The scale of a drawing is the ratio of its linear dimensions to the natural size of the depicted object. This makes it possible to judge the parameters of the object under consideration. It is not always possible to use natural dimensions when drawing up a drawing. There are several reasons for this:

1. Some details are too big sizes to fully display them on paper.
2. Other mechanisms or objects, on the contrary, are not large enough to be displayed. An example is a watch, the internal mechanism of which cannot physically be displayed on paper in real size.

In such cases, images are drawn reduced or enlarged.

Standard scales

The scale of reduction includes:

• 1:2,
• 1:2,5,
• 1:4,
• 1:10,
• 1:15,
• 1:20,
• 1:25,
• 1:50.
• 1:75.

The first number indicates that the image scale is half the size of the object. In the case when the part or mechanism is small, other designations are used: 2:1, 2.5:1, 5:1, 10:1. Also, magnification is made by 20, 40, 50 and 100 times.

How to determine scale

To correctly determine the scale of drawings according to GOST, you need to know the parameters of the part or mechanism. If the object is large, then you can reduce it by dividing by the numbers presented. An example would be doubling the size. If a part, reduced by half, will fit on a sheet of drawing paper, then the scale is 1:2.

Any object that needs to be depicted can be measured using standard methods (using a ruler, for example), and then transferred to paper. The same thing happens when creating something based on a drawing. According to the specified scale, the exact dimensions are determined.

Mainly drawings are used:

• during construction,
• when creating complex mechanisms,
• during the development of parts.

Changing the size allows you to work on designing an item on small surface paper, which simplifies the process. If the scale a certain area drawing differs (which happens during construction), then a designation with the required number is placed next to it.

When creating drawings, many students make mistakes due to lack of experience and knowledge. To avoid this, just order the services of our company. Specialists will quickly complete the work, which will allow you to get good mark and see an example of a high-quality drawing. In addition, you can order coursework from us, thesis or an abstract, which will be completed strictly within the agreed time frame.

Why is it necessary to follow GOST

The document regulating the application of inscriptions, tables, as well as technical requirements, highlights the rules by which each drawing is drawn up in accordance with certain standards. This helps create graphical information that is understandable to any engineer or builder who uses it in their professional activities.

Careful reading of the documents will allow you to correctly present the information and scale of the drawings. GOST 2.302-68*contains the following rules:

• Additional text is only created if presenting graphical information is not practical.
• Everything that is on the drawing must be written in a concise form.
• Each inscription should be displayed parallel to the main one.
• If abbreviations of words are not generally accepted, their presence is unacceptable.
• Only short inscriptions are used around the images, which cannot interfere with the reading of the drawing.
• If the leader line is directed to the surface of the part, then it should end with an arrow, and if it intersects the contour and does not point to a specific place, its end is drawn with a dot.
• If there is a large amount of information that needs to be indicated near the drawing, it is framed.
• If there are tables, they are drawn up in empty space next to the image.
• When using letters to designate drawing elements, they are written in alphabetical order without spaces.

Compliance with all these rules will allow you to create a drawing that meets all requirements and therefore will be convenient for use.

But it is not always possible to use a 1:1 scale due to the fact that the size and complexity of the products shown in the drawing are different; some products (for example, machine tools) are so large that their images on a scale of 1: 1 would require huge sheets of paper, drawing boards of the appropriate size, measuring rods, etc.; it is not possible to do all this. Some products (for example, watch movements) are so small that it is almost impossible to depict them on a scale of 1: 1 and, in addition, from such an image it is sometimes impossible to understand the shape and size of not only individual elements, but even entire parts.
In such cases, product images are either reduced or enlarged.
GOST 3451-59 establishes the following scales of images in drawings, as well as their designation:

If there is a need for a greater reduction or increase in comparison with the scales indicated above, the following should be used:
Scale of reduction
1:10n (for example, 1:100; 1:1000, etc.);
1: (2-10 n) (for example, 1: 200; 1: 2000, etc.);
1: (5-10 n) (for example, 1: 500; 1: 5000, etc.);
Scale of increase
(10-n) : 1, for example: 20: 1; 30:1, etc., where n is an integer.
For a visual comparison of the values flat figures, depicted at various scales, Drawing 61 shows images of a square (the side of which is 20 mm), made in different scales: 5:1; 2:1; 1:1; 1:2; 1:5. When choosing a scale, you need to take into account the size and complexity of the object being depicted and the size of the selected drawing format. When making a drawing using a reduction (or enlargement) scale, it is recommended to use an “angular scale” instead of calculations (see Drawing 115).

