Rivet and its calculation
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Types of rivets
There are three types of rivets.
This is a standard driving rivet with different heads:
- a rivet with a semicircular head is used to connect metal structures and is used in mechanical engineering, aircraft manufacturing and other types of production, for example, in construction;
- a rivet with a countersunk head, used for joining sheet steel, used mainly in construction;
- a rivet with a flat or semi-countersunk head is used in the construction of ships, in the construction of bridges and the like;
- The rivet is hollow and has a semicircular head.
Blind rivet, for connections in which riveting occurs on one side, in cases where work on the other side is impossible.
The most common and universal of them are traction rivets.
Pull rivet
They are used for mechanical assembly work, and are also used for installation of structures in construction.
There is a type of closed rivet that ensures the tightness of the seam.
Pull-out closed rivet
There is no hole through when using this rivet. The seams obtained using this type of product resist vibration well and are used in the production of refrigerators for various purposes, for refrigerated vans, ventilation and air-conditioning systems, in the production of railway carriages and similar industries.
A reinforced rivet, also called a monoblock, like the previous one, can be used to ensure that the seam is airtight. But in addition to this ability, it also gives special strength to the connection and the ability to withstand, in addition to destruction from vibration, shear destruction. You can join more than two sheets of material. It is used in the manufacture of container boxes, cabins and bodies for some types of cars.
Reinforced blind rivet or monoblock
If you have to connect surfaces made of thin metal, use a multi-clamp rivet. It is used to join sheet metal and plastic, for example, in window frames, and the materials can be of different thicknesses, since the rivet distributes the pressing force evenly.
Multi-clamp rivet installation diagram
However, such a connection will not be airtight like the previous options. This is especially true for open type rivets.
A screw rivet is a type of threaded connection. Parts assembled using such rivets can be disassembled if necessary.
There may be several types. For hermetically sealed connections of thin sheet metal with a thickness of 0.5 mm or more, closed cylindrical rivets or cylindrical sleeves are used. Open type rivets have a threaded hole through them. Can be used in cases where it is impossible to cut a thread on a product. Their external surface is made smooth.
There is a type of product in which the outer surface is made with corrugation. They can have beads of a standard size, reduced or enlarged, and can also have a hidden bead shape.
Open type rivet with collar and notches
This product can be used for any round shaped holes to form threads into them. Thanks to the notches, the possibility of twisting under load is eliminated.
For hexagonal holes, rivets are used - hexagons and half-hexagons.
Standards and GOSTs defining the size and shape of rivets
All fasteners must be produced in accordance with standards that are approved in Russia and comply with international standards in order to avoid misgrading.
Standard driving rivets with a semicircular head and accuracy classes B and C must be produced in accordance with GOST 10299-80, which corresponds to DIN 660.
Drawing of a driven rivet in accordance with GOST 10299-80
According to it, the diameter of the working rod can be from 1 to 36 mm and the total length from 2-8 to 55-180 mm. The material for its manufacture can be: carbon steel, stainless steel, copper, bronze and aluminum.
A countersunk rivet with manufacturing accuracy class B and C must be manufactured in accordance with GOST 10300-80 or the corresponding DIN 661. This standard is in compliance with ST SEV 1020-78
Rivet with countersunk head according to GOST 10300-80
The dimensions of the rivets and its length are similar to the previous type, the only difference is in the maximum length, here the value is from 60 to 180 mm.
The semi-countersunk head, or as it is also called a reduced semi-circular head, must comply with the standards set out in GOST 10301-80 and DIN 662
Type of rivet with a reduced semicircular head according to GOST 10301-80
The product must comply with the international standard ISO 1051. The product is manufactured either by cold heading or using automatic lathes. The dimensions are the same as in previous types.
GOST 10302-80 is adopted for the production of rivets with a semicircular low head, and GOST 14797-85 for rivets with a semicircular head and high requirements for quality and reliability.
Semi-hollow rivets with a semicircular head must comply with the technical conditions set out in GOST 12641-80
The diameter of the rod in this type is from 1 to 10 mm.
Semi-hollow rivets with a flat head are manufactured in accordance with GOST 12642-80 and have two designs.
A semi-hollow rivet with a countersunk head must meet the parameters of GOST 12643-80.
A completely hollow rivet with a rounded head is manufactured in accordance with the technical specifications of GOST 12638-80.
The hollow rivet with a flat head complies with GOST 12639-80, and with a countersunk head GOST 12640-80.
The threaded nut rivet is manufactured in accordance with the German standard DIN 7338
A blind rivet must meet the technical characteristics shown in GOST R ISO 15973-2005 and DIN 7337. According to the standard, they are called blind rivets with a closed end, a bursting pull core and a protruding head.
According to the explanations, the maximum diameter of the rivet body is calculated using the formula:
d(max) = d (nom) + 0.08, and the minimum is calculated accordingly:
d(min) = d(nom) – 0.15
Also, other types of these products can be manufactured in accordance with OST, for example OST 1 34075-85, rivet with a flat rounded head, OST 1 34077-85 and so on.
Rivet production
Riveted joints, despite the fact that other technologies for joining metals have appeared long ago, are still successfully used. This type of connection, judging by the data of archaeological excavations, appeared more than 2000 years ago.
When connecting with a rivet, the metal is not subject to heating (except for a special technological process), and therefore is not subject to deformation. Heating is accompanied by a change in technological properties near the seam zone, as the grain structure changes. In addition, if it is welding alloy steel or stainless steel, “burnout” of the alloying components occurs. Welding aluminum and its alloys, as well as welding cast iron, has its own problems.
A rivet is an ideal option when you need to connect parts that cannot be welded, as well as parts that are located in places that cannot be reached with any welding machine.
Of course, the process of joining using the rivet method itself is very slow compared to the welding process. You need to make holes on the parts, align them, install rivets there and perform riveting.
Rivets are used in critical parts in rocketry and aircraft manufacturing. With their help, various tanks are made, both fuel tanks in airplanes and large containers. A seam made using rivets does not change in quality, and there is no corrosion or metal fatigue.
That is why the quality of the manufactured rivet must be taken very seriously and a homemade rivet can only be used for household purposes for unloaded connections.
When connecting with a rivet, it is inserted into the hole with the end that does not have a head. Then, with a special tool, manual or mechanized, this end is riveted until it becomes deformed and forms, as it were, a second cap. The connection is very tight.
