How to read a weld

Designation of welds in drawings: table, explanation of documentation

If you say that GOST is your favorite word, hardly anyone will believe you.
But if you are engaged in welding and claim to be a high-class professional, you will have to treat this word with all respect, if not love it. You need to not only respect him, but also have a good understanding of the required state standards regarding the typology of welding methods.

Why? Because if you are working with something more serious than an old basin at the dacha, you will definitely come across working drawings with huge quantities of icons, letters and abbreviations.

That's right, without technical specifications and standard designations - nowhere. Modern welding technologies are a wide range of very different methods with their own requirements and technical nuances.

All of them fit into several standards, which we will now go through and consider in the most careful manner.

Welding designations on GOST drawings look intimidating at first glance. But if you figure it out and stock up on the original versions of the three main GOSTs on the types and designations of welding technologies, the designations will become clear and informative, and your work will be accurate and professional.

Documentation for welded structures

A special type of assembly models are welded structures, the creation process of which consists of “cutting”, “welding”, “processing” and “modelling”. For any of the states, specific views can be created in the drawing:

• Assembly state views allow you to see what the model looks like without welded joints or the required cutting;
• types of preparation represent a model with an already specified cutting of connecting seams;
• types of welding show the future model with welded joints;
• types of processing determine the model with preparation of joints, with ready-made joints and processing after welding.

When designing drawings, only the assembly state can be applied. When the structure goes into any of the other states, an appropriate message about this should be provided.

The principle of choosing a welding method and type of connection

About 150 types of welding are used to join parts. One thing they have in common is the designation of seams in welded joints. Any development involves carrying out calculations established by the technical specifications for it. To determine the method of fastening parts, designers perform calculations that determine the geometry of the joints and the thickness of the structures being welded.

Calculations allow you to determine the type of welding that should be used: manual using electrodes, arc with shielding gases, etc. In your work, you must be guided by the requirements of standards containing the necessary information.

What are the types of welds?

Modern types of welding open up a huge number of possibilities for the master, allowing him to translate any ideas into reality. But in order to put any welding technology into practice, you need to understand the designation of welding and learn how to draw up drawings.

Depending on the technology, the welding symbol in the drawings is as follows:

• E - electric arc;
• Kt - contact;
• G - gas;
• Z - performed in a protective gas environment.

The drawings contain all the information that a craftsman may need in the process of welding metal structures, so a prerequisite for every professional welder is the ability to read and draw up welding drawings.

Types of welding joints and symbols

To ensure high-quality connection of individual elements when creating metal structures, it is necessary to have a detailed description of each joint. To do this, design documentation consisting of drawings is carried out, in which all symbols of welds must comply with GOSTs.

Depending on the methods of joining the elements welded to each other, several types of connections are distinguished. The names, features and designations of welding seams in the drawings can be found in the table below.

Types of seams	Characteristics	Welding seam on the drawing
Butt	Parts located in the same plane are welded at adjacent ends. In order for the joints to be smooth and strong, it is necessary to process the butt edges before joining.	WITH
Angular	The parts are connected along ends inclined to one another, the angle between which should be more than 30°	U
Tortsevoy	The ends of the elements are connected so that the side surfaces touch each other	WITH
Lap	The planes of the elements are superimposed on one another. Used in cases where the accuracy of the fit is not critical	N
Tavrovy	The end of the part is welded to the surface of the structure at an angle or vertically	T

There are also special types of seams not provided for by GOST, which are indicated in the diagrams by the symbol “O”.

Non-standard connections

The given structure refers to the designation of standard welds, that is, those that are performed in accordance with GOST. To display in the drawing welded joints that are not made in accordance with GOST standards, a similar structure is used, only shortened, consisting of a main block and two additional ones.

The main block, as in the previous structure, contains graphic symbols indicating the nature of the connection. The information contained in 1 - 4 additional blocks of the standard structure is not available here, since the non-standard welding seam is not performed in accordance with GOST.

Therefore, the first additional block of the non-standard seam structure contains parameters that clarify the specific features of this connection. The second block contains special information, the need for which is determined by the designer.

All technological features of performing non-standard welding processes, including the type of welding used, a special mode of work, additional means used, are described in detail separately, in the technical requirements supplementing the project drawings.

Necessity of notation

Modern metal structures consist of many elements of different shapes and sizes. In order for them to meet all the requirements of GOSTs, they must be created according to previously developed design documentation.

Source: https://instanko.ru/osnastka/oboznachenie-svarnyh-shvov-na-chertezhah.html

Rules for designating seams in drawings according to GOST

Welding is the most popular method of joining different types of metals. If home work does not have strict requirements for the type and correctness of connections, then industrial work is carried out under control at all stages - from checking design documentation to non-destructive testing methods of the finished connection.

Even 20 years ago, only technologists and work managers could read welding drawings, but the rapid development of technology has led to the fact that the circle of people with this skill has expanded significantly.

Correct designation of welds on the drawings is the key to high-quality work. A qualified welder must be able to read design documentation and have knowledge of the symbols in them.

What is a welded joint?

The process of permanent connection is accompanied by high-temperature effects on the surface of individual elements. The place where the seam is formed is called a weld joint .

Types of seams and their interpretation

The designation of the weld seam in the drawing and their interpretation depends on the type of connection. The main connection methods include:

1. Butt weld . Characterized by end joining of parts. If necessary, preliminary preparation of the edges can be done. In the drawings it is designated by the letter “ C ”.
2. Overlap seam . This type involves parallel joining of elements with partial overlap relative to the welding plane. Designated " N ".
3. T-seam . In this case, the end part of the second workpiece is welded to the plane of one part at a certain angle. In technical documentation it is marked as “ T ”.