When depicting a part on an enlarged scale may be drawn on the same sheet (on the left top corner) its simplified image in life size. The scale 1:1 is indicated above the image. Dimensions are not indicated on such an image (see Drawing 640). If the scale fits into the column with the name provided for it in the corner stamp, then it is designated 1:1; 1:2; 2:1, etc. (Drawings 497 and 523), and in other cases M 1:1; M 1:2; M 2:1, etc. (Drawing 640).
In cases where the image is made on a scale different from that inscribed in the corner stamp, the scale must be indicated under the inscription relating to this image (View A / M 2:1); (P / M 5:1) see Drawing 641. On tabular, “silent” and similar drawings, scales are not indicated; in this case, a line is drawn in the column of the corner stamp intended to indicate the scale.
The established scales do not apply to drawings obtained by printing or photography.
We note that in the drawings, regardless of the scale on which they are made, only natural (actual) dimensions are indicated and the dimensions of the depicted part are judged from them. Applying reduced or enlarged dimensional numbers obtained from applying reduction or enlargement scales to the drawing is a mistake.

Layout of the drawing.

The layout of the drawing is the placement of images, dimensions and inscriptions on the drawing field (that is, inside the frame).

The layout of the drawing begins by choosing the drawing format in accordance with the overall (i.e., the largest in length and width) dimensions of the future image. For example, if the overall dimensions of the image are 218 X 170, then you need to choose a format that has a slightly larger drawing field, for example, format 11; its drawing margin is equal to the format size minus the margins of the frame and stamp, i.e.
x = 247 x 180.
If the overall dimensions of the image are 360 ​​X 200, then you need to select format 12; its drawing field dimensions are slightly larger than the image dimensions.
It is recommended to place format 11 so that its short side is at the bottom (210 mm), and format 12 and subsequent ones so that its bottom is at the bottom. long side(420 mm).
In the case when the image of an object is very simple, and its overall dimensions are large, it is possible to apply a reduction scale without compromising understanding, therefore, the drawing should be executed in a format whose drawing field is slightly larger than the overall dimensions of the reduced image. When depicting an object that is complex in shape, but very small in size, you should apply an enlargement scale, and therefore draw it on a format whose drawing field is slightly larger than the overall dimensions of the enlarged image of the object.

With the correct layout of the drawing, the overall cell of the image should be at the same distance from the frame lines on the right and left; above the frame and below the stamp are also at the same distance.
With this arrangement, for images that have vertical and horizontal axes of symmetry, the center O of the drawing field is found (Drawing 62, a), and the image of the object is drawn in such a way that the intersection point of the symmetry axes coincides with the center O of the field (Drawing 62, b).
If there are no prerequisites for depicting an object in a particular position (for example, instructions about the working position of the object, its main view, etc.), then it is recommended to position the image of the object so that its outline is located everywhere at more or less the same distance from frame lines and drawing stamp (i.e., so that the drawing field is more fully used). (Drawing 62, b) shows the correct, and (Drawing 62, c) incorrect (the outline of the image almost touches the side lines of the frame, and above and below there are large, unfilled spaces in the drawing field) layout of the image of the flange outline.
If the image of an object has only one axis of symmetry, for example vertical (Drawing 63, a), then it is combined with a vertical line passing through the center O of the drawing field, then at a distance a2, set upward from the stamp, draw the bottom line of the image of the object and, orienting on these lines, the entire image is constructed; size a 2 = (a - a 1)/2, where a is the vertical size of the drawing field, and size a 1 is the vertical overall size images of the object (Drawing 63, b).