Rivets are made using the technology of cold stamping of a rod from the appropriate metal. Since this part must have a set of certain qualities in terms of material resistance, calibrated rods are preliminarily subjected to heat treatment, by annealing and subsequent cooling, at temperatures that correspond to the technological process. The rods are then pickled to remove scale.
Using special knives, similar to guillotine shears, the rods are cut into blanks, then a head is formed on a press, and the formation of a head with a stepped rod makes it possible to obtain products with less waste. After this, the product is moved to a tumbling drum for chip processing. If the product is made of ferrous metal, it is galvanized yellow or white, lubricated and packaged.
Also, driven rivets can be produced using special automatic lathes.
Companies producing rivets
Rivets are products whose quality determines the longevity of the entire structure. For example, the TV tower is made using rivets, and of course, not only that. The skin of the aircraft, gas tanks - all these are rivets.
They are produced by both Russian and foreign enterprises.
Drive-in rivets are produced in the city of Kovrov by the Spets-Metiz plant; drive-in rivets in accordance with more than 10 GOST standards are produced in the city of Rybinsk by Logcompany, not only from steel, but from non-ferrous metals.
DMZ LLC in the city of Degtyarsk also produces, in addition to driven rivets, hollow rivets.
The Penza plant PMZ has the same assortment, PP Standard from the city of Revda, Russpetskrepezh from Taganrog, Elektrosignal from Novosibirsk, and the Shatkovsky normal plant offers 24 types of rivets manufactured according to industry standards.
Closer to the center, these products are produced in Moscow and St. Petersburg. Rivet nut, both with smooth walls and with notches, blind rivet is offered by many wholesale companies.
It is difficult to buy a good blind rivet, just like a screw rivet. You can buy a product made in Taiwan and China, they cost the same price as a Russian manufacturer. German, Swiss and Finnish, as well as Turkish products are more expensive, but they are of much better quality.
Source: http://themechanic.ru/ves-zaklepki
How to rivet rivets with a hammer
Hammer rivets have been an integral part of every builder's kit for quite some time. At their core, they are a kind of rod, on top of which there is a special head, which can be made in the form of various shapes (the most common are round).
Hammer rivets are used to create a reliable connection. To do this, the builder must have access to all sides of the elements that need to be connected. It is important to note that the holes in the materials being joined must be similar to the diameter of the rivet (possible errors are determined by GOST).
Rivet sizes can vary significantly. Thus, the diameter ranges from 1 to 36 millimeters, and the length ranges from 2 to 180 millimeters. This spread makes it possible to use parts in various fields to connect materials of different thicknesses.
However, at the same time, it is worth remembering that the size must correspond to the loads that the rivets will experience during operation. This is why experienced builders often advise and recommend using rivets with a “size margin” - it is better to take a larger part than a smaller one.
In general, all the requirements put forward for these building elements are specified in the relevant construction GOSTs adopted by the Russian Federation, and are also established by various documents legalized at the international level (for example, the production of hollow rivets is regulated by GOST 12639-80).
Material of manufacture
Hammer rivets can be made from various materials. For consideration are the most popular varieties.
Aluminum
This type of building parts is also often called exhaust. Their production is regulated by several domestic standards:
- with countersunk head - GOST 10300-80;
- with semicircular – GOST 10299-80;
- with flat – GOST 10303-80;
- semi-hollow - GOST 12641-80.
The size grid is quite varied: diameter - from 1 to 10 millimeters, length - from 5 to 45 millimeters. Moreover, these indicators may vary depending on the type of rivets (hammer, pull, threaded).
It is also important to note the fact that such aluminum parts can be made from several grades of material. Thus, the most popular raw materials are considered to be aluminum grades D18, V65, AMts, D19P, AMG 5P. They can also be duralumin.
Steel
Stainless steel parts occupy a special place among all hammer rivets. The production of these elements is carried out not only in Russia, but also abroad.
Most often, steel rivets are produced without any additional coating, and their sizes may vary. So, for example, the diameter of the cap can be from 1.8 to 55 mm, the height of the cap can be from 0.6 to 24 mm, the height of the entire element can be from 2 to 180 mm.
Due to such diverse indicators, these parts can be used for connecting sheets made of metal, for fastening facade plates to substructures, as well as for connecting metal structures with parts made of other materials.
Copper
Construction parts made from this material are characterized by several distinctive features:
- due to their antimagnetic properties, they are widely used in the radio industry;
- due to the fact that copper does not rust, rivets made from it are in demand in almost all areas (especially in cases where the materials fastened with them often come into contact with water and air);
- Copper elements are used to assemble apparatus and tools for the chemical industry, as they are quite resistant to the action of various substances manufactured artificially.
Most manufacturers produce copper rivets in standard sizes: from 2 to 8 mm in diameter.
Brass
Brass parts are quite flexible, but at the same time durable. And thanks to their appearance, they can perform not only their direct functions, but also serve as a decorative or design element. Most often, such elements are used in the industrial and instrument-making fields.
The length of brass rivets reaches 4–70 mm, and the diameter is 2–8 mm.
In order to choose the right crimp (mandrel) for brass parts with a semicircular head, you should choose crimps that have:
- long service life;
- uniform hardening;
- working ends are polished;
- Impact heads are inductively annealed.
Countersunk rivets
Similar elements have other names - impact, driving. Riveting with this part is carried out in several cases:
- when welding is prohibited;
- when joining non-metallic materials.
Rivets can be riveted overlapping, end-to-end, as well as using the chain and staggered method.
For more information on hammer rivets, watch the video below.
A rivet is one of the simplest types of fasteners for creating permanent connections. In the general case, this is a rod or tubular part that has a supporting “embedded” head of a certain shape at one end. It is installed in the connection, as the name suggests, by the riveting method (as well as shrinkage, rolling, broaching, explosion).
Based on their shape, rivets can be divided into several main types:
- Rivets with a closing head (there are solid, hollow and semi-hollow)
- Rivets with broaches (also called tear-off or pull-out rivets)
- Threaded rivets (also called riveting nuts)
Rivets with locking head
Historically, rivets with a closing head were the first to be invented, which is why they became the most widespread. These rivets have a head on one side. The second head, called the closing head, is formed using a rolling or riveting tool: riveting hammer, pliers.
