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INTERSTATE COUNCIL FOR STANDARDIZATION, METROLOGY AND CERTIFICATION
(MGS)

INTERSTATE COUNCIL FOR STANDARDIZATION, METROLOGY AND CERTIFICATION
(ISC)

INTERSTATE
STANDARD

GOST
2.307-2011

one system design documentation

DIMENSIONING
AND MAXIMUM DEVIATIONS

Moscow

Standartinform

Foreword

The goals, basic principles and basic procedure for carrying out work on interstate standardization are established by GOST 1.0-92 “Interstate standardization system. Basic Provisions” and GOST 1.2-2009 “Interstate Standardization System. Interstate standards, rules and recommendations for interstate standardization. Rules for the development, adoption, application, updating and cancellation "

About the standard

1 DEVELOPED by the Federal State Unitary Enterprise "All-Russian Scientific Research Institute for Standardization and Certification in Mechanical Engineering" (FSUE "VNIINMASH"), Autonomous non-profit organization"Research Center for CALS-technologies "Applied Logistics" (ANO R&D Center for CALS-technologies "Applied Logistics")

2 INTRODUCED by the Federal Agency for Technical Regulation and Metrology

3 ADOPTED by the Interstate Council for Standardization, Metrology and Certification (Minutes of May 12, 2011 No. 39)

Short country name according to MK (ISO 3166) 004-97	Code of the country according to MK (ISO 3166) 004-97	Abbreviated name of the national authority for standardization
Azerbaijan		Azstandard
		Ministry of Economy of the Republic of Armenia
Belarus		State Standard of the Republic of Belarus
Kazakhstan		State Standard of the Republic of Kazakhstan
Kyrgyzstan		Kyrgyzstandart
		Moldova-Standard
Russian Federation		Rosstandart
Tajikistan		Tajikstandart
Uzbekistan		Uzstandard
		Gospotrebstandart of Ukraine

4 By order of the Federal Agency for Technical Regulation and Metrology dated August 3, 2011 No. 211-st, the interstate standard GOST 2.307-2011 was put into effect as a national standard Russian Federation since January 1, 2012

Information on the entry into force (termination) of this standard is published in the index "National Standards".

Information about changes to this standard is published in the index "National standards", and the text of the changes- V information signs "National standards". In case of revision or cancellation of this standard, the relevant information will be published in the information index "National Standards"

INTERSTATE STANDARD

Unified system of design documentation

APPLICATION OF DIMENSIONS AND MAXIMUM DEVIATIONS

Unified system of design documentation.
Drawing of dimensions and limit deviations

Introduction date- 2012-01-01

1 area of use

This standard establishes the rules for applying dimensions and maximum deviations in graphic documents to products of all industries and construction.

2 Normative references

This standard uses normative references to the following interstate standards:

NOTE When using this standard, it is advisable to check the validity of the referenced standards in information system common use- on the official website of the Federal Agency for Technical Regulation and Metrology on the Internet or according to the annually published information index "National Standards", which was published as of January 1 of the current year, and according to the corresponding monthly information indexes published in the current year. If the reference standard is replaced (modified), then when using this standard, you should be guided by the replacing (modified) standard. If the referenced standard is canceled without replacement, the provision in which the reference to it is given applies to the extent that this reference is not affected.

3 Terms and definitions

In this standard, the following terms are used with their respective definitions:

electronic layout: Electronic product model describing it outer shape and dimensions, which allows to fully or partially evaluate its interaction with elements of the production and (or) operational environment, which serves to make decisions in the development of the product and the processes of its manufacture and use.

4.2 The total number of dimensions should be minimal, but sufficient for the manufacture and control of the product.

4.3 Reference dimensions are marked with a “*”, and in the technical requirements they write: “* Dimensions for reference”. If all dimensions are reference, they are not marked with a "*" sign, but in technical requirements write down: "Dimensions for reference."

On construction drawings, reference dimensions are noted and specified only in cases provided for in the relevant documents approved in the prescribed manner.