If the image of an object is asymmetrical (does not have axes of symmetry, drawing 64, a), then according to the overall dimensions of the object, draw a dimensional cell inside the drawing field, located to the left of the frame at a distance b 2 = (b - b 1)/2 a from below the stamp on distance a 2 = (a - a 1)/2 (drawing 64, b) and an image of an object is drawn inside it.
In the case when it is necessary to draw not one, but two separate images inside the drawing field (Drawing 65, a), first draw two dimensional cells in such a way that
b 2 = (b - b 1)/2;
d 3 = (b - b 1)/2;
a 2 = (a-(a 1 + k + a 1))/2,
where b is the horizontal overall dimension of the drawing field; b 1 is the horizontal overall dimension of the first item, and b 1 is the horizontal overall dimension of the second item; a - vertical overall dimension of the drawing field; a 1 is the vertical overall dimension of the first item, a 1 is the vertical overall dimension of the second item; k is the size of the distance between the dimensional cells (in the vertical direction) (Drawing 65, b); then images of objects are drawn inside the dimensional cells (Drawing 65, c). If the size k between the overall cells does not depend on the number of sizes that need to be placed between the overall cells, then it is taken equal to a 2 ; Then
a 2 =(a - (a 1 + a 1)) / 3
In the case when it is necessary to apply images of an object on any side a large number of dimension lines, when arranging the drawing, you should move the dimensional cell to one side or another in such a way that required amount dimension lines are freely placed between the outline of the image of the object and the lines of the frame (or stamp). An example of such a layout is shown in (Drawing 66, a - c).
If you need to make a drawing based on an existing sketch of an object with dimensional lines applied, then to assemble it you should add the overall size of the object with the dimensions of the distances between the dimensional lines in the vertical and then horizontal directions and, according to the resulting dimensions, draw a general dimensional cell (drawing 67 , A). The further layout of the image is similar to the data previously indicated (B drawing 67, b and c).

This article covers the main questions about how to How to make a drawing, scale of drawings, design of drawings, etc.

The problem of designing a drawing on their own often arises among students initial courses those engaged in technological specialties or receiving education in the field of artistic design or technical design. The rules that must be followed when creating drawing works are recorded in Gosstandart. Anyone who receives education in these areas should know and adhere to them. However, the Gosstandart rules were issued for industrial use, so small deviations from the established standards are sometimes allowed in the drawings.

Paper sheet formats and frames for them

Any drawing is drawn up on a sheet of paper of a standardized size, limited by a frame. Such a frame is applied by drawing a line of medium thickness along the markings marked on the sheet.

For drawings of different formats, certain dimensions of the frames outlined in them are established:

• A0 format contains a frame measuring 1189 x 841 mm
• A1 format – 594 x 841 mm
• A2 format – 594 x 420 mm
• A3 format – 297 x 420 mm
• A4 format – 297 x 210 mm

Each smaller drawing is obtained by halving the values ​​of the previous format.

Title block of the drawing

The inscription on the drawing is located in the corner located on the right. It states:

• Title of drawing work
• The material from which this part is made
• The company that manufactures the part

When using A4 format, the main inscription is placed on the smallest side. If the format used is larger than A4, then the inscription can be placed on either side.

Initial data for the drawing and working with it

To do simple drawing, you can either depict the detail that the drawing will depict in the future, on paper, in the form of a drawing in three projections, or have it before your eyes in the original.

When depicting a part in the form of a three-dimensional drawing, it is useful to:

• First, practice on simple objects - a notebook, a book, a plate - with your eyes closed, try to imagine their volume and outline
• Try to display on a piece of paper what you presented and compare the result with the original
• Make corrections to parts of the resulting drawing that do not correspond to its original - it is possible that the proportions or its dimensions are not observed
• Try to “decompose” a drawing depicted in space into its component projections along the coordinate axes imagined
• Draw on the drawing all the dimensions required for someone else to make the item.

If the successive steps of the above algorithm were performed correctly, then the copy of the original depicted on paper will correspond to it. If their similarity was not obtained, adjustments will need to be made to the dimensional chains.

