a bolted connection. Typically, such products are made of stainless steel, copper or aluminum. A riveter is used to install pull-out and threaded models.

Tubular rivets are used in fastenings that have minimal mechanical load. These fasteners have a through hole and do not have a head. The peculiarity of this type is that it can only be used if the connection is accessible from both sides.

Manufacturing materials

The strength of rivets directly depends on the material of manufacture. Today they are made from aluminum alloys, copper, stainless or galvanized carbon steel. Aluminum is usually used in construction work.

They are characterized by a high level of corrosion resistance. Stainless steel fasteners also have excellent anti-corrosion properties and very high strength. Galvanized hardware is used to fasten sheet materials to various structures.

Copper rivets are used in the installation of roofing and copper gutters.

Articles about products 09.20.2019 14:24:02

Only registered users can leave reviews. Please register

Source: https://Krepcom.ru/blog/products-articles/zaklepki/