According to the shape of the head, rivets with a closing head are divided into:
They also differ structurally by the presence of a hole inside the rivet:
- Solid rivets - no hole
- Hollow rivets - tubular - have a through hole
- Semi-hollow rivets - for flaring - have a blind hole
Materials for rivets
Rivets with a closing head can be made from a variety of metals and alloys that lend themselves well to plastic deformation.
The most widely used materials are:
- Steels - mainly ductile high-boiling steels 03kp, 05kp, 08kp, 10kp, 15kp, 20kp
- Stainless steels - austenitic steels 12Х18Н9, 08Х18Н10, 03Х18Н11, 12Х18Н10Т
- Aluminum alloys - the most applicable alloys are AD , AD1 , aluminum-magnesium alloys AMg2, AMg5, AMg5P, AMg6, alloys AMts, V94, V65, D1, D16, D16T, D18, D18P, D19P are also used
- Brass alloys - mainly L63
- Copper - grades MT, M3
Marking of rivets by materials
Rivets can be marked on the head for subsequent identification. The marking can be convex or concave (branding).
The following is a table with the accepted marking of basic materials in the form of dots or dashes.
Source: http://gidpotolok.ru/info/kak-pravilno-klepat-zaklepki-molotkom/
How to correctly calculate the length of a hammer rivet
A rivet is one of the most convenient and quickest fasteners to install, providing a reliable permanent connection. Today there is a huge variety of shapes and sizes of riveting fasteners, but hammer rivets were the first to be invented.
They were used in the construction of ships, bridges and other metal engineering structures, where they successfully replaced welded joints.
Today, this oldest type of fastener is made from modern materials, so it has not lost its popularity and has even expanded its scope of application.
Operating principle of a hammer rivet
A classic hammer rivet is a rod with a rivet head of a certain shape (semicircular, countersunk, semi-countersunk, flat).
The closing head is formed from the opposite end of the rod by plastically deforming it using a riveting hammer and a special impact mandrel, which gives the head a neat semicircular shape.
In this case, massive support must be provided from the side of the mounting head. Obviously, to install such a rivet it is necessary to have access from both sides of the surfaces being fastened.
Determining the length of a rivet with a closing head
To correctly install the rivet fastener, it is important to accurately select its length so that it is possible to create a closing head of the required shape from the protruding part of the rod and obtain a connection without gaps. The length of hammer rivets produced varies from 2 to 180 mm and is selected based on the thickness of the package of materials being fastened.
First you need to determine the length of the protruding part of the rod (allowance). For the version with a semicircular head, the allowance is 1.21.5d, and for the version with a countersunk head - 0.81.2d, where d is the diameter of the rod. Based on the obtained allowance value, it is easy to calculate the total length of the rod by adding to it the thickness of the materials being riveted - S.
- Length calculation for round head rivet: L = S + (1.21.5d)
- Countersunk head rivet length calculation: L = S + (0.81.2d)
Calculation example:
It is required to rivet materials with a total thickness of 41 mm using a countersunk rivet Ø8 mm
L = 41 + 0.8 x 8 = 41 + 6.4 = 47.4 mm
Then we select from the existing standard range of rivet lengths the value closest to 47.4, that is, 48 mm. So, to create a hidden rivet connection of sheets with a thickness of 41 mm, we need fasteners of size Ø8x48 mm.
Hammer rivets come in a wide variety of diameters ranging from 1.0 – 36 mm. The diameter of the hole drilled in the materials must ensure free insertion of the rod, while the size of the gap between the body of the rivet and the walls of the hole must not exceed the parameters prescribed in GOST.
So, to obtain high-quality riveting, the gap for parts with a diameter of up to 5 mm is no more than 0.1 mm, and for parts from 5 mm in diameter is no more than 0.2 mm. When materials are riveted with a countersunk rivet, a chamfer is removed under the head in the hole at an angle of 60° - 90° to a depth corresponding to the height of the embedded head.
Useful tips 05/29/2018 11:08:07
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Source: https://Krepcom.ru/blog/poleznye-sovety/kak-pravilno-rasschitat-dlinu-zaklepki-pod-molotok/
Metal rivets sizes
Aluminum rivets are a widely used consumable material used for joining sheet metal parts. In a situation where welding is not permissible, this is the only possible solution. The main advantage of fastening with rivets is impact resistance and vibration resistance.
Specifics of this consumable
Aluminum rivets GOST are a type of hardware used for permanent fastening of various materials. Before using rivets, you need to check whether this connection method is suitable for specific parts.
This material is widely used in the creation of aircraft and ships, as well as in space, chemical and even food production.
An important point is the choice of the size of aluminum rivets. Their diameter depends on the magnitude of the expected load, and their length depends on the thickness of the elements being connected.
Advantages and disadvantages
Advantages:
- Aluminum is a ductile material. This makes it possible to quickly install fasteners. Therefore, one of the most important advantages of aluminum rivets is efficiency and low energy consumption.
- Proper installation ensures high strength of the resulting connections.
- Affordability.
- Affordable installation cost. It is ensured by the speed and ease of its implementation, the low price of the aluminum itself and the tools necessary for carrying out riveting work.
- Resistance to corrosion and aggressive substances.
- Environmental Safety.
- Low weight.
Flaws:
- Low strength characteristics of aluminum itself compared to copper or steel.
- Can be used only in the absence of significant, prolonged mechanical loads.
- Do not use with aggressive materials such as steel and titanium.
In the situation of joining such materials with aluminum rivets, it is necessary to carefully insulate the surfaces to avoid contact between metals. The insulator can be copper or rubber.
Types of aluminum rivet hardware
Today the following types of rivets are distinguished:
Under the hammer. Despite the fact that this is the simplest method of fastening, it still remains popular precisely because of its primitiveness. This method is used for permanently connecting various parts.
Its essence is as follows: holes are made in both metal sheets with a diameter equal to the diameter of the rivet. Next, the hardware is inserted and, using a hammer, the end without the head is flattened, thereby pressing the parts together. Hardware for such fasteners can be with a round or flat countersunk head.
Tubular (piston). As can be seen from the photo of aluminum rivets of this kind, they have a hollow cylindrical shape and there are no caps. They are also less durable. Used to join plastic and leather elements.