A dimensional chain is the total size of a certain part of an image of an object applied to paper, which cannot be distorted up or down. Of course, depending on what goal you are pursuing when depicting an object in a drawing, the accuracy of the dimensions may vary. For example, for domestic purposes, it sometimes deviates within one to one and a half millimeters, and this is often acceptable. In technical drawing, dimensional chains are established taking into account various factors.

What is needed to “measure” a drawing?

The correct creation of a drawing is not only about observing the external similarity of what is applied to whatman paper or recreated in computer program images with a real object. For technical purposes, it is necessary that all dimensions of the image match the original. In this regard, the concept of accuracy tolerance was introduced.

Dimensional tolerances indicated in technical drawings are indicated taking into account the articulation of two adjacent parts with each other. A whole system of tolerances has been developed, taking into account how parts interact with each other (moving or stationary interaction), as well as the nature of probable movements during their assembly or disassembly (often, rarely, always, never) and so on.

How to learn to read drawings?

Drawings are 2-dimensional architectural schematic sketches that show the size of a building's design. For materials that will be used in construction. Learning to read blueprints is important for builders and anyone who hires architects to draw them.

Spatial imagination training

Standard drawings usually have three projections of an object in which the coordinate points X, Y, Z are located on the axis. However, with their composition, the scaling remains and the same is set for all.

It is human nature to observe each object or detail in geometric isometry from a certain angle of view. This often happens in the branches of mechanical engineering drawing, and in the design development of objects of artistic and technical design. Therefore, it is worth presenting the drawing object as flat in a certain projection.

And an additional detail is the projection connection of different images of the drawing object. If all the elements of both configurations are built incorrectly with scale distortions, which will lead to a discrepancy between the copy of the drawing and the originals. Therefore, it is worth following a number of rules in the process of drawing up a projection:

Measurements are carried out using a ruler - for simple ones, with a caliper or micrometer - for complex parts, for all dimensional elements. Install them mutual arrangement for each of the projections of the part. Compare the results obtained with a real image of the part. With bug fixes. Final distance measurements are taken on the original object or its mock-up drawing. If all the data is correct and matches, then the diagrams and drawings were read correctly.

How to apply dimensions correctly?

It doesn’t matter what scale the drawings are made, all attention is paid to the base of the part and its dimensions. When writing a certain number, the unit of measurement, which is standard, is not shown. To indicate the parameters of the part, a dimensional path is drawn with a number located on it. It is drawn parallel to the part segment and is limited by arrows. Minimum distance between the dimension line and the contour of the part is 10 mm.

How can I get help acquiring independent technical graphics skills? To master the skills of reading drawing tables, it is necessary to conduct a training course and practical work. Carry out repairs simple design household appliances, for the production of new and old element parts. In this case, it is also necessary to make primitive drawings.

Learn how to read drawings correctly, and then learn how to represent a flat picture on a drawing in 3D form. The skills of reading drawings help to competently produce all kinds of objects, assemble them from components, the final product, obtain the entire apparatus, models and much more.

Types of formats

The format of the sheet with the drawing is determined by the length of the line drawn on the edge of the sheet. The internal ones are made with distances of 2 cm from the left side and 5 mm from the others. It is worth adhering to the exact calculations of the drawing so that when reading them there is no disagreement about what the part looks like.

Drawing frame formats are divided into main and additional directions. The first type included all the resulting schemes by halving the lines from point A0. The dimensions for drawing A1 are carried out so that when the largest axis is divided into two, a rectangle similar to the original sample is obtained. The designation of standard formats consists of a letter and a number from one to five.

Automatic drawing creation

The first place was taken by those drawings made using computer-aided design programs. For different designs and details. This applies to two systems - Auto-cad and Compass. They involve reading drawings of a different type. And the image of the entire node is set. And then the parts included in the assembly unit are designed. Thanks to their work with entire libraries of source data. After all, they include profile normalized and standardized elements. Using it in work, the developer is able to insert a fragment into a workpiece by controlling individual parameters, adapt the drawing to the new initial data.

