When choosing a scale for drawings, we use the following GOST standards:
GOST 2.302-68 one system design documentation. Scale.
GOST 21.501-2011 System of design documentation for construction. Rules for the execution of working documentation of architectural and structural solutions.
GOST R 21.1101-2013 System of design documentation for construction. Basic requirements for design and working documentation
When developing drawings, the dimensions of graphic images of structures, components, and diagrams, as a rule, do not correspond to real dimensions. Size ratio graphic image there is a certain ratio to the size of the depicted object, which is usually called scale. To be precise:
Scale is the ratio of the linear dimensions of the image of an object in the drawing to its actual dimensions.
In accordance with GOST R21.1101-2013, construction drawings, as a rule, do not have scales
put down.
In cases where the images on the sheet are made in different scales, the corresponding scale is indicated above each of them.
Architectural and construction drawings of residential and public buildings carried out on the following scales:
floor plans, sections, facades – 1:50; 1:100; 1:200
fragments of plans, sections, facades – 1:50; 1:100
knots – 1:5; 1:10; 1:20
master plan – 1:500; 1:1000
In some cases it is necessary to choose other scales. Let's consider common list existing scales.
GOST 2.302 establishes the scale of images for drawings.
Scales can be of the following types:
| Natural | Magnification scale | Reduction scale |
| 1:1 | 1: 2 | 2:1 |
| 1:2,5 | 2,5:1 | |
| 1:4 | 4:1 | |
| 1:5 | 5:1 | |
| 1:10 | 10:1 | |
| 1:15 | 20:1 | |
| 1:20 | 40:1 | |
| 1:25 | 50:1 | |
| 1:40 | 100:1 | |
| 1:50 | ||
| 1:75 | ||
| 1:100 | ||
| 1:200 | ||
| 1:400 | ||
| 1:500 | ||
| 1:800 | ||
| 1:1000 |
When developing drawings, the image scale should be taken as minimal as possible, depending on the complexity of the drawing, but ensuring the clarity of copies made from them.
Rice. 26. Part drawing without dimensions
Obviously, this cannot be done, since there are no dimensions.
Drawing dimensions on drawings is a very important operation that significantly affects the ease of reading the drawing.
Rules for applying dimensions are established by standards ESKD (GOST 2.307-68).
When applying dimensions, the following symbols are used: S (thickness), ø (diameter), R (radius), (square).
Sizes available linear and angular. Linear dimensions indicate the length, width, height, thickness, diameter or radius of the part being measured. Angular dimension denotes the size of the angle.
Linear dimensions in the drawings are indicated in millimeters, but the unit of measurement is not indicated.
Angular dimensions indicated in degrees, minutes and seconds with the designation of the unit of measurement.
The number of dimensions in the drawing should be minimal, but sufficient for the manufacture and control of the product.
To apply dimensions use remote And dimension lines, which are drawn with a continuous thin line.
Leader lines- lines that indicate size.
Dimensional lines– the lines on which the size is placed ends with arrows at both ends. The arrows must touch the extension lines; the shape of the arrow is shown in Fig. 27.
Rice. 27. Arrow shape
The dimension line is always drawn parallel to the contour line of the part of the part whose size it defines and perpendicular to the extension lines. If the size is less than 12 mm, then the arrows are placed outside, and if more than 12 mm, then inside (Fig. 28). The dimension line is 10 mm away from the contour of the part drawing, the distance between parallel dimension lines must be at least 7-10 mm.
Extension lines extend beyond the ends of the arrows of the dimension line by 1-5 mm. The size is placed above the size line, closer to its middle.
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Rice. 28. Examples of sizing
With a vertical dimension line, the dimension number is written to the left of it.
The same size is placed in the drawing only once.
First, the smaller size is taken out, and then the larger one. In the drawing, dimension lines should not intersect.
When specifying the size of an angle, the dimension line is drawn in the form of a circular arc with the center at the vertex of the angle.
Diameter sign is placed in front of the dimension number if the circle is drawn completely. The dimension line is drawn through the center of the circle. If the part has several identical holes, then the size is set once, indicating the number of holes (see Fig. 28).