The operating principle of piston rivets is as follows: the hardware is inserted into the holes made in both parts and riveted using punches at both ends. The disadvantages of this method include low resistance to mechanical loads and the need to provide two-way access.
Mortgages. These are rivets of the piston type, into which a punch is pre-inserted. During installation, it becomes flattened.
Hardware of this type is convenient in situations where access to one of the sides of the elements being processed is difficult. The downside is that it requires a lot of force on the punch.
Threaded.
This is the best choice if you need to join two materials whose thickness does not allow threading. The threaded type rivet has an internal thread. It is screwed onto the tool and then inserted into the parts to be joined.
Next, the tool is unscrewed and the rivet is compressed along its length.
Exhaust. They are used when connecting particularly fragile and thin parts. Blind rivets are a sleeve with a punch. Their installation requires a special tool. The advantages of this method are the speed of installation and ease of riveting.
Remember, which aluminum rivets to choose depends on the specific characteristics of the fastener. Good luck!
Photo of aluminum rivets
Source: https://steelfactoryrus.com/klepki-dlya-metalla-razmery/
Rivet connections
2014-04-10 Riveted connections are a separate class of permanent connections. It is impossible to disassemble without breaking the fastenings. A rivet is a round rod with a head at the end. The part that is initially present in it is called the backfill, and the part that is formed after riveting is called the closing part. Heads may vary in shape. This connection is permanent. Therefore, it is impossible to remove rivets other than by drilling or cutting out.
Riveted connections are a separate class of permanent connections. It is impossible to disassemble without breaking the fastenings. A rivet is a round rod with a head at the end. The part that is initially present in it is called the backfill, and the part that is formed after riveting is called the closing part. The heads may differ in shape. This connection is permanent. Therefore, it is impossible to remove rivets other than by drilling or cutting out.
Connections using rivets - manually
The parts are fastened by drilling holes in them larger than the diameter of the rod, placing a rivet in it and connecting it. The parts are supported from below using a special recess to fit the shape of the head. Next, the free end is riveted.
Mechanized
For mass production, special tools and mechanisms are used. These can be riveting presses, automatic machines, pneumatic hammers. A standardization system is provided for working with parts using a mechanized method. GOST establishes the following main types of normal strength rivet connections:
- with semicircular head GOST 10299-80;
- with countersunk head GOST 10300-80;
- with semi-countersunk head GOST 10301-80.
There are elements containing explosives. They are used when the closing part of the head cannot be reached.
Riveting can be group or single-row. Using the first increases productivity. It takes place thanks to the press and the blows of several pneumatic riveting hammers. The closing head is formed by impact. Impact riveting is inferior in quality to press riveting.
Application of riveted connections
A high-strength connection of several parts, regardless of their material, can be achieved using a rivet. Therefore, riveted connections of parts are used in such areas as:
- aircraft manufacturing
- for materials that cannot be welded;
- automotive industry;
- connections where heating of the connected parts due to their deformation is unacceptable;
- shipbuilding.
Rivet joints are usually used for sheet fastening. The work is done in two different ways: hot or cold. The latter method is used for steel rivets with a diameter of no more than 10 mm, as well as those made of brass, copper and other light alloys.
Tubular rivets are used in parts with low loads. They are called pistons. Such parts can be metal or plastic, it all depends on the material that they will be held together.
Types of rivets
They can be distinguished by the type of rod:
- with solid;
- with a hollow core. They are used for non-tensile connections of structures made of metal or elastic metal.
- with a semi-hollow rod. The use of such rivets is advisable for joining composite materials. The void in the rod helps reduce the effort when riveting, reduces the rod diameter, and increases endurance.
- rivet bolts. Such riveted connections are used for metal structures, for example, for heavy floors.
Rivet bolt
This connection consists of two parts: a ring and a rod. This connection is made by a special device that clamps the lower end and makes a stop in the part, thereby creating a compression force on the rod. At the same time, a ring is put on the base, pressing both parts. At the same time, the middle section of the bolt is compressed, after which its tail comes off.
A connection made by a group of rivets is called a rivet seam .
Sutures can be divided depending on their purpose into:
- durable. These are used in the construction of bridges, floors, and also for moving cranes. This connection can withstand heavy external loads.
- dense. Their use is beneficial where it is necessary to create a sealed seam. These can be all kinds of vessels, tanks, tanks, the pressure in which is insignificant.
- durable. This type of connection ensures tightness. Finds application in steam boilers, pipelines with high pressure (for liquids or gases).
Rivet connections - classification
There are two types of fastening parts:
- overlap, in which one part is superimposed on another;
- end-to-end, in which the parts are brought to each other and connected using a third one superimposed on them. There may be several overlays.
Riveted butt joints using one lining are used in the seam structures of aircraft. It is well suited for hull and exterior cladding. In modern aerodynamics, such a seam is combined with hidden riveting. This fully meets the necessary requirements. Two linings for the joint of structures are used where structural elements experience great forces.
Seams can be divided into:
- single and double row;
- multi-row;
- parallel;
- chess.
Calculation helps to choose the right rivet for the part. Its diameter will depend on the thickness of the sheets being fastened, and is calculated using a special formula. The length of the rivet rod will be determined by the thickness of the sheets (plus the closing head). It is formed from part of the rod. Therefore, it can be semicircular, hidden or semi-hidden.
For automotive structures, a single or double row seam is usually used, and in a double row the rivets are placed in a checkerboard pattern.
Material
It may be different. Usually this is steel of different grades, mostly low-carbon and ductile, in rare cases alloyed. For fastening materials made of non-ferrous metals, rivets are used of the same type. Rivets made of brass, copper, and aluminum alloys are widely used. It is important that riveted connections of parts made of the same material are secured with the same rivets. Otherwise, electrochemical corrosion may occur.
Advantages of connecting with rivets:
- the ability to fasten parts that cannot be welded;
- use in structures subject to vibration or repeated loads;
- connection of elements for which high welding temperatures cannot be tolerated due to their possible deformation;
- simple technological design and simplicity of design;
- convenient quality control of products.
Flaws:
- increasing the mass of the product due to the connection;
- high manufacturing cost;
- complex technological process;
- the need to use expensive equipment;
- increased material consumption when using overlays;
- violation of the tightness of the seams during operation;
- Stress is concentrated in their connections, which leads to weakening of strength.