Drawing scales

Necessary requirements and features. Let's start with the fact that scale is the ratio of the linear dimensions of the image depicted on a drawing or map to its actual size on the ground or object. Its use greatly facilitates the preparation of maps and drawings, because it is not always convenient and possible to depict an object in its natural size. There are parts with large dimensions that do not allow them to be drawn on paper, and sometimes the part is very small and in order to display it on paper with all the nuances, you have to significantly increase its size. In the presented cases, zoom out and zoom in are used.

Standard scales

Several common reduction scales:

• 1:2,5

For example, the scaling option is 1:4. Number, coming first- one, denotes the actual dimensional characteristics of the object, while the second number, in this case, four, denotes how many times these actual dimensions have been reduced. When depicting a very small object, an increase in scale is used, and this is indicated as follows: 2: 1; 2.5:1; 50:1. With this option, in order to find out the actual dimensions of the object, it is necessary to divide the dimensions indicated in the drawing by the first number reflected in the scale.

How to determine the scale?

In order to depict an object or detail on a sheet of paper, first you need to find out its true dimensions. This can be done by taking measurements of the object depicted in the drawing using a ruler, and only then figuring out how much its actual dimensions should be reduced or increased when drawing its image on a sheet of paper. Drawings are mostly used in construction and in the development of parts and structures. The use of scaling allows designers and constructors to depict both a huge building and a smaller one on a sheet of paper. exact copy airplane.

How to choose the right and, most importantly, the correct scale when working with drawings? Most inexperienced people, when faced with such a question, tend to make quite a lot of mistakes. However, this can be avoided through experience gained over time, or you can seek help from a teacher.

Why is it necessary to follow the rules?

When drawing up drawings and diagrams, it is necessary to follow certain standards reflected in GOST - a document in which generally accepted rules applying images, inscriptions, tables and technical requirements. With the help of these rules, any specialist who knows how to read drawings can read a correctly completed drawing. This greatly facilitates communication, during construction and production of parts, between designers and workers carrying out the task according to the drawing. In addition to the scale, other information relating to the subject is also included on the drawing. You should know the basic rules for drawing up drawings and diagrams:

• If graphic information is inappropriate, add additional text
• Any inscription on the drawing is written in abbreviation
• Additional inscriptions are applied parallel to the main one
• Words that cannot be abbreviated are not included in the drawing work.
• Any inscription should not clutter the image and, moreover, interfere with reading the diagram
• When we want to make a leader from the surface of a part, the leader line must end with an arrow. And in the case when the outline of a part is indicated, a dot is placed at the end of the line
• A large amount of information on the diagram must be placed in a frame
• Tables in the drawing are placed next to the image of the part itself, in a space free from the drawing
• If we designate the elements of a part with letters, then we use them strictly in alphabetical order without gaps

If you use all the rules presented above, you can create a truly high-quality drawing work that any specialist will be able to read.

Design of drawings

The process of preparing any work required for certification in construction, design and architectural specialties studied at higher educational institutions, involves the production of drawings. Making a drawing is not a simple task. Its creation must be carried out taking into account certain rules. In addition, any drawing work must be prepared on sheets of a certain size.

The nuances of using different formats

The drawing format is limited by the scope of the work, which is drawn on the sheet with a line of minimum thickness.

The completed work allows students to take into account the dimensions of all formats used in the work. By dividing the work into two parts, a drawing is drawn up containing the following characteristics:

• Dimensions of the sides of the drawing – 841 x 1189 millimeters
• The total sheet area is one square meter
• Format of completed work A0

For other drawing formats, the rules also set the parameters for the dimensions of their sides:

• For A4 format – 210 x 297 millimeters
• For A3 format – 297 x 470 millimeters
• For A2 format – 420 x 594 millimeters
• For A1 format – 594 x 841 millimeters

Also, according to GOST, the possibility of using other formats used as a supplement to the drawings produced by students, which are formed as a result of working on changing the basic parameters upward, should be taken into account. At the same time, to create them, a value that is a multiple of the sizes used in the basic formats is used, and the coefficient of the changes made must necessarily be an integer.