Radius sign is placed when part of a circle is drawn, the dimension line is drawn from the center of the arc.
You should remember the basic concepts:
1) element sizes – dimensions of cutouts, protrusions, holes, grooves;
2) coordinating sizes – dimensions showing the location of the elements relative to the contour of the part and each other;
3) dimensions - nai big sizes details in length, height, width.
In drawing practice, you have to draw images of very large parts (machine tools, ships, cars) and very small ones (clock mechanisms, precision instruments).
Is it possible to depict them in life size? Of course, it’s impossible, so large objects are depicted reduced, and small ones - enlarged, i.e. apply scale
(Fig. 29).
Rice. 29. Scale designation in the drawing
Scale– the ratio of the linear dimensions of the image of an object to its actual dimensions.
The scale of images and their designation are established by the standard (GOST 2.302-68).
natural size – 1:1(one to one);
reduction scale – 1:2; 1:25;1:4;1:5; 1:10; 1:15;
magnification scale – 2:1; 2.5:1; 4:1; 5:1; 10:1; 15:1.
The scale is indicated by the letter M on the drawing field, for example M 1:2. The letter M is not placed in the main inscription. Whatever the scale of the drawing, the actual dimensions are always indicated.
Sometimes you have to determine the scale at which an object is drawn. In this case, they do this: determine the size of the side (for example, A) using a measuring ruler, it is equal to 50 mm. The actual length of the segment indicated in the drawing is 100 mm. Consequently, the scale is determined as the quotient of dividing 50 by 100 and is equal to 1:2 (Fig. 30).
Rice. 30. Determining the scale of a part in a drawing
Every computer graphics program has a Loupe tool. It allows you to instantly change the scale of an image (drawing, picture), increasing (decreasing) it to the desired size (Fig. 31).
Rice. 31. Using scale in computer programs Loupe tool
Drawing font
In a wide variety of fields of science, technology, and design, people use fonts to write letters, numbers, symbols and other symbols.
Font– a method of encoding text information.
Each type of graphic activity is characterized by certain fonts. In many cases, artistic elements (decorations) are added to the font, giving it greater expressiveness.
The main types of fonts that were most often used throughout historical development written culture of mankind are presented in Fig. 32.
Rice. 32. Types of font
Computer fonts are popular these days. All inscriptions on the drawings are made in drawing font - GOST 2.304-81.
GOST sets the following font numbers: 1.8 (not recommended, but allowed); 2.5;3.5;5;7;10, as well as the height, width of letters and the distance between letters.
For drawings made in A4 format, the following font numbers are recommended: 2.5; 3.5; 5; 7. The standard establishes two types of font - uppercase (capital letters) and lowercase. By design, uppercase and lowercase letters can be divided into three groups (Fig. 33).
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Rice. 33. Drawing font
Capital letters:
Group 1 – G, P, N, T, E, C, Sh, Shch;
Group 2 – I, X, K, F, M, A, L, D;
Group 3 – Ch, U, B, V, R, Ya, O, S, E, Yu, F, S, b, b.
Lower case:
Group 1 – p, y, c, t, w, sch, i;
Group 2 – o, a, b, c, d, y, r, f, s;
Group 3 – f, b, i, g, g, h, j, l, m, n, x, h.
According to their proportions, they can be divided into wide and narrow: wide capitals - Ш, Ш, Ж, Ю, И, Ф; wide lowercase - t, sh, shch, yu, ы, m. The letters of the drawing font are written in a simplified form. The capital font number corresponds to the height of the letters, and the width corresponds to the smaller previous number, for example, font number 7, the height of the letters is 7, the width of the letters is 5. The width of wide letters corresponds to the height. The distance between letters is 2 mm.
Height lowercase letters corresponds to the lower previous number of the font, and the width corresponds to the next previous number, for example, font number 7, the height of the letters is 5, the width is 3.5, the width of wide letters corresponds to the height of the letters. The distance between letters is 1.5 mm.
To correctly execute the letters on initial stage use a grid.