Riveted joints are being replaced by modern types of welding.
Rivet calculation
You can do it:
- tensile;
- to crumple;
- for cutting
It is also necessary for the length of the rivet shank. If it is too long, it may lead to distortions. And insufficient length will not firmly connect the entire structure.
Before using fasteners such as rivet connections, the advantages and disadvantages of which are already known, it is necessary to check their reliability.
Device recommendations
Many years of experience, as well as calculations, help in the arrangement of fastening parts, including using rivets. The following recommendations exist:
- fastening must be carried out with rivets of suitable strength;
- their arrangement is desirable in a checkerboard pattern, for less weakening of the structure;
- the use of rivets of different diameters in one connection is not recommended;
- The use of more than two rivets will help to avoid rotation of parts relative to each other’s arcs;
- the pitch is set based on their ease of installation and the strength of the parts themselves;
- even if you increase the rows of rivets in the joint on each side, this will not increase the strength of the connection, so their number should not be more than three;
- butt rivets require a larger number of rivets than the same, but overlapping;
- The tightness of tight joints can be increased by applying coatings or glue to the seam;
- It is imperative to calculate a sufficient number of rivets before starting to connect the structure.
Category : Articles about fasteners
Source: https://rumett.ru/under/krepezh/1462-zaklepochnye-soedineniya.html
Rivet connections of parts
Non-separable connections obtained by connecting parts with rivets are called rivets. Disassembling them is usually accompanied by destruction of the connection parts.
In modern mechanical engineering, riveting has been replaced in a significant number of cases by more productive electric welding. However, in a number of branches of mechanical engineering (for example, in aircraft manufacturing, automotive and tractor manufacturing, agricultural engineering) riveting is still widespread.
The peculiarity of the rivet connection is that this connection is strong and reliable, stable under shock and repeated variable loads. At the same time, checking the quality of the connection is simple and not labor-intensive; it is possible to connect any materials without changing their physical and chemical properties, including those that are usually not connected by other methods.
The place where parts are joined with rivets is called a rivet seam.
According to their purpose, rivet seams are divided into strong, from which only mechanical strength is required, and strong-tight, from which, in addition to mechanical strength, the tightness of the connection is also required.
Based on the type of connection between the sheets, there are two types of rivet seams: lap seams (Fig. 2, a), when one sheet is placed on top of another, and butt seams with one or two overlays (Fig. 2, b), when the sheets are brought end-to-end and joined by superimposing them. one or two pads.
Rice. 2. Types of joining sheets: a – overlapping, b – butting
In addition, according to the location of the rivets, the seams are divided into single-row, double-row, multi-row, parallel and checkerboard.
The main types of rivets used in modern mechanical engineering are shown in Fig. 3. The finished head of the rivet is called the embedded head, and the head obtained as a result of riveting is called the closing head.
Rice. 3. Types of rivets: a – with a spherical head; b – with a countersunk head; c – with a flat head; g – hollow; d – semi-hollow; e – special
When choosing materials, it is desirable that the linear expansion coefficients of the rivets and the parts being connected are approximately equal (to avoid thermal stresses). Combinations of dissimilar materials that form galvanic pairs should not be used in the connection (to avoid the occurrence of galvanic currents that quickly destroy the connections). For this reason, copper rivets are used to connect copper parts, aluminum rivets are used for aluminum parts, etc.
The quality of the seam is influenced by the correct choice of the size of the rivets and their location along the length of the connection.
Based on the calculation of the strength of connections and practical experience, the following is accepted:
Rivet diameter
or
where d is the diameter of the rivet, mm; δmin – smaller thickness of riveted sheets, mm; t – rivet pitch, mm.
The length of the rivet shank depends on the thickness of the sheets being riveted and the shape of the closing head. The closing head is formed from the protruding part of the rod. The length of this part of the rod to form a countersunk head should be from 0.8d to 1.2d, and to form a semicircular head - from 1.2d to 1.5d.
Depending on the diameter d of the rivet, the diameter of the hole d0 for the rivet is recommended to be d0 = d+(0.22) mm.
The distance from the center of the rivet to the edge of the sheet must be at least a = (1.52)d.
The thickness of the overlays located on both sides of the sheet is δн = 0.750.8δ and δн = 1.25δ on one side.
Rivet spacing for a double-row lap seam t ≈ (36)d, for a double-row seam with two overlays t ≈ 6d, for a single-row seam with two overlays t ≈ 3.5d (t = 3d+2 mm).
The pitch between the rows of rivets is t, when arranged in a checkerboard pattern - t ≈ (23)d0.
The required number of rivets m is determined by calculation.
Holes for rivets can be made by punching, punching or drilling. Recommended diameters of holes for rivets are in table. 1.
Table 1. Recommended diameters of holes for rivets, mm
Rivet diameter d | 6,0 | 7,0 | 8,0 | 10,0 | 13,0 | 13,5 | 16,0 | 16,5 | 19,0 | 22 | 25 | 28 | 30 | |
d0 | Precision Assembly | 6,2 | 7,2 | 8,2 | 10,5 | 13,5 | 14,0 | 16,5 | 17,0 | 20,0 | 23 | 26 | 29 | 31 |
Rough assembly | 6,8 | 7,8 | 8,8 | 11,0 | 1,4 | 14,5 | 17,0 | 17,5 | 21,0 | 24 | 27 | 30 | 32 |
1. Calculation of the strength of rivet joints
The main criterion for the performance of riveted joints is strength, and in calculations it is assumed that the stresses in the sections are evenly distributed.
Typically, riveted joints are loaded with forces acting parallel to the plane of contact of the parts being connected, so failure of the joint can occur as a result of the following reasons:
- cut of rivets along section 1–1 under the action of tangential stresses (Fig. 4, a);
- crushing of the holes of the connected parts and rivets under the influence of forces causing crushing stresses (Fig. 4, a), as a result of which the axes of the rivets are distorted, eccentric tension occurs, and the heads can be separated from the rod;
- rupture of the connected part along the section weakened by the holes for the rivets (Fig. 4, b);
- cut of the parts to be connected along two sections 2–2 (Fig. 4, b). As a result of the riveting process, the rivet shank shrinks (shortens and increases in diameter), causing the rivet material to fill the hole.