4.4 Reference dimensions include the following dimensions:

a) one of the sizes of a closed dimensional chain. Limit deviations of such dimensions are not indicated in the drawing (see Figure 1);

Picture 1

b) dimensions transferred from graphic documents of blank products (see Figure 2);

Figure 2

c) dimensions that determine the position of the elements of the part to be processed on another part (see Figure 3);

Figure 3

d) dimensions on the assembly drawing, which determine the limit positions of individual structural elements, for example, the piston stroke, the stroke of the engine valve stem internal combustion etc.;

e) dimensions on the assembly drawing, transferred from the drawings of parts and used as installation and connecting ones;

e) overall dimensions on the assembly drawing, transferred from the drawings of parts or being the sum of the dimensions of several parts;

g) the dimensions of parts (elements) from sectional, shaped, sheet and other rolled products, if they are fully determined by the designation of the material given in column 3 of the main inscription.

Note - The reference dimensions indicated in listings b) - g), it is allowed to apply both with and without limit deviations.

4.5 In graphic documents for products, the dimensions, the control of which is technically difficult, put the sign "*", and in the technical requirements the inscription "* Dimensions provided. instr.".

Note - The indicated inscription means that the fulfillment of the size established by the drawing with the maximum deviation must be guaranteed by the size of the tool or the corresponding technological process.

At the same time, the dimensions of the tool or the technological process are checked periodically in the process of manufacturing products.

The frequency of control of a tool or a technological process is established by the manufacturer together with the representative office of the customer.

4.6 It is not allowed to repeat the dimensions of the same element in different images, in technical requirements, in the main inscription and specification. The exception is the reference dimensions given in 4.4, listings b), g).

If in the technical requirements it is necessary to refer to the size printed on the image, then this size or the corresponding element is indicated by a letter, and in the technical requirements an entry similar to that shown in Figure 4 is placed.

Figure 4

Dimensions may be repeated on construction drawings.

4.7 Linear dimensions and their maximum deviations in graphic documents and specifications are indicated in millimeters without indicating the unit of measurement.

For dimensions and maximum deviations given in the technical requirements and explanatory inscriptions on the drawing field, the units of measurement must be indicated.

4.8 If in a graphic document the dimensions must be indicated not in millimeters, but in other units of measurement (centimeters, meters, etc.), then the corresponding dimensional numbers are recorded with the designation of the unit of measurement (cm, m) or indicated in the technical requirements.

On construction drawings, units of measurement in these cases may not be indicated if they are specified in the relevant documents approved in the prescribed manner.

4.9 Angular dimensions and limit deviations of angular dimensions are indicated in degrees, minutes and seconds with the designation of the unit of measurement, for example 4 °; 4°30"; 12°45"30"; 0°30"40"; 0°18"; 0°5"25"; 0°0"30"; 30° ± 1°; 30° ± 10".

4.10 For dimensional numbers, simple fractions are not allowed, except for sizes in inches.

4.11 The dimensions that determine the location of the mating surfaces are, as a rule, affixed from the design bases, taking into account the possibilities for the implementation and control of these dimensions.

4.12 When the elements of the object (holes, grooves, teeth, etc.) are located on the same axis or on the same circle, the dimensions that determine their relative position are applied in the following ways:

From the main base (surfaces, axes) - see pictures 5 A and 5 b;

By setting the dimensions of several groups of elements from several main bases - see Figure 5 V;

Dimensioning between adjacent elements (chain) - see figure 6.

Figure 5

Figure 6

4.13 Dimensions in a graphic document are not allowed to be applied in the form of a closed chain, except when one of the dimensions is indicated as a reference (see Figure 1).

On construction drawings, dimensions are applied in the form of a closed chain, except as provided for in the relevant documents approved in the prescribed manner.

Dimensions that determine the position of symmetrically located surfaces of symmetrical products are applied as shown in Figures 7 and 8.

Figure 7

Figure 8

4.14 For all dimensions printed on working graphic documents, limit deviations are indicated.

It is allowed not to indicate limit deviations:

a) for dimensions that define zones of different roughness of the same surface, heat treatment zones, coating, finishing, knurling, notches, as well as diameters of knurled and notched surfaces. In these cases, the sign """ is applied directly to such dimensions;

b) for the dimensions of the parts of single-piece production products, established with an allowance for fit.