The main inscription is filled in font No. 3.5; the title of the drawing is in font No. 7 or No. 5 (Fig. 34).
Rice. 34. Sample of filling out the title block
Remember, the stitches do not touch the frame line.
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 must 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 square profile bar 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 a hexagonal profile in accordance with GOST 2579-88 of normal rolling accuracy, with the size of an inscribed circle - turnkey size - 22 mm, steel grade 25 in accordance with 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 
(seamless steel pipe in accordance with GOST 8732-78 with an internal diameter of 70 mm, wall thickness 16 mm, 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;
Thanks to technological progress, many programs have been created to facilitate the process of working on drawings. However, even the most complex and multifunctional programs cannot completely replace a person, and therefore there are many tasks that have to be solved independently. So, quite a lot of questions arise when it is necessary to find out the scale of the drawings. GOST quite strictly regulates everything that is on the drawings, including scale parameters, symbols and so on. However theoretical knowledge do not always help to understand in practice.
What are the drawing scales?
GOST tells us that there are several types of scales: life-size, enlarged scale and reduced scale. The nuance is that when creating drawings, scales cannot be chosen at your own discretion; they must exactly correspond to the parameters specified by GOST:
- Life size - 1:1 is the most convenient because it immediately gives a clear idea of the size of the object.
- Reduction scale - 1:2; 1:2.5; 1:4; 1:5; 1:10; 1:15; 1:20; 1:25 and so on, is used if it is necessary to depict a large object in the drawing, for example a large machine or part.
- Magnification scale - 2:1; 2.5:1; 4:1; 5:1; 10:1; 20:1; 40:1; 50:1 and so on, is used in cases where we are talking about a small part, such as a clock mechanism, a bolt or a nut.
- Special reduction scales are calculated using the formula 1:10n; 1:(2x10n); 1:(5x10n), which are used to depict particularly large objects, such as buildings or bridges.
- Specific magnification scales can be calculated using the formula (10xn):1, where n is an integer. Such scales are used for the smallest and even microscopic details.
How to correctly indicate the scale of drawings?
GOST provides for the designation of the scale of elements shown in the drawings. For this purpose, a special area is used in the lower right corner, which, as a rule, is specially marked. If the column does not have a name, then the letter “M” appears before the digital values, for example, M 1:1; M 1:2; M 2:1 and so on. It is important to remember that if you are making a working drawing of a typical part, then the scale is not indicated, but a dash is placed in the column. If you are drawing a part on an enlarged scale, then in order to imagine actual size details, an image of the part in the upper left corner on a scale of 1:1 is allowed, and the dimensions for such an image do not need to be specified.
Dimensions and scales
Certainly, different meanings Sometimes they can be misleading, but in reality everything is very simple. So, if you see that the scale is 1:100, then the part will be 100 times larger than its image. Conversely, if the scale is 100:1, then the part will be 100 times smaller. In order to avoid unnecessary confusion, all dimensions in the drawings must be indicated in actual size only, regardless of scale. Thus, indicating the dimensions obtained as a result of scaling is a gross mistake.
We understand that GOST prescribes the scale of drawings quite strictly and failure to comply with the standards may lead to the fact that you will have to redo the entire drawing. However, sometimes calculating the required scale is quite difficult. If you are not confident in your abilities and doubt that you will be able to carry out the necessary calculations correctly, you can always resort to the help of our company’s specialists. Our specialists have extensive experience in drawing up various drawings according to all existing GOSTs. They can easily draw a detail or object of any size, from the smallest to the largest.
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 wrist watches 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 installed following scales reduction: 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. IN necessary cases 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. The linear dimensions of the last image are four times larger than the middle one, and the area occupied by the image is sixteen times larger. Such a sharp change in image size 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:
- rn
- it is always on the drawing; rn
- gives more accurate readings, since the dimensions in the drawing are plotted, as a rule, according to a given linear scale; rn
- After photographing the drawing, the scale, decreasing proportionally, makes it possible to obtain dimensions without constructing a proportional scale. rn
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 they 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.