Rice. 4. Scheme of the action of forces in a rivet joint
Therefore, the calculation of the connection is carried out according to the diameter d 0 of the hole for the rivet. It is assumed that the load F is distributed evenly between the seam rivets. The frictional force that occurs between riveted parts is not taken into account when calculating strength.
In an lap joint (Fig. 4), the external force F forms a couple of forces, the moment of which, due to the small thickness δ of the riveted sheets, is neglected.
Then the calculation for the strength of the riveted joint will consist of:
1. Based on the calculation of the shear strength of rivets along section 1–1 (Fig. 4, a)
where Аср = 0.25iπd; i – number of cut planes; A – rivet cut area; m – number of seam rivets under symmetrically acting load m ≥ F/(Aav[τav]).
2. Based on the calculation of the strength of the connection against the crushing of the side surface of the rivets and the walls of the holes of the parts being connected (Fig. 4, a)
where Asm = d0δmin; δmin – the smaller thickness of the parts to be joined (the projection height of the rivet rod), the number of holes in the dangerous section of the sheet.
3. Based on the calculation of the tensile (tear) strength of the parts being connected along section 1–1 (Fig. 4, b), weakened by holes for rivets
where Ap = (b – d0m)δmin is the calculated area in the dangerous section of the sheet.
4. Based on the calculation of the shear strength of the parts being connected using rivets along section 2–2 (Fig. 4, b)
where A'av = 2(е – d0m/2)δmin (here the length of the e section is 2–2, reduced by d0/2, since the material first collapses by this amount, and only then does shearing occur).
Recommended values of permissible stresses are given in table. 2.
Table 2. Recommended values of permissible stresses in a rivet joint
Seam component | Type of permissible voltages | Method of making holes | Permissible stress values, MPa | |
St2, St10kp | St3, St20kp | |||
Construction details | Stretching[σр], | 140 | 160 | |
Slice[τavg] | 90 | 100 | ||
Collapse [σcm] | 210 | 240 | ||
Rivets | Slice[τavg] | Punching | 100 | 100 |
Drilling | 140 | 140 | ||
Collapse [σcm] | Punching | 240 | 280 | |
Drilling | 280 | 320 | ||
Note. For brass and duralumin - permissible stress values for St3/(1.52) |
Example. Lap rivet connection of two strips of duralumin b x δ = 350x12 mm with an applied force F = 250 kN.
Calculation
Rivet diameter
d ≈ (1.82.2)δmin = (1.82.2)•12 = 21.626.4 mm.
According to the table 1 choose d = 25 mm and d0 = 26 mm. Permissible voltages according to table. 2 subject to note:
metal [σр] = 160/2 = 80 MPa; rivets [σcm] = 320/2 = 160 MPa;
[τav] = 140/2 = 70 MPa, with drilled holes.
Number of rivets:
m ≥ F/(Aav[τav]m). Asp = mπd02 /4 = 1•3.14•262 /4;
m ≥ 250/(1•3.14•262/4)•70 = 7.9.
Crushing strength:
σcm = F/(Acmm) ≤ [σcm];
m ≥ F/(Asr[σcm]) = 250/(1•3.14•262 /4)•160 = 5.01.
We accept 8 rivets.
Basic parameters of a rivet seam: rivet pitch
t ≈ (36)d = (36)25 = 75150 mm;
with b = 350 mm, 3 rivets can be placed in a row with p = 115 mm;
distance from the edge of the sheet to the center of the rivet a ≈ (1.52)d = (1.52)25 = 37.550 mm;
the distance between staggered rows,
t ≈ (23)d0 = (23)26 = 5278 mm;
checking the joined sheets for tension in a dangerous section at m = 3
σр = F/(b – d0m)δmin = 250/(350 – 26•3)12 = 76.5 MPa ≤ [σр] = 80 MPa, which is acceptable.
2. Riveted structures
Riveted structures most often consist of the following types of parts: trusses made of rods working in tension or compression (longitudinal bending), beams and racks. For each of these types of parts, certain proven experience methods for calculating and designing rivet joints are used. The rods are connected at nodal points by means of gussets.
Compression rods are made from profiles with a small cross-sectional area and a large moment of inertia, i.e., from angles, I-beams, channels.
Depending on the location, solid rods are used, consisting of a T-beam, I-beam or channel profile.
Composite rods can be used from two profiles (angular, I-beam, tee or channel), connected by a continuous row of connecting rivets, as well as composite rods (Fig.
5), made of two or more solid rods, mutually connected by overlays or gussets. The truss rods must be connected in such a way that the lines of the centers of gravity of the rods intersect at one point of the gusset (Fig. 6).
Rice. 5. Composite truss bars
Rice. 6. Connecting profiles into a knot using a gusset, taking into account their centers of gravity
If the angle is connected by only one of its flanges, then 3 or 2 rivets must be used for the connection. Connection with only one rivet cannot be used.
Source: https://extxe.com/19474/zaklepochnye-soedinenija-detalej/
Threaded rivets: types, sizes, devices, how to install
A rivet is one of the most convenient and quickest fasteners to install, providing a reliable permanent connection. Today there is a huge variety of shapes and sizes of riveting fasteners, but hammer rivets were the first to be invented.
They were used in the construction of ships, bridges and other metal engineering structures, where they successfully replaced welded joints.
Today, this oldest type of fastener is made from modern materials, so it has not lost its popularity and has even expanded its scope of application.
What is riveting
The mechanical connection of parts using a series of rivets is called riveting, and the connection itself is called a riveted seam. It is used where it is inconvenient to weld parts or where non-weldable materials are joined.
Not only metals are riveted, but also parts in clothing, accessories, etc. are connected in this way. But there it is more of a finishing touch than a loaded connection. So next we will talk about riveting in construction or home improvement.
In principle, you can use a screw connection instead of riveting, but bolts and nuts are more expensive, and their installation takes longer.
This is what a rivet joint looks like
If we talk about installing fences made of corrugated sheets, rivets are more reliable, since they can only be removed by drilling out the fasteners. When installing screws or self-tapping screws, they can be unscrewed and both metal and hardware can be removed. In some cases, riveting is more convenient when installing a roof made of corrugated sheets or metal tiles. On the roof, installing screw connections is problematic and time consuming. But rivets, and with a good tool, can be done in an hour or even less.