On such drawings, in the immediate vicinity of the indicated dimensions, the sign "*" is applied, and in the technical requirements they indicate:

"* Sizes with an allowance for fitting to children .....",

"* Dimensions with an allowance for fit according to hell .....",

"*Dimensions with an allowance for fit on the mating part."

On construction drawings, the maximum deviations of dimensions are indicated only in cases provided for in the relevant documents approved in the prescribed manner.

4.15 When making working drawings of parts manufactured by casting, stamping, forging or rolling with subsequent machining of a part of the surface of the part, indicate no more than one size in each coordinate direction connecting the machined surfaces with surfaces not subjected to machining (see Figures 9 and 10).


Figure 9	Figure 10

4.16 If the element is depicted with a deviation from the scale of the image, then the dimension number should be underlined (see Figure 11).

Figure 11

5 Dimensioning

5.1 Dimensions in graphic documents are indicated by dimensional numbers and dimension lines.

5.2 When applying the size of a straight segment, the dimension line is drawn parallel to this segment, and the extension lines are perpendicular to the dimension lines (see Figure 12).

Figure 12

5.3 When applying the size of the corner, the dimension line is drawn in the form of an arc with a center at its apex, and extension lines - radially (see Figure 13).

Figure 13

5.4 When applying the size of an arc of a circle, the dimension line is drawn concentric to the arc, and the extension lines are parallel to the bisector of the angle and the sign “” is applied above the dimension number (see Figure 14).

Figure 14

It is allowed to place the extension lines of the arc dimension radially and, if there are other concentric arcs, it is necessary to indicate to which arc the dimension belongs (see Figure 15).

Figure 15

5.5 When applying the dimensions of parts similar to those shown in Figure 16, dimension lines should be drawn in the radius direction, and extension lines - along arcs of circles (see Figure 16).

Figure 16

5.6 The dimension line at both ends is limited by arrows resting on the corresponding lines, except for the cases given in 5.17, 5.18, 5.21 and 5.22, and when drawing a radius line bounded by an arrow from the side of the arc or fillet being determined.

On construction drawings, instead of arrows, it is allowed to use serifs at the intersection of dimension and extension lines, while the dimension lines should protrude beyond the extreme extension lines from 1 to 3 mm.

5.7 In the cases shown in Figure 17, the dimension and extension lines are drawn so that they, together with the measured segment, form a parallelogram.

Figure 17

5.8 It is allowed to draw dimension lines directly to the lines of the visible contour, axial, center and other lines (see figures 18 and 19).


Figure 18	Figure 19

5.9 Dimension lines are preferably drawn outside the outline of the image.

5.10 Extension lines should extend beyond the ends of the arrows of the dimension line by 1-5 mm.

5.11 The minimum distance between parallel dimension lines should be 7 mm, and between the dimension line and the contour line - 10 mm and are selected depending on the size of the image and the saturation of the drawing.

5.12 It is necessary to avoid the intersection of dimension and extension lines (see Figure 18).

5.13 It is not allowed to use contour lines, axial, center and extension lines as dimension lines.

5.14 Extension lines are drawn from the lines of the visible contour, except for the cases specified in 5.15 and 5.16, and in cases where when drawing dimensions on an invisible contour, there is no need to draw an additional image.

5.15 The dimensions of the curved profile contour are applied as shown in Figures 18 and 19.

5.16 If it is necessary to show the coordinates of the vertex of the rounded corner or the center of the rounding arc, then extension lines are drawn from the point of intersection of the sides of the rounded corner or the center of the rounding arc (see Figure 20).

Figure 20

5.17 If a view or section of a symmetrical object or individual symmetrically located elements is depicted only up to the axis of symmetry or with a break, then the dimension lines related to these elements are drawn with a break, and the break of the dimension line is made further than the axis or break line of the object (see Figure 21 ).

Figure 21

On construction drawings, in such cases, all dimensions may be indicated only up to the axis of symmetry, and the dimension lines at the intersection with the axis of symmetry should be limited by a cross of serifs.