1. Corner . As the name suggests, parts are welded at an angle of 90º, with or without preliminary edge preparation. Denoted by the letter " U ".
2. Tortsova . This method connects elements in a coaxial arrangement. In this case, the end part is the zone for surfacing the filler material.

Surfacing can only be done on one side. In this case, the seam is called one-sided. A two-way connection involves welding on both sides.

Necessity of designation

All modern building and industrial structures consist of many elements. The reliability and service life of the facility depend on the quality of installation. Welding designation on drawings in accordance with GOST is the main requirement for any design documentation .

After studying the drawing, an experienced specialist will receive the following information:

1. Materials used.
2. Preliminary preparation and necessary approvals.
3. The joining method and its geometric parameters.
4. The strength of the seam and its quality characteristics.
5. Shape and size of surfacing mixture.
6. Tightness of the connection.
7. Installation sequence.
8. The nature of the surface finishing.

Illustration of welds in the drawing

To standardize welding, the ESKD system has been developed - a unified system of design documentation , which specifies all possible designations, as well as requirements for the preparation of regulatory documentation. This system provides for the interaction of all participants in the technological process. The number of the interstate standard containing the basic requirements for graphic symbols is 2.312-72.

According to the requirements of this standard, all welding joints are depicted as follows:

1. External seam . Indicated by a solid line of the main type. It is necessary to have an extension line with an arrow that points to the seam.
2. Multi-pass connection . In this case, the image should contain contours of the contact area with special symbols.

1. Non-standard seams . The document contains all the information necessary for the quality of the work.

The extension line shows not only the location of the future connection. Using auxiliary signs, the following information is specified:

• the nature of the seam;
• type of processing;
• installation requirements;

At the same time, there are no requirements for the welding equipment used - it can be either a manual arc welding machine or an automatic contact line system.

https://www.youtube.com/watch?v=qBf24cIxYuU

The order of arrangement of information on the leader is as follows:

1. Closed line information.
2. Interstate standard number.
3. The serial number of the connection.
4. Work execution technology.
5. Seam leg.
6. Size of spot welds.
7. Additional designations.

After the second position, information is separated by a hyphen.

Auxiliary signs

The following information is indicated using auxiliary signs:

1. The requirement to eliminate the convexity of the seam after work.
2. It is necessary to ensure a smooth transition to the base plane by manually or mechanically processing all irregularities.
3. Welding is performed along an open line.
4. The joint must have a closed loop.
5. Welding work is carried out after installation of the workpiece.
6. Type of seam - intermittent or spot, with a chain arrangement.
7. The connection is made in a checkerboard pattern.

The weld designation options and work requirements are marked as follows:

1. " A ". The work is carried out using automatic installation under a layer of flux, without preliminary welding of the joint. There should be no lining or cushion.
2. " Af ." Automatic submerged arc welding using a special lining based on it.
3. " IN ". The work is carried out using a refractory electrode in a protective gas environment. We are talking about tungsten materials here. In this case, no additional filler material is used.
4. " INP ". Gas shielded welding using filler materials.
5. " IP ". Welding with electrode wire in a shielding gas environment.
6. " UP ". Work in a protective gas environment, which is carbon dioxide.
7. " G " Gas welding technology.
8. " E " Electric arc welding.
9. “ Z ” Work should be performed in a protective gas environment.

Technical abbreviation

Studying the designations of connection types on drawings in accordance with GOSTs is the responsibility of every welder who wants to reach the level of a professional. To obtain the much-needed skill, there are two working methods:

1. Study all interstate standards that are related to design and technical documentation. In addition to GOST 2.312-72, which was discussed above, there are two more standards: 5264-80 and 14771-76.

1. Consider the presentation of information using the example of finished drawings. This will help you gradually deepen your knowledge, with the necessary speed and intensity. An additional advantage of this method is that the documentation will contain only the information that the welder needs.

Symbols of connections. Examples

Let's use the following drawing as an example:

Explanation:

1. The first symbol indicates that welding work should be carried out after installation of the workpieces.
2. The interstate standard number indicates that in this case manual arc welding is used.
3. C 13. Butt type of connection with one-sided bevel bending.
4. The next symbol requires eliminating the convexity of the seam after the work. The sign located under the extension line indicates that processing should be carried out on both sides.
5. Rz20. Required roughness of the outer part. This parameter corresponds to class 3 surface cleanliness, according to GOST 2789-59.
6. Rz80. Required back side roughness. This parameter corresponds to class 1 surface cleanliness, according to GOST 2789-59.

Designation structure

Welding in the drawing is indicated as follows:

The location of the clarifying inscription indicates the type of connection:

1. Above . Indicates the facial location of the seam.
2. Below . Welding is done from the reverse side.
3. On both sides . In this case, double-sided welding is used.

Let's consider the structure of the location of markings:

1. The first column indicates the contour of the seam closure, as well as the installation conditions for the connection.
2. Number of the interstate standard according to which the work is performed.
3. Serial number according to design and technical documentation. Contains both letters and numbers.
4. A hyphen that must be used to separate all subsequent positions.
5. The technology for making the connection is indicated here (using electric arc or gas welding, in a protective gas environment and under a layer of flux). This position is not mandatory.
6. The size of the angular leg. Indicated in millimeters.
7. Intermittent seam size.
8. Location of auxiliary symbols.
9. Surface cleanliness class, if treatment is necessary.