Scale is the ratio of the linear dimensions of an image in a drawing to its actual dimensions.

The scale of images and their designation in drawings is established by GOST 2.302-68 (Table 5.3). The scale indicated in the designated column of the title block of the drawing should be indicated as 1:1; 1:2; 1:4; 2:1; 5:1; etc.

Table 5.3 – Drawing scales

When designing master plans for large objects, it is allowed to use a scale of 1:2000; 1:5000; 1:10000; 1:20000; 1:25000; 1:50000.

5.3 Main inscription.

Each sheet is decorated with a frame, the lines of which are spaced from three sides of the format by 5 mm from the left side by 20 mm. The main inscription in accordance with GOST 2.104-68 is placed on the frame line in the lower right corner of the format. On A4 sheets, the main inscription is placed only along the short side. The type and thickness of lines in drawings, diagrams and graphs must comply with GOST 2.303-68. Drawings of the project design documentation are made in pencil. Schemes, graphs, and tables may be made in black ink (paste). All inscriptions on the drawing field, dimensional numbers, and filling out the main inscription are made only in drawing font in accordance with GOST 2.304-81.

Thematic headings are not depicted on the sheets, since the name of the contents of the sheet is indicated in the main inscription. In cases where a sheet with one inscription contains several independent images (poster material), individual images or parts of text are provided with headings.

The main inscription on the first sheets of drawings and diagrams must correspond to Form 1, in text design documents - Form 2 and Form 2a on subsequent sheets. It is allowed to use Form 2a on subsequent sheets of drawings and diagrams.

The corner inscription for drawings and diagrams is located in accordance with Figure 5.1. Filled by rotating the sheet 180 o or 90 o.

Figure 5.1–Location of title block on various drawings

In the columns of the title block, Figures 5.2, 5.3, 5.4, indicate:

– in column 1 – name of the product or its component: name of the graph or diagram, as well as the name of the document, if this document is assigned a code. The name must be short and written in the nominative singular case. If it consists of several words, then a noun is placed in the first place, for example: “Threshing drum”, “Safety clutch”, etc. It is allowed to write in this column the name of the contents of the sheet in the order accepted in the technical literature, for example: “Economic indicators”, “Technological map”, etc.;

– in column 2 – designation of the document (drawing, graphics, diagram, specification, etc.);

– in column 3 – designation of the material (the column is filled in only on drawings of parts). The designation includes the name, brand and standard or specification of the material. If the brand of a material contains its abbreviated name “St”, “SCh”, then the name of this material is not indicated.

Figure 5.2 – Form No. 1

Figure 5.3 – Form No. 2

Figure 5.4 – Form No. 2a

Examples of recording material:

– SCh 25 GOST 1412-85 (gray cast iron, 250 - tensile strength in MPa);

– KCh 30-6 GOST 1215-79 (malleable cast iron, 300 - tensile strength in MPa, 6 - relative elongation in%);

– HF 60 GOST 7293-85 (high-strength cast iron, 600 - tensile strength in MPa);

– St 3 GOST 380-94 (carbon steel of ordinary quality, 3- serial number become);

– Steel 20 GOST 1050-88 (carbon steel, high-quality structural, 20 - carbon content in hundredths of a percent);

– Steel 30 KhNZA GOST 4543-71 (alloy structural steel, 30 - carbon content in hundredths of a percent, chromium no more than 1.5%, nickel 3%, A - high quality);

– Steel U8G GOST 1425-90 (tool carbon steel, 8 - carbon content in tenths of a percent; G - increased manganese content);

– Br04Ts4S17 GOST 613-79 (deformable bronze, O-tin 4%, C-zinc 4%, C-lead 17%);

– BrA9Mts2 GOST 18175-78 (tin-free bronze , processed by pressure, A- aluminum 9%, manganese 2%);

– LTs38Mts2S2 GOST 17711-93 (cast brass, zinc 38%, manganese 2%, lead 2%);

– AL2 GOST 1583-89 (casting aluminum alloy, 2-order alloy number);

– AK4M2TS6 GOST 1583-93 (cast aluminum alloy, silicon 4%, copper 2%, zinc 6%);

– AMts GOST 4784-74 (deformable aluminum alloy, manganese 1.0...1.6%,).