5.18 Dimension lines may be drawn with a break in the following cases:

a) when specifying the size of the diameter of a circle, regardless of whether the circle is shown in full or in part; at the same time, a break in the dimension line is made further than the center of the circle (see Figure 22);

Figure 22

b) when applying dimensions from a base not shown in the image (see Figure 23).

Figure 23

5.19 When depicting a product with a break, the dimension line is not interrupted (see Figure 24).

Figure 24

5.20 The dimensions of the elements of the arrows of the dimension lines are selected depending on the thickness of the lines of the visible contour and are drawn approximately the same throughout the drawing. The shape of the arrow and the approximate ratio of its elements are shown in Figure 25 A and 25 b.

Figure 25

5.21 If the length of the dimension line is insufficient to place arrows on it, then the dimension line is continued beyond the extension lines (or, respectively, beyond the contour, axial, center, etc.) and the arrows are applied as shown in Figure 26.

Figure 26

5.22 If there is not enough space for arrows on dimension lines located in a chain, it is allowed to replace the arrows with serifs applied at an angle of 45 ° to the dimension lines (see Figure 27), or clearly marked dots (see Figure 28).


Figure 27	Figure 28

5.23 If there is not enough space for an arrow due to a closely located contour or extension line, the latter may be interrupted (see Figures 26 and 29).

Figure 29

5.24 Dimensional numbers are applied above the dimension line as close as possible to its middle (see Figure 30).

Figure 30

5.25 When applying the size of the diameter inside the circle, the dimension numbers are shifted relative to the middle of the dimension lines.

5.26 When applying several parallel or concentric dimension lines at a small distance from each other, it is recommended that the dimension numbers above them be staggered (see Figure 31).

Figure 31

5.27 Dimensional numbers of linear dimensions with different slopes of dimension lines are arranged as shown in Figure 32.

Figure 32

If it is necessary to apply a dimension in the shaded area, the corresponding dimension number is applied on the shelf of the leader line (see Figure 33).

Figure 33

5.28 Angular dimensions are applied as shown in Figure 34. In the area located above the horizontal center line, dimension numbers are placed above the dimension lines from the side of their convexity; in the area below the horizontal center line, from the side of the concavity of the dimension lines. It is not recommended to apply dimensional numbers in the shaded area. In this case, the dimension numbers indicate the horizontally applied shelves.

Figure 34

For small corners with a lack of space, the dimension numbers are placed on the shelves of leader lines in any zone (see Figure 35).

Figure 35

5.29 On construction drawings, it is allowed to apply linear and angular dimensional numbers and inscriptions without leader line shelves.

5.30 If there is not enough space above the dimension line to write the dimension number, then the dimensions are applied as shown in Figure 36; if there is not enough space for drawing arrows, then they are applied, as shown in Figure 37.


Figure 36	Figure 37

The method of applying the dimension number at various positions of the dimension lines (arrows) in the drawing is determined by the greatest ease of reading.

5.31 Dimensional numbers and limit deviations are not allowed to be divided or crossed by any lines of the image. It is not allowed to break the contour line for drawing a dimension number and apply dimension numbers at the intersection of dimension, axial or center lines. In the place where the dimension number is applied, the axial, center lines and hatching lines are interrupted (see figures 38 and 39).


Figure 38	Figure 39

5.32 Dimensions related to the same structural element (groove, protrusion, hole, etc.) are recommended to be grouped in one place, placing them on the image in which the geometric shape of this element is shown most fully (see Figure 40 ).

Figure40

5.33 When applying the size of the radius, a capital letter is placed before the size number R.

5.34 If, when drawing the size of the radius of an arc of a circle, it is necessary to specify the size that determines the position of its center, then the latter is depicted as an intersection of center or extension lines.

With a large radius, the center can be brought closer to the arc, in this case the dimension line of the radius is shown with a break at an angle of 90 ° (see Figure 41).

Figure 41

5.35 If it is not required to indicate the dimensions that determine the position of the center of the circular arc, then the dimension line of the radius may not be brought to the center and shifted relative to the center (see Figure 42).