Simplifications

For the manufacture of even the simplest design, it is necessary to prepare the appropriate documentation. If all the seams in the drawing are made according to the same standard, the information is included in the explanatory note.

https://www.youtube.com/watch?v=8KPusauj5NE

In addition, other simplifications are allowed, according to the recommendations of GOST 2.312-72:

1. If all the seams in the drawing do not differ in type and are located on the same side, they are not assigned a serial number. They are indicated by leader lines without shelves.
2. When making a symmetrical part, it is allowed to mark seams on only one of its sides.

1. Some drawings contain several identical elements that are welded using the same method. In this case, a leader line is allowed to mark only one of the component parts. It is important that the designated element has a serial number.
2. In some cases, it is allowed to replace the extension line with an indication in the explanatory note to the drawing. This is permitted provided that the location of the seam is accurately determined, as well as its technical and quality characteristics are indicated.

Using CAD

Currently, all drawings are performed using special software . Developers offer many products, among which the following software packages have gained the most popularity:

• AutoCAD;

Source: https://svarka.guru/sertifikatsiya-i-obuchenie/pravila-oboznacheniya-shvov-na-chertezhah-po-gostu.html

Symbol of a weld on drawings according to GOST

Welding as a technological process has been known since ancient times, more precisely from the moment our ancestors learned to work with iron. Today we can count about 150 types of welding processes. But they are all united by one thing - designation.

When developing a product, a design engineer uses a lot of reference and regulatory documentation in his work. But when documenting the results of his work, he must be guided by the requirements of the ESKD (unified system of design documentation).

This is a set of standards that regulate the preparation of documents - drawings, specifications, technical specifications, etc. If all working documents are made in accordance with the requirements of regulatory documentation, all thread, welding, etc. symbols will be indicated.

, then it will be difficult to allow defects in the manufacture of the part.

General principles

The ESKD includes GOST 2.312-72, “Conventional images and designations of seams of welded joints.”

On its pages, the design engineer will find all the necessary information and it will not be difficult to show the welding symbol in the working documentation.

Indeed, there is nothing complicated in designating seams in the drawings, especially if you follow the requirements described in the specified GOST.

For detailed designation of seams in the drawing, a leader line with a shelf is used, on which the seam parameters, conditions for additional processing, etc. are indicated.

The visible part of the welding joint in the drawing is conventionally depicted using the main line, the invisible part is shown with a dashed line.

If the joint is made in several passes, then in the section it is permissible to show each layer as a separate contour. Moreover, each of them must be assigned a letter designation. Thus, when reading the drawing, it will become clear that layer A is applied first, layer B second, and so on.

We recommend! What and how to weld aluminum

The principle of choosing the type of seam and welding method

The basis of any development is a set of certain calculations defined in the technical specifications for the development. That is, when choosing the type of joint and the method of obtaining it, the designer must carry out all the necessary strength and force calculations, which should determine the thickness of the metal being welded and the geometric parameters of the joint.

As a result of the calculations, the welding method will be determined, for example, gas-shielded arc welding or traditional manual welding using electrodes. Depending on this, the designer must refer to GOST, which contains all the necessary information.

Every designer knows that domestic GOSTs define five types of seams:

butt – C;

overlap - N;

T-bars - T;

corner – U;

end

Each of these joints can be used depending on the requirements for the design of the resulting unit. Read more about the types and types of welds and connections here.

In addition to the letter designations indicated in brackets, there are additional (auxiliary) signs that are designed to ensure completeness of information about the weld.

Additional (auxiliary) signs

GOST 5264-80 and GOST 14771-76 show the main types of welded joints, their designation and permissible dimensions. For example, a T-weld made from sheet steel with a thickness of 8 - 100 mm has a weld designation in the drawing - T8.

Shape of prepared edges

Cross-sectional shape Thickness of welded parts, mm

Symbol of welded joint

Prepared edges Completed seam With a curved bevel of one edge 15 – 100 Т2 With two symmetrical bevels of one edge 8 – 100 Т8 12 – 100 Т9

The same documents indicate mandatory dimensions, for example, the leg of a seam. Its parameters are selected based on the size of the yield strength. So, if the yield strength has not reached 400 MPa, then with a thickness of the welded parts from 22 to 32 mm, the weld leg should be 8 mm. When using standard weld sizes, there is no need to indicate its dimensions on the drawings.

If the designer has decided to use a non-standard seam, then its dimensions must be indicated in full

Full seam designation on the drawings

Standard seam designation structure

In the numbered cells, the designer must indicate the main characteristics of the seam.

So, in the first cell it is necessary to show additional signs shown in the figure. In the second, the designer prescribes GOST for the welding method. The third should contain the designation of the seam, for example, T4. Next, the size of the seam leg must be indicated. This designation indicates the parameters of the intermittent seam and other auxiliary signs.

The data placed on the drawings serve as the basis for control of finished products. That is, an employee of the technical control department, guided by the requirements of working documentation and technical specifications, must carry out the appropriate measurements. Let's say he can check the leg size using a traditional measuring tool. The quality of welding can be checked using technical control tools, such as ultrasound.

If a product uses many joints of the same type, the designer has the right to draw up a table of parts connections indicating the welding parameters and seam number.

Using CAD in the work of a designer

Source: https://svarkagid.ru/tehnologii/kak-oboznachaetsya-svarka-na-chertezhah.html

Weld seam: designation, GOST:

Few construction projects are complete without the use of welding; it is used in the construction of various types of buildings and structures, from offices to skyscraper houses. With its help, several components are connected into one whole. During operation, a weld is formed. It ensures reliability and strength of the connection. The seam can last a long time if it is not damaged by any mechanical forces.