When manufacturing parts from the assortment:

- Square
(from a rod square profile with a square side size of 40 mm according to GOST 2591-88, steel grade 20 according to GOST 1050-88);

– Hexagon
(made of hot-rolled steel with hexagonal profile according to GOST 2579-88 normal accuracy rolling, with the size of an inscribed circle - turnkey size - 22 mm, steel grade 25 according to GOST 1050-88);

- Circle
(hot-rolled round steel of normal rolling accuracy with a diameter of 20 mm in accordance with GOST 2590-88, steel grade St 3 in accordance with GOST 380-94, supplied in accordance with the technical requirements of GOST 535-88);

- Band
(strip steel 10 mm thick, 70 mm wide according to GOST 103-76, steel grade St 3 according to GOST 380-94, supplied according to the technical requirements of GOST 535-88);

– Corner
(angular equal-flange steel 50x3 mm in size according to GOST 8509-86, steel grade St 3 according to GOST 380-94, standard rolling accuracy B, supplied according to the technical requirements of GOST 535-88);

– I-beam
(hot-rolled I-beam number 30 in accordance with GOST 8239-89 of increased accuracy (B), steel grade St 5 in accordance with GOST 380-94, supplied in accordance with the technical requirements of GOST 535-88);

– Pipe 20x2.8 GOST 3262-75 (ordinary non-galvanized pipe of standard manufacturing precision, of unmeasured length, with a nominal bore of 20 mm, a wall thickness of 2.8 mm, without threads and without a coupling);

– Pipe Ts-R-20x2.8 – 6000 GOST 3262-75 (zinc-coated pipe with increased manufacturing precision, measured length 6000 mm, nominal bore 20 mm, with thread);

- Pipe
(steel seamless pipe normal manufacturing precision according to GOST 8732-78, with an outer diameter of 70 mm, wall thickness of 3.5 mm, length multiple of 1250 mm, steel grade 10, manufactured according to group B of GOST 8731-87);

- Pipe
(steel seamless pipe according to GOST 8732-78 with internal diameter 70 mm, wall thickness 16 mm, of unmeasured length, steel grade 20, category 1, manufactured according to group A, GOST 8731-87);

– Column 4 – letter assigned to this document according to GOST 2.103-68 depending on the nature of the work in the form of a project. The column is filled in from the left cell:

–U – educational document;

–DP – documentation of the diploma project;

–DR – documentation of the thesis;

–KP – course project documentation;

–KR – course work documentation;

– Column 5 – product weight (in kg) according to GOST 2.110-95; on drawings of parts and assembly drawings indicate the theoretical or actual mass of the product (in kg) without indicating units of measurement.

It is allowed to indicate the mass in other units of measurement indicating them, for example, 0.25 g, 15 t.

In drawings made on several sheets, the mass is indicated only on the first.

On dimensional and installation drawings, as well as on drawings of parts of prototypes and individual production, it is allowed not to indicate the mass;

– Column 6 – scale (indicated in accordance with GOST 2.302-68).

If the assembly drawing is made on two or more sheets and the images on individual sheets are made on a scale different from that indicated in the title block of the first sheet, column 6 of the title block on these sheets is not filled out;

– Column 7 – serial number of the sheet (on documents consisting of one sheet, the column is not filled in).

Column 8 – the total number of sheets of the document (the column is filled out only on the first sheet).

Column 9 - the name or distinctive index of the enterprise issuing the document (since the department in which the diploma project is being carried out is encrypted in column 2 - designation of the document, in this column it is necessary to enter the name of the institute and the group code). For example: “PGSHA gr. To-51";

– Column 10 – the nature of the work performed by the person signing the document. In the diploma project, the column is filled in starting from the top line with the following abbreviations:

– “Developer”;

– “Consult.”;

- “Hand. etc.";

- “Head. cafe";

- “N.cont.”