Figure 42

5.36 When drawing several radii from one center, the dimension lines of any two radii are not located on the same straight line (see Figure 43).

Figure 43

If the centers of several radii coincide, their dimension lines may not be brought to the center, except for the extreme ones (see Figure 44).

Figure 44

5.37 The dimensions of the radii of the outer rounds are applied as shown in Figure 45, the inner rounds - in Figure 46.


Figure 45	Figure 46

Rounding radii, the size of which is not more than 1 mm, are not indicated in the image and their dimensions are applied, as shown in Figure 47.

Figure 47

The method of applying dimension numbers at different positions of the dimension lines (arrows) in the image is determined by the greatest ease of reading. The dimensions of the same radii are allowed to be indicated on a common shelf, as shown in Figure 48.

Figure 48

If the radii of fillets, bends, etc. are the same throughout the graphic document or some radius is predominant, then instead of drawing the dimensions of these radii directly on the image, it is recommended to make entries in the technical requirements: “Rounding radii 4 mm”; "Internal bending radii 10 mm"; "Unspecified radii 8 mm", etc.

5.38 When specifying the size of the diameter (in all cases), the sign "Æ" is applied before the dimension number.

5.39 Before the dimension number of the diameter (radius) of the sphere, the sign Æ is also applied ( R) without the inscription "Sphere" (see Figure 49). If it is difficult to distinguish a sphere from other surfaces in the image, then before the size number of the diameter (radius) it is allowed to put the word “Sphere” or the sign “”, for example, “Sphere Æ18”, “ R 12".

The diameter of the sign of the sphere is equal to the size of the dimensional numbers.

Figure 49

5.40 The dimensions of the square are applied as shown in figures 50 - 52.


Figure 50	Figure 51	Figure 52

The height of the "□" sign must be equal to the height of the dimensional numbers.

5.41 Before the dimension number characterizing the taper, put the sign "", the acute angle of which should be directed towards the top of the cone (see Figure 53).

Figure 53

The sign of the cone and the taper in the form of a ratio should be applied above the center line or on the shelf of the leader line.

5.42 The slope of the surface should be indicated directly at the image of the surface of the slope or on the shelf of the leader line in the form of a ratio (see Figure 54 A), in percent (see Figure 54 b) or in ppm (see Figure 54 V). Before the dimension number that determines the slope, a sign "" is applied, the acute angle of which should be directed towards the slope.

Figure 54

5.43 Marks of levels (height, depth) of a structure or its element from any reference level, taken as "zero" in the view and section, are placed on extension lines (or on contour lines) and are indicated by the sign "¯" made by solid thin lines , stroke length 2 - 4 mm at an angle of 45 ° to the extension line or contour line (see Figure 55a), in the top view they should be applied in a frame directly on the image or on the leader line (see Figure 55 b), or as shown in Figure 55 V.

Figure 55

Level marks are indicated in meters with an accuracy of the third decimal place without indicating the unit of measurement.

5.44 The dimensions of the chamfers at an angle of 45 ° are applied as shown in Figure 56.

Figure 56

It is allowed to indicate the dimensions of a chamfer not shown in the drawing at an angle of 45 °, the size of which on the scale of the drawing is not more than 1 mm, on the shelf of the leader line drawn from the face (see Figure 57).

Figure 57

The dimensions of the chamfers at other angles are indicated according to the general rules - linear and angular dimensions (see Figures 58 A and 58 b) or two linear dimensions (see Figure 58 V).

Figure 58

5.45 The dimensions of several identical elements of the product, as a rule, are applied once, indicating the number of these elements on the shelf of the leader line (see Figure 59 A).

It is allowed to specify the number of elements, as shown in Figure 59 b.

5.47 The dimensions of two symmetrically located elements of the product (except for holes) are applied once without indicating their number, grouping, as a rule, all dimensions in one place (see Figures 63 and 64).

Figure 63

Figure 64

The number of identical holes is always indicated in full, and their dimensions - only once.