General information

A weld is capable of connecting various metal parts made not only of homogeneous material, but also of alloys. However, to perform this process it is necessary to select a certain welding technology and consumables. The worker who will connect the parts must be highly qualified and experienced. It takes into account the characteristics of the metal and connects it in such a way that when a load is applied to it, it does not collapse.

Letter markings

The designation of welds, as well as their types and places of application are indicated in the regulatory documentation. This information is used for various technical documentation. It is indicated in special training manuals that are used when training welders or improving their qualifications. GOST 5264-80 describing welds is the main guiding document. That is, all the information for teaching aids is taken from it.

You can determine the type of connection without looking at the documentation. The designation of welds on drawings anywhere in a building structure is carried out using letter markings. So, these types of welded joints are distinguished by letter designations:

• “C” - butt;
• “N” - overlap;
• "T" - T-bar;
• "U" is angular.

Types of seams

The weld is classified according to several criteria. So, according to the type of final cross section they are divided into:

• butt - when connecting, metal parts must be in the same plane;
• angular - products must be at a certain angle to each other;
• slotted - when welding, metal parts lie on top of each other. In this case, the upper product melts completely, and the lower one partially.

The next indicator is configuration. Welds (GOST 5264-80) can be straight, curved or circular.

Welding can be done in several ways. It is worth noting the application with a continuous seam or intermittently. In the first case, the weld can have a length of 300 mm or more. The second option is performed in extreme cases, since the seams are made in a checkerboard pattern. The connection also depends on the operating technology. Welding is performed both with and without additional gas.

When performing construction work, the seam can be performed a different number of times. That is, it can be single- or multi-layer. This is done to strengthen the connection and increase its strength characteristics. During the process, additional weld deposits may form on the connection. According to this indicator, seams are classified into normal, reinforced and weakened.

As a rule, such connections are not separated. They can be performed in various ways and combine several types of work. This depends on the qualifications of the welder, as well as the quality of consumables.

Connection Features

The quality of welds depends on the chosen technology, as well as the qualifications of the worker. Metal parts are attached to each other through a melting process. When using arc welding, they must be located in the same plane.

Such parts can have different shapes and edge conditions. The latter is processed depending on the thickness of the elements. When connecting products with different thicknesses, it is necessary to adjust the large sheet to the smaller one. In this case, the seam will be reliable.

In accordance with this characteristic, according to the type of edges, welded joints are:

• with a skewed edge (the seam thickness should be 5 mm);
• with curvilinear;
• U-shaped edge. In this case, the thickness of the seam should be from 20 to 60 mm;
• X-shaped edge (seam thickness should be from 12 to 40 mm).

Connection characteristics

One of the main positive properties of welded joints is low voltage. This means that they are not subject to bending and destruction. That is why this type of connection is often used. In addition, the process consumes a minimal amount of metal. To perform high-quality welding, it is necessary to carefully carry out the preparatory stage. Let us consider in detail the characteristics of different types of compounds.

To obtain a T-joint, you need to fasten two parts that will be perpendicular to each other. The designation of welds in drawings of this type is represented by the letter T.

Welds can be located not only on one side, but also on the other.

It all depends on where it will be used and what requirements are placed on it. This type is used to construct various columns and frames.

If significant loads will not be placed on a certain place, an angular type of connection is used. Most often it is used in the manufacture of various containers.

In this case, the following requirement must be met: in order for the structure to last longer, the thickness of the metal should not exceed 3 mm. To make such a connection, one part is applied at a certain angle to the other and welded on both sides.

This is done to prevent moisture from entering and destroying the structure. The weld seam in the drawing is designated by the letter U.

The last type of connection is an overlap connection, where the parts are attached perpendicular to each other. The seam is formed on the side of the structure. In addition to this procedure, it is necessary to secure the connection by fusing. This consumes a significant amount of metal. In this case, the thickness of the structure should not exceed 12 cm. To prevent moisture from getting inside the product, the metal is fused on both sides. The designation of welds of this type is indicated on the drawings with the letter “H”.

When making any seam, the spot welding method is used. The exception is when fusing is required. Then the seam is made in a round shape.

Additional indicators

Arc welding can be performed by two methods: manual and mechanized. It all depends on the thickness of the metal. With the manual method, elements with a thickness of no more than 4 mm are welded, and with the mechanized method - 18 mm. Parts of large thickness can also be processed manually. But it is necessary to additionally process the edge.

Gaps may form between two welded elements, as well as deviations of parts at a certain angle, that is, a bevel and groove angle is formed. To make a quality seam, you must correctly determine the bevel angle. This indicator indicates the availability of the arc. Depending on the type of connection, the indicators of this angle range from 20 to 60 degrees, including the minimum error.

Burns

Burn-throughs may occur during the welding process. The main reason is the unblutted edge. Welding is not possible if the distance between two metal parts is too large.

To choose a method for making a seam, you need to decide on the material, as well as the degree of complexity. During the construction of any building, documentation is drawn up. It is in it that information about the material costs of processing metal parts should be entered. Symbols of welds are indicated in the corresponding drawings. They can be seen in the photo below.

As you can see, the shade of the part is significantly different, and the thickness of the seam (joint) itself is twice as thin as the others.

Weld inspection

Their quality can be controlled by many methods and methods. So, the methods used are as follows:

• mechanical;
• chemical;
• physical;
• visual inspection.

The most common is external inspection of the finished connection. This is the easiest and most affordable method that does not require material costs. Any welded joint is subject to external inspection, regardless of further operations. But you can perform other checks.