Most common use in private households
How are parts connected using rivets? The rivet is installed in the prepared through hole. It has a head that rests on the material and the rod. During the riveting process, the end of the rod is flattened, changing shape under the influence of force. Therefore, ductile metals are used for these hardware.
Device of blind rivets
Structurally, the blind rivet is made in the form of a cylindrical rod with a semicircular or flat side. Also, the fastening element can be made in a hidden design, in which the head is hidden in a special recess in the base material. A single structure of fastening elements is obtained only by using a special tool, which allows obtaining a sufficiently large force to fasten the structural parts.
Types of rivet seams
If we talk about the method of joining sheets, then riveted seams can be overlapped (one sheet overlaps another) and end-to-end. Joint seams can have one or two overlays. With overlays they are more reliable and are used in critical and loaded places.
Types of rivet seams: overlapped and butted with overlays
According to the location of the rivets:
They can be located opposite each other or in a checkerboard pattern. Seams can be strong, tight (sealed) or durable-tight. Dense ones are made using elastic gaskets placed between the parts to be connected. Durable and dense ones are used mainly in boilers. Now they are more often replaced by welding.
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 to welding, for example, in explosive and fire hazardous facilities. Only they can cope with fastening parts in places where access for other types of connections is limited.
Types of rivet connections
Types of rivet joints. 4.67/5 (93.33%) lost 12
Riveted connections are non-separable or blind connections. In this case, the connection of two parts is carried out using a metal rod in the shape of a cylinder with a head at one end. This metal rod is called a rivet.
Based on the shape of the rivet heads, they are distinguished (Fig. 1):
- with semicircular;
- conical;
- cylindrical;
- secret;
- semi-secret head;
- barrel-shaped head and conical head.
Rice . 1 Types of rivets:
a, b - with a semicircular head; c - with a cone-shaped head; g - with a cylindrical head; d - with a conical countersunk head; e - with a semi-concealed head ; g - with a barrel-shaped head; h - with a barrel-shaped head and a cone-shaped head .
Read my other article: dimensions and weight of steel rivets according to GOST 10299-80.
Making riveted connections.
The riveting operation is as follows. A heated or cold rivet is inserted into the hole passing through the parts to be joined, one end of which protrudes slightly above the surface of the part. The rod protruding from the hole is pushed down by blows or pressure, and a second rivet head is formed. The first head of the rivet is called natural or embedded, and the second, formed during the riveting process, is called closing.
Materials for making rivets.
The material for rivets is soft, fine-fiber and fine-grained steel. Steel vessels and boilers are riveted with steel rivets, copper ones with copper rivets.
Manual and pneumatic riveting.
Manual riveting is carried out with special riveting hammers, pneumatic - with pneumatic riveting hammers. Machine riveting is performed using portable or permanent electric, hydraulic or pneumatic riveting machines.
The rivet inserted into the hole is supported from the side of the natural head by a fixed support, and the second end of the rod protruding beyond the surface of the part is pushed down by hammer blows or the pressure of the piston of the riveting machine.
The settling of the rivet rod ends with the formation of a closing head. First, several rivets are placed along the entire length of the rivet seam, in the spaces between the assembly bolts, and then the rest are placed, and only after that the assembly bolts are replaced with rivets. If riveting is carried out in order from one end of the seam to the other, then even due to small inaccuracies in the riveting, the holes will be displaced.
When assembling, sheets with punched holes have the widened part of the holes facing outward. With this arrangement, the rivet fills the hole better (Fig. 2).
Rice . 2 . Sheet connections:
a - correct; b - incorrect.
The diameter of the rivet is chosen so that the heated rod of the rivet fits tightly into the hole. To do this, the rivets are made of calibrated metal, and the hole is calibrated with reamers.
How to determine the length of the rivet shank?!
The length of the rod is determined by the formula:
l = δ + δ 1 + + δn + 1.5 d ,
Where:
δ—thickness of riveted sheets;
d is the diameter of the rivet.
The length 1.5d corresponds to the length of the rivet head with an addition for the shrinkage of the rod when filling the hole. The distance of the center of the rivet hole from the edge of the sheet to be riveted is sufficient to be 1.5 times the diameter of the rivet, but taking into account the strength requirements, we accept:
1.5d for sheets less than 20 mm thick;
1.5d + 5 mm for sheets with a thickness of 20-30 mm;
1.5d + 10 mm for sheets over 30 mm thick.
The distance between the centers of the rivets is taken to be up to 6d, but not less than 2d (Fig. 3).
Rice . 3 . Distance between rivet centers.
Ordinary and scattered riveting during installation work is the most difficult, since most often it occurs from the side and at a high altitude. Work is carried out from scaffolding and scaffolding, which restrict the worker’s movements. Also, when riveting some units, the number of rivets is limited and they are located at different heights and large distances from each other. All these conditions complicate riveting work.
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Source: https://mechanicinfo.ru/vidy-zaklepochnyx-soedinenij/
Rivets. How to calculate the required rivet length
A rivet is one of the simplest types of fasteners for creating permanent connections. In the general case, this is a rod or tubular part that has a supporting “embedded” head of a certain shape at one end. It is installed in the connection, as the name suggests, by the riveting method (as well as shrinkage, rolling, broaching, explosion).
Based on their shape, rivets can be divided into several main types:
- Rivets with a closing head (there are solid, hollow and semi-hollow)
- Rivets with broaches (also called tear-off or pull-out rivets)
- Threaded rivets (also called riveting nuts)
Rivets with locking head
Historically, rivets with a closing head were the first to be invented, which is why they became the most widespread. These rivets have a head on one side. The second head, called the closing head, is formed using a rolling or riveting tool: riveting hammer, pliers.
According to the shape of the head, rivets with a closing head are divided into:
- Round head rivets
- Countersunk rivets
- Rivets with semi-countersunk head
- Flat head rivets (with barrel)
They also differ structurally by the presence of a hole inside the rivet:
- Solid rivets - no hole
- Hollow rivets - tubular - have a through hole
- Semi-hollow rivets - for flaring - have a blind hole
Determining the length of the rivet
Correct installation of the rivet involves creating the full shape of the closing head and the absence of any excess gaps or sagging. To install the rivet correctly, it is necessary to determine the length of the rivet body, which depends on the thickness of the materials being riveted and the type of rivet.