– Column 11 – surname of the persons who signed the document;

– Column 12 – signatures of persons whose names are indicated in column 2. Signatures of the persons who developed this document and are responsible for standard control are mandatory;

– Box 13 – date of signing of the document;

Machines and some of their parts, buildings and their parts are large, so it is not possible to draw them in full size. Their images have to be drawn in . Smallest details wristwatch and other mechanisms have to be drawn, on the contrary, on an enlarged scale.

In all cases where possible, details should be drawn in actual size, i.e. on a scale of 1:1.

Reducing or enlarging images any number of times is not permitted. GOST 2.302-68 establishes the following reduction scales: 1:2; 1:2.5; 1:4; 1:5; 1:10; 1:15; 1:20; 1:25; 1:40; 1:50; 1:75; 1:100; 1:200; 1:400; 1:500; 1:800; 1:1000. When drawing up master plans for large objects, it is allowed to use a scale of 1:2000; 1:5000; 1:10,000; 1:20,000; 1:25,000; 1:50,000. Magnification scales are written as a ratio to unity; The standard establishes the following magnification scales: 2:1; 2.5:1; 4:1; 5:1; 10:1; 20:1; 40:1, 50:1; 100:1. If necessary, it is allowed to use magnification scales (100l): 1, where n is an integer. In cases where the full word “scale” is not included in the entry, the letter M is placed before the scale designation, for example they write: M 1:2 (reduction scale), M 2:1 (increase scale). In Fig. 1 washer rectangular shape depicted in three scales: life-size (M 1:1), reduced scale and enlarged scale. Linear dimensions the last image is four times larger than the middle one, and the area occupied by the image is sixteen times larger. This sudden change The size of the image should be taken into account when choosing the scale of the drawing.

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Rice. 1. Comparison of different scales. Linear scales

In addition to numerical scales, linear scales are used in drawing. Linear scales There are two types: simple and transverse (Fig. 1). A simple linear scale, corresponding to a numerical scale of 1: 100, is a line on which, from the zero division, centimeter divisions are laid out to the right, and one of the same divisions, divided into millimeters, to the left. Each centimeter division of the linear scale corresponds to 100 cm (or 1 m). Each millimeter division corresponds, obviously, to one decimeter. Having taken any size from the drawing with a meter, place one needle on the corresponding full division to the right of zero, on -
example for division 3. Then the second needle will show how many decimeters over 3 m the measured size has. In this case it is equal to 3.4 m.

The advantages of a simple linear scale over a regular ruler are as follows:

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1. it is always on the drawing;
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2. gives more accurate readings, since the dimensions in the drawing are plotted, as a rule, according to a given linear scale;
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3. After photographing the drawing, the scale, decreasing proportionally, makes it possible to obtain dimensions without constructing a proportional scale.
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More perfect is linear transverse scale. In the drawing it is given for the same scale of 1:100. Oblique lines, transversals, allow you to get not only decimeters, but also centimeters. As an example, the scale shows a size of 3.48 m. Linear scales are used primarily in construction and topographical drawings.

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Rice. 2. Scale chart

In design and production practice often use proportional (angular) scale. It is a simple graph. Suppose you need to construct such a graph for a scale of 1:5. On a horizontal line from point A (Fig. 2) lay a segment equal to 100 mm; at point B, a right angle is constructed and a segment reduced by 5 times (100: 5 = 20 mm) is laid along its second side; connect the resulting point C to point A. The value of 12.8 mm, corresponding to 66 mm, is taken with a measuring compass directly from the graph, without calculating it or using a ruler. The graph is drawn on graph paper or on checkered paper.

For a scale of 1: 2.5, 40 mm are set aside on the continuation of the leg of the aircraft, for a scale of 1: 2-50 mm. The series of proportional scales shown in the figure is called a scale graph. Using it allows you to save a significant amount of time. Having constructed a scale graph, use it throughout the entire work on the drawing course.