With the help of an external inspection, many visible defects that arose during the work are determined. Thanks to him, various lack of penetration and influxes are found. Visually they are practically invisible.

To identify them, you need to use a special magnifying glass that magnifies the surface ten times.

During this operation, not only visible defects are determined, but also they check and measure pre-prepared edges. For mass production of welded joints, special templates were developed. They allow you to measure a seam in a short period of time. Other methods require financial investments in individual substances and equipment.

Conclusion

So, we found out what a weld is. The requirements for it are quite high, since it is he who is responsible for the reliable connection of metal structures.

Source: https://www.syl.ru/article/243214/new_svarnoy-shov-oboznachenie-gost

Designation of welds on drawings

Iron is widely used in construction and manufacturing. A welding joint is used for connection; today it is possible to perform up to 150 types of work. To ensure proper execution of the design, before starting work, use the drawings included in the design documentation system. The regulations define the basic requirements for the design of welded joints.

Designation of welds on drawings

What is a welded joint

The process of welding a product involves the closure of parts due to temperature effects. The melting of metal in a certain area, and then the place where it solidifies is called a weld.

Welded joint

There is a variety of welds, marked by GOST in accordance with the standard of welding drawings.

1. The butt joint is marked with the letter “C”, a union of the end surfaces of the product is formed, and the edges are processed.
2. The overlap method is used when parts may overlap each other and is marked as “N”.
3. The parts to be joined are arranged in planes relative to each other at an angle, designated “U” in the technical documentation.
4. End welds are used by overlapping a layer of metal to the ends of the products.

The work is carried out both unilaterally and bilaterally, when the part is processed on both sides. The quality of joining by welding affects the service life of the part used. Weld joint symbols contain detailed information about the parameters of width, convexity, etc.

The length is indicated as a continuous, discontinuous connection. A weld made intermittently does not provide complete tightness of the structure, but is performed for hard-to-reach connections. A seam along an open line is indicated as an additional condition in the drawings and is used when clearly positioned on the diagram.

The need to define welding

Geometric parameters and the shape of the seam are noted to determine the type of structure in the drawings. The method of welding affects the characteristics of the product, its tightness and strength. Before producing butt joints, it is necessary to study all the necessary parameters according to the project.

Welding is designated according to the main parameters:

• Dimensions and shape of welded metal.
• The type of joint is indicated by intermittent or continuous, thermal stresses formed in the joint area.
• The tightness of the welded splice is determined by the purpose and type of construction.

The execution of the product is controlled by the quality department, in accordance with the parameters. Measurements of finished products occur in accordance with the technical conditions and designations of welds on the drawings.

GOST standards

GOST standards refer to the type and parameters of the welded joint in the drawing. Used in all types of industry and construction as a single standard for designation. GOST 2.312-72 indicates the type of products produced by the butt method, regardless of the scope of application. For a correct process, you need to remember the basic expressions of the instructions.

Scheme for designating welds in drawings according to GOST

Possible simplifications or reductions are prohibited, but occur in certain cases:

• A project containing the design of parameters according to one standard may contain a table and names of connection points.
• Designation with lines without leaders or shelves is possible in cases where the position of the part is identically displayed in the drawing (front or back side).
• If the displayed product is symmetrical, it is allowed to mark the seams of only one part.
• In the technical requirements, it is possible to indicate a record for determining places and methods of welding, as well as a statement of the same requirements.

Download GOST 2.312-72

Examples and explanation of seams in the drawing

To fully understand how to work with joints according to the drawing, it is necessary to consider several examples.

T-type connection

T-type connection, staggered according to GOST 14806-80. Welding method – arc, manual in shielding gases with a metal electrode. The length of the welded area should be 50 cm, the pitch should be 100 mm, the seam length should be 6 mm.

One-way lap joint

A one-sided overlapping joint, without beveling the frames in accordance with GOST 14806-80, is performed by semi-automatic arc welding using shielding gases and a consumable electrode. Indicated work on a closed line, leg 5 mm. In cases where the project specifies the same names, it is not necessary to describe each side; it is enough to use the information on one side.

Cross section of the joint

a) Indicating the front side with an arrow

b) Reverse side

One-sided tie of a butt joint without the use of beveled edges, gasket.
According to GOST 16310-80, it is performed with heated gas with additives. The front side has an indication of the junction with the front part with a continuous line, for a more understandable operating mode. Today, a designer’s work includes a lot of software products and tools. Using programs for drawing welded screeds allows you to reduce development time by automating the process.

Source: https://stankiexpert.ru/spravochnik/svarka/oboznachenie-svarnykh-shvov-na-chertezhakh.html

Reading the designations of welds in the drawings

Modern types of welding open up many possibilities for the master, allowing professionals and amateurs to realize their ideas. Using argon arc welding, you can join dissimilar metals, and using a budget inverter, you can weld a fence in your dacha.

But sometimes welding equipment and components for them are not enough for full-fledged work; it is important to learn how to make and understand welding drawings.

In them you can find out all the comprehensive information about the metal that needs to be welded, its thickness, characteristics and locations of future joints.

A drawing is a full-fledged document issued for one specific part or an entire metal structure. It contains all the information a welder might need. Reading welding blueprints proficiently is a must-have skill for any welder looking to build a career in the profession. In our article you will learn what is needed to decipher seams in drawings and what signs are used for this, we will also give several examples.

Examples of symbols

To make it clearer for you and you can quickly understand all the notations, we will give several simple and illustrative examples. So, let's begin.