“Handbook of mechanical engineering designer”, edited by Anuriev V.I. suggests using one universal formula for all rivet head shapes. Common sense suggests that this approach is erroneous - so we will use formulas from another source: “Fundamentals of Design”, edited by P.I. Orlov, 1988.
Rivet design | Allowance “H” for rivets without gap | Allowance “H” for rivets with a gap |
H=1.2d | H≈1.2d+0.1S | |
H=0.54d | H≈0.5d+0.1S | |
H=0.6d | H≈0.5d+0.1S | |
H=0.8d | H≈0.7d+0.1S | |
H=d | H≈0.9d+0.1S | |
H=1.2d | H≈1.1d+0.1S |
Having calculated the required allowance size using the formula, you can determine the length of the rivet L by the allowance value H to the thickness of the materials being riveted S. Then you need to select the closest rivet length from the standard range of lengths. A standard range of lengths has been approved for rivets, according to which they are produced (in mm):
- 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 45, 48, 50, 52, 55, 58, 60, 65, 70, 75, 80, 85, 90, 95, 100, 110, 120, 130, 140, 150, 160, 170, 180
Example of calculating the length of a rivet
For example, we need to rivet several sheets with a total thickness of 32 mm; We will rivet without gaps with rivets with a semicircular head Ø6 mm (1st design in the table).
d = 6 mm
S = 32 mm
H = 1.2d = 1.2 x 6 = 7.2 mm
Therefore, it is necessary to use a rivet with a shank length
L = S + H = 32 + 7.2 = 39.2 mm
We choose the closest length from the standard range - this is 40 mm.
As a result, we found out that to rivet a package of sheets with a thickness of 32 mm, we need a rivet of size Ø6x40 mm.
Source: https://kupit-bolty.ru/blog/zaklyopki-kak-rasschitat-trebuemuyu-dlinu-zaklyopki
Blind rivets choose length
· 09.09.2019
A rivet is one of the simplest types of fasteners for creating permanent connections. In the general case, this is a rod or tubular part that has a supporting “embedded” head of a certain shape at one end. It is installed in the connection, as the name suggests, by the riveting method (as well as shrinkage, rolling, broaching, explosion).
Based on their shape, rivets can be divided into several main types:
- Rivets with a closing head (there are solid, hollow and semi-hollow)
- Rivets with broaches (also called tear-off or pull-out rivets)
- Threaded rivets (also called riveting nuts)
What diameter are the rivets?
A rivet is one of the simplest types of fasteners for creating permanent connections. In the general case, this is a rod or tubular part that has a supporting “embedded” head of a certain shape at one end. It is installed in the connection, as the name suggests, by the riveting method (as well as shrinkage, rolling, broaching, explosion).
Based on their shape, rivets can be divided into several main types:
- Rivets with a closing head (there are solid, hollow and semi-hollow)
- Rivets with broaches (also called tear-off or pull-out rivets)
- Threaded rivets (also called riveting nuts)
Rivets with broach
Broached rivets are made hollow, with a head at one end; a movable expansion rod is inserted inside the rivet, which, when installed, is pulled through the rivet, expands it, forms a second closing head and tightens the sheets of material being fastened. After tightening, the rods break off or are pulled completely through the rivets.
Such rivets are often called tear-off or pull rivets - according to the installation technology. Broached rivets have become more and more popular lately. This happens for several reasons:
- technological ease of installation of rivets;
- it is enough to have access to installation from only one side of the structure;
- no rivet support required on the reverse side;
- cheap and compact tool for installing rivets;
- high productivity when setting rivets
- variety of rivet types
Since tear-off rivets are hollow, after installation there remains a hole inside the rivet into which you can route wires and install other fasteners - for example, screws. The diameter of the normal head of such rivets is approximately equal to two rivet diameters D ≈ 2d . Along with a normal head, rivets can have an enlarged head with a diameter equal to three rivet diameters D ≈ 3d.
A special type of water- and gas-tight rivets with broaching is also produced - blind or sealed rivets, after installation of which the connection becomes airtight.
Installation of rivets with a broach is carried out using a special tool - a rivet gun - a riveter. We produce mechanical manual riveters and high-performance pneumatic and battery electric riveters.
A schematic diagram of installing a rivet with a broach is shown in the video:
Materials for broach rivets
Based on the method of installing rivets with a broach, it seems logical that the rivet assembly consists of two materials, and the material of the rod must be stronger than the material of the rivet itself - otherwise the rod will open and compress the rivet before it collapses. Such rivets use either a couple of different materials or the same type of materials, but with different strengths. Here are the most common pairs of materials for broach rivets:
- Aluminum rivet + galvanized steel rod (in fact, the rivet is not made of aluminum, but of aluminum-magnesium alloy AMg , which can have different percentages of magnesium (Mg): 1%; 2.5%; 3.5%; 5% - respectively, alloys AMg, AMg2, AMg3, AMg5 - the higher the magnesium (Mg) content, the stronger the rivet) - denoted Al/St
- Painted aluminum rivet + galvanized steel rod (the rivet is made of aluminum-magnesium alloy AMG , and the outside is powder-painted in a specific color from the RAL ) - denoted Al/St 0000 , where 0000 the RAL color chart
- Aluminum rivet + aluminum rod (rivet and rod are made of aluminum-magnesium alloys AMG, but with different percentages of magnesium - the rod is stronger) - denote Al/Al
- Aluminum rivet + stainless steel rod - denoted Al/A2
- Stainless rivet + stainless rod (both the rivet and the rod are made of stainless steel, but of different grades, and the rod is stronger) - designated A2/A2 or A4/A4
- Copper rivet + galvanized steel rod - denoted Cu/St
- Copper rivet + bronze rod - denotes Cu/Br
- Copper rivet + stainless steel rod - denotes Cu/A2
- Galvanized steel rivet + galvanized steel rod (rivet and rod made of steel, but of different grades and the rod is stronger) - denoted St/St
Determining the length of a rivet with a broach
The length of the rivet with a broach can be determined using the following table, depending on the thickness of the materials being fastened (the manufacturer strongly does not recommend using rivets for riveting materials with a thickness less than the lower recommended limit and higher than the upper limit).
Source: https://master-kleit.ru/origami/kakogo-diametra-byvajut-zaklepki/