Example No. 1

In the picture above you see a butt seam in which one edge has a curved bevel. The connection itself is double-sided, made by manual arc welding. There is no gain on either side. On the front side the seam roughness is Rz 20 µm, and on the back side it is Rz 80 µm.

Example No. 2

Here you can see that the seam is corner and double-sided, it has no bevels or edges. This connection is made by automatic welding and using flux.

Example No. 3

Here we have a butt seam again, but without bevels or edges. The connection is one-sided, with a lining. The seam is made using heated gas and welding wire.

Example No. 4

In the fourth example, the seam is a T-joint and has no bevels or edges. It is intermittent and performed using a bilateral method. The seam seems to be in a checkerboard pattern. The work was performed using RDS in a gas environment and using a non-consumable metal rod. The leg of the seam is 6 millimeters, and the length of the seam is 50 millimeters, in increments of 100 millimeters (indicated by the letter “Z”). t w is the length of the seam, and t pr is the length of the step of the intermittent connection.

Example No. 5

In our last example, the seam is overlapped and has no bevels or edges. It is also single-sided and is performed by manual gas-shielded arc welding using a consumable rod. The welded connection is made along an open line. The leg of the seam is 5 millimeters.

Instead of a conclusion

That's all we wanted to tell you about the symbols of welding seams. We hope that now you know how to read symbols on drawings. At first, it is difficult for beginners to remember all the signs and letters used as symbols for welding seams. Therefore, do not be afraid to use a notebook with the abstracts written out from this article in your work.

With experience, you will learn to decipher all the signs and be able to read even the most intricate drawings fairly quickly. And in a large production, a folder with drawings can be quite voluminous, so it is important to be able to quickly and accurately read all the documents for a metal structure. Experienced craftsmen can share their experience of reading drawings in the comments to make it easier for novice welders to understand all the nuances and features. We wish you good luck in your work!

Source: https://svarkaed.ru/svarka/shvy-i-soedineniya/chitaem-oboznacheniya-svarnyh-shvov-na-chertezhah.html

GOST standards

The main GOST for designations is 2317-72 - Conventional images and designations of welds. Besides this there is also:

• 21.502-2007 – Rules for the execution of design documentation for the creation of metal structures;
• Designation of welds in drawings GOST 5264-80 – Manual electric arc welding, as well as welded joints.
• Designation of welds in the drawings GOST 14771-76 - Arc welding in a shielding gas environment, as well as welded joints.

Auxiliary signs

Drawings often contain special auxiliary symbols that help briefly indicate the required information. There are not so many of them and all of them, along with the decoding of the meaning, are given below:

№	Image of the auxiliary sign	Information about this sign	Where should the given auxiliary symbol be located on the leader line?
Top of the line	Bottom of the line
1	Seam reinforcement needs to be removed
2	Existing irregularities and sagging must be processed to create a smooth transition from the weld bead to the base metal
3	The seam must be made during installation of the product, that is, during installation everything is done at the place of use
4	Creating a spot or interrupted seam with a chain seam arrangement. The tilt angle should be 60 degrees
5	Create a spot or interrupted seam with a staggered seam pattern.
6	Creating a seam along a closed line. The diameter of such a sign in the drawing is from 3 to 5 mm.
7	Creating a seam along an open line. This sign is used if the location of the welded joint is clear from the drawing.

Source: https://svarkaipayka.ru/tehnologia/drugoe/oboznachenie-svarnykh-shvov-na-chertezhakh.html

Welding designation in drawings according to GOST: examples and table explanation

If you say that GOST is your favorite word, hardly anyone will believe you. But if you are engaged in welding and claim to be a high-class professional, you will have to treat this word with all respect, if not love it.

You need to not only respect him, but also have a good understanding of the required state standards regarding the typology of welding methods. Why? Because if you are working with something more serious than an old basin at the dacha, you will definitely come across working drawings with huge quantities of icons, letters and abbreviations.

That's right, without technical specifications and standard designations - nowhere. Modern welding technologies are a wide range of very different methods with their own requirements and technical nuances. All of them fit into several standards, which we will now go through and consider in the most careful manner.

Welding designations on GOST drawings look intimidating at first glance. But if you figure it out and stock up on the original versions of the three main GOSTs on the types and designations of welding technologies, the designations will become clear and informative, and your work will be accurate and professional.

Types of welding seams

First, ESKD is the Unified System of Design Documentation, or, to put it simply, a set of various standards according to which all modern technical drawings, including documentation for welding work, must be carried out.

This system contains several standards that interest us:

1. GOST 2.312-72 entitled “Conventional images and designations of seams of welded joints”.
2. GOST 5264-80 “Manual arc welding. Welded joints”, which comprehensively describes all possible types and designations of welds.
3. GOST 14771-76 “Seams of welded joints, welding in shielding gases.”

To understand the symbols of welding methods in engineering drawings, you need to understand their types. We suggest looking at an example of a weld designation in the drawing:

It looks bulky and intimidating. But we won’t be nervous and will slowly figure it out. There is a clear logic in this long abbreviation, let's start moving step by step. Let's break this monster down into nine parts:

Now these same components in squares:

• Square 1 – auxiliary signs to indicate: a closed line or an installation connection.
• Square 2 is the standard by which the symbols are given.
• Square 3 – designation by letter and number of the type of connection with its structural elements.
• Square 4 – welding method according to the standard.
• Square 5 – type and dimensions of structural elements according to the standard.
• Square 6 – characteristic in the form of the length of a continuous section.
• Square 7 – characteristics of the connection, auxiliary sign.
• Square 8 is an auxiliary sign for describing a connection or its elements.

Now let’s look at each element of our long abbreviation in detail.

In square No. 1 there is a circle - one of the additional characteristics, a symbol of a circular connection. An alternative symbol is a flag, indicating a mounting option instead of a circular one.

A special one-way arrow shows the suture line. Another specific feature of welding drawings is associated with this arrow. This single-faced arrow has a nice feature called a shelf. The shelf plays the role of a real shelf - all symbols can be located on the shelf if a visible connection is indicated.

Or under the shelf, if the seam is invisible and located on the reverse side, i.e. from the inside out. What is considered the front side and what is the back side? The front side of a one-way connection is always the one that is being worked on, it's simple. But in the double-sided version with asymmetrical edges, the front side will be the one where the main joint is welded. And if the edges are symmetrical front and back, any side can be used.

Here are the most popular auxiliary signs used in welding drawings:

We disassemble squares No. 2 and 3, types of seams according to GOST standards

Two standards closely deal with connection options: the already familiar GOST 14771-76 and the famous GOST 5264-80 on manual arc welding.

An example of a drawing of welds according to GOST.

The types of welding joints are as follows:

C – butt seam. The metal surfaces to be welded are connected by adjacent ends, located on the same surface or in the same plane. This is one of the most common options, since the mechanical parameters of butt structures are very high. At the same time, this method is quite complex from a technical point of view; experienced craftsmen can do it.

T – T-seam. The surface of one metal workpiece is connected to the end of another workpiece. This is the most rigid design of all possible, but due to this, the T-bar method does not like and is not intended for bending loads.

N – lap seam. The surfaces to be welded are parallel offset and slightly overlap each other. The method is quite durable. But it carries less load than the butt options.

U – fillet weld. Melting occurs at the ends of the workpieces; the surfaces of the parts are kept at an angle to each other.

O – special types. If the method is not in GOST, a special type of welding is indicated in the drawing.

Both standards within the framework of the ECSD resonate well with each other and fairly divide responsibilities by type:

Options for depicting welds in drawings.

Manual arc connections according to GOST 5264-80:

• C1 – C40 butt
• T1 – T9 T-bar
• H1 – H2 overlap
• U1 – U10 corner

Gas shielded welding connections according to GOST 14771-76:

• C1 – C27 butt
• T1 – T10 tee
• H1 – H4 overlap
• U1 – U10 corner

In our abbreviation, in the second square, GOST 14771-76 is indicated, and in the third T3 - the double-sided T-bevel method without beveled edges, which is precisely indicated in this standard.

Square No. 4, welding methods

How are the different types of seams designated?

The standards also contain designations for welding methods; here are examples of the most common ones:

• A – automatic submerged without cushions and linings;
• Af – automatic submerged arc on a pad;
• ИH – in an inert gas with a tungsten electrode without additives;
• IHP – method in inert gas with a tungsten electrode, but with an additive;
• IP – method in inert gas with a consumable electrode;
• UP is the same thing, but in carbon dioxide.

In square No. 4 we have the welding designation UP - this is a method in carbon dioxide with a consumable electrode.

Square No. 5, seam dimensions

These are the required seam dimensions. It is most convenient to indicate the length of the leg, since we are talking about a T-type version with a perpendicular connection at a right angle. The leg is determined depending on the yield strength.

It should be noted that if the drawing shows a connection of standard sizes, the length of the leg is not indicated. In our drawing designation, the leg is equal to 6 mm.

Classification of welds.

Additional connections are:

• SS one-sided, for which the arc or electrode moves on one side.
• BS double-sided, the melting source moves on both sides.

The third participant in our drawing and welding party comes into play - GOST 2.312-72, which is dedicated to images and symbols.

According to this standard, seams are divided into:

• Visible, which are depicted as a solid line.
• Invisible, indicated in the drawings by a dotted line.

Now let's go back to our original seam. We are able to translate this welding symbol into simple text that is understandable to the human ear:

Double-sided T-seam by manual arc welding in protective carbon dioxide with edges without bevels, intermittent with a staggered arrangement, weld leg 6 mm, length of the welded area 50 mm, pitch 100 mm, remove the convexities of the seam after welding.

Source: https://tutsvarka.ru/vidy/oboznachenie-svarki-na-chertezhah-po-gost

Rules for designating welding joints in drawings according to GOST

Today there are more than 60 types of welding. Welding joints made using different technologies and GOST standards differ in the chemical composition of the weld material and their mechanical characteristics.

The choice of welding type is carried out at the design stage and is based on the results of structural strength calculations. In order for the designer to be able to succinctly and completely display technological solutions in terms of the welded joints used in the drawings in the project, and for the contractor to easily read the design documentation, the welding designation system in the drawings GOST 2.312 - 72 was adopted.

It establishes mandatory graphic symbols for use when preparing design documentation, used to indicate welds in drawings.

document

GOST defines a symbolic structure used to display standard types of welding in drawings. The symbol consists of several blocks of information separated by a hyphen.

At the beginning of the structure there is a main block that includes a display that defines the nature of the weld. So, in accordance with the accepted classification, it can be a closed, open, intermittent or point seam.

The graphic symbols used in GOST look like a circle with a diameter of 3–5 mm, a rectangle with a side missing on the left, a figure in the form of the Latin letter Z, or a straight line segment inclined to the right and forming an angle of 60° with the horizontal.

All symbols used as a means of displaying various types of welding in drawings are drawn with thin solid lines and have the same height as the designation of the type of weld.

After the main block of information there are six additional ones, some of which may be missing. Additional blocks include the following information:

1. GOST, which defines the standards for performing this type of welding of parts;
2. a graphic symbol that indicates a connection in the drawing according to GOST, consisting of letters and numbers;
3. GOST for the type of welding used. For example, if welding is manual, GOST 5264 - 80 is indicated;
4. the size of the leg, which is indicated by the number after the image of a right triangle (the accepted designation of the leg);
5. information clarifying the characteristics of the weld.

If the seam is intermittent, the penetration length and pitch are indicated, if the welding is spot welding, the diameter of the point (calculated). For the electric riveting or contact process, the diameters of the points, as well as the pitch, are indicated.

For the seam type of resistance welding - the calculated welding width. In the case of using intermittent seam resistance welding, the width and length of the seams, as well as the pitch between them, are indicated.

In the last block of information, space is allocated for placing additional information, at the discretion of the designer, of a clarifying or complementary nature.

Accepted simplifications

Information about welded joints may not be placed on the drawing directly at the designation of the contact performed by welding, but may be contained in a separate table.

This table summarizes data on all or part of the joints of the parts of a given design. It contains symbolic designations, as well as their interpretation.

In the table of welded joints, the format of the data indicated may not coincide with that used in the given designation structures. References to GOSTs according to which these seams are made are required.

If a diagram or design drawing contains a number of connections made by welding according to one GOST, having the same properties, a designation in accordance with the structure can be placed only on one of them, a line with a flange is drawn to the rest and a serial number common to all these seams is indicated .

A combined designation on the drawings is allowed if we are talking about connections of the same type, having the same cross-sectional dimensions. In addition, all these connections must be subject to uniform technological requirements.

When making a number of connections in accordance with one GOST, an entry like: “Seams No. according to GOST” is made on the drawing, in the table of seams or technical requirements.

If the design contains all seams of the same type, it is permissible not to number them in the drawing. Such objects are marked with extension lines that do not contain shelves.

Structures that have a symmetrical shape with the axis of symmetry shown in the drawing can have symbols on only one of the symmetrical parts.

The same requirements for a number of connections are stated once, in summary tables or technical requirements. They represent a list available to anyone who decides to repeat the design or understand its structure.

Source: https://svaring.com/welding/teorija/oboznachenie-svarki-na-chertezhah-po-gost

Designation of a weld seam on a drawing according to GOST - welding drawings

There are legally established GOSTs, which spell out all the designations for welding seams. Knowing all the features and recording the designations will allow you to quickly and efficiently complete all the work on welding parts. The drawings have a lot of features, for example, the same designation of different seams, or the numbering of welded elements. Only knowledge of all the “pitfalls” of the project will allow you to quickly understand its essence.

Basic designations

Welded structures use materials of different thicknesses, sizes and shapes; in addition, the parts may have different locations in relation to each other. The designation of a weld seam in the drawing directly depends on the relative position of the welded structural elements. Only 5 types of connections have been installed (according to GOST 5264 and GOST 14771):

— “C” docking;

— “C” end;

— “U” angular;

— “N” overlap;

— “T” Tee.

A butt weld in the drawing is a connection of elements that are located on the same surface or plane. The process of welding parts occurs on adjacent end sides.

End connection “C” is the welding of elements along the end faces of parts whose side surfaces are together. This method is used when welding parts made of thin metal in order to eliminate the possibility of burn-through. The designation of welds in the drawings with the same letters, for example, butt and end, must have an explanation regarding the specific type of weld used.

Designation of welding seams in drawings with a capital letter H when welding using the overlap method. When welding, parts are arranged on parallel lines in such a way that one element partially overlaps the other.

T is the designation on drawings for a T-weld. The end part of one part is connected to the end part of another part at a certain angle (maybe 90 degrees).

The last type “U” - angular, is a seam that is obtained as a result of the arrangement of the welded elements at a right, acute or obtuse angle relative to each other.
A weld seam in a drawing, regardless of what type of welding was used, can be designated as visible or invisible.

The visible type of seam is indicated by a solid line, the invisible seam is indicated by a dotted line. A single weld point, which is visible, is indicated in the drawings with a “+” sign; an invisible one does not have any designations.

Features of indicating seams in the drawing

If the drawing has seams that were made according to the same standards, then the welding drawings and designations will be the same, but this should be indicated in the technical requirements of this drawing.

In the drawings, identical seams can be numbered, but only if all seams are identical to each other and have a one-sided image, for example, only on the front or back side. If the seam does not have any designation, it should be marked on the drawing as a line - a leader that does not have flanges.

The designation of a weld seam in the drawing of a symmetrical product should be represented by leader lines, and the seams themselves should be depicted only on one of the symmetrical parts of the product. But this is only possible if there is an axis of symmetry.

Drawings: GOST requirements

Welding, a designation on a GOST drawing, where there are identical components of one part that were welded with seams of the same type, can be designated as leader lines. The seams can be indicated only for one part of the part; the best option is an image next to which there is a line - a leader.

Some welds may not be marked with leader lines in the drawing, but are indicated as welding explanations in the technical requirements and notes to the drawing. The designation of the weld seam in the drawing is a mandatory condition; it is in the technical requirements; it must contain information about the type of weld seam, the dimensions of the parts and their design features, and the location of the weld seams in the cross section.

All seams or a group of seams in the drawing are given the same set of requirements, which should be located either in the table or in the technical description.

Welding (designation on the GOST drawing) must fully comply with all established requirements. A well-drawn drawing is the key to fast and efficient work by welders. A drawing that is not made in accordance with GOST requirements will not be accepted by the authorities.

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