5.48 When applying dimensions that determine the distance between evenly spaced identical elements of the product (for example, holes), it is recommended that instead of dimensional chains, apply the size between adjacent elements and the size between the extreme elements as the product of the number of gaps between the elements by the size of the gap (see Figure 65).

Figure 65

5.49 It is allowed not to apply the dimensions of the radius of the arc of a circle of mating parallel lines (see Figure 66).

Figure 66

5.50 With a large number of dimensions drawn from a common base, it is allowed to apply linear and angular dimensions, as shown in Figures 67 and 68, while drawing a common dimension line from the “0” mark and dimension numbers are applied in the direction of extension lines at their ends.


Figure 67	Figure 68

5.51 The dimensions of the diameters of a cylindrical product of a complex configuration can be applied, as shown in Figure 69.

Figure 69

5.52 With a large number of the same type of elements of the product, unevenly located on the surface, it is allowed to indicate their dimensions in the summary table, while using the coordinate method of making holes with their designation in Arabic numerals (see Figure 70) or designate the same type elements in capital letters (see Figure 71 ).

In electronic models of products, the table is placed in the plane of symbols and indications in accordance with GOST 2.052.

Figure 70

Figure 71

5.53 Identical elements located in different parts of the product (for example, holes) are considered as one element if there is no gap between them (see Figure 72 A) or if these elements are connected by thin solid lines (see figure 72 b).

In the absence of these conditions, indicate the total number of elements (see Figure 72 V).

Figure 72

5.54 If the same elements of the product (for example, holes) are located on different surfaces and are shown in different images, then the number of these elements is recorded separately for each surface (see Figure 73).

Figure 73

It is allowed to repeat the dimensions of the same elements of the product or their groups (including holes) lying on the same surface, only if they are significantly removed from each other and are not linked by size (see figures 74 and 75).


Figure 74	Figure 75

5.55 If the graphic document shows several groups of similar holes, it is recommended to mark the same holes with one of the symbols shown in Figure 76.

Other symbols may also be used.

Figure 76

The holes are indicated by symbols on the image, which shows the dimensions that determine the position of these holes.

On construction drawings, it is allowed to outline the same groups of holes with a solid thin line with an explanatory inscription.

5.56 When designating identical holes with symbols, the number of holes and their sizes may be indicated in the table (see Figure 77).

In electronic models of products, the table is placed in the plane of symbols and indications.

Figure 77

5.57 When depicting a part in one projection, the size of its thickness or length is applied, as shown in Figure 78.

Figure 78

5.58 The dimensions of a part or hole of a rectangular section can be indicated on the shelf of the leader line with the dimensions of the sides through the multiplication sign. In this case, in the first place, the size of that side of the rectangle from which the leader line is drawn should be indicated (see Figure 79).

Figure 79

6 Application of dimensional tolerances

6.1 Limit deviations of dimensions should be indicated immediately after the nominal dimensions. Limit deviations of linear and angular dimensions of relatively low accuracy may not be indicated immediately after the nominal dimensions, but stipulated by a general entry in the technical requirements of the drawing, provided that this entry unambiguously determines the values and signs of the maximum deviations.

The general record of the maximum deviations of dimensions with unspecified tolerances should contain the symbols of the maximum deviations of linear dimensions in accordance with for the 14th grade and (or) the accuracy class "medium", are given in table 1.

Note - In the examples, limit deviations are indicated for hole sizes, shaft sizes and dimensions of elements that are not related to holes and shafts.

6.2 Unspecified limit deviations of the radii of roundings, chamfers and corners are not specified separately, they must correspond to those given in GOST 30893.1 in accordance with the quality or accuracy class of the unspecified limit deviations of linear dimensions.

If needed additional guidance general tolerances of linear dimensions, the reference should contain the standard number and the letter designation of the accuracy class, for example, for the accuracy class "medium":

If all limit deviations of linear dimensions are indicated immediately after the nominal dimensions (there is no general record), then the unspecified limit deviations of the radii of roundings, chamfers and corners must correspond to those given in GOST 30893.1 for accuracy classes according to tables 2, 3 and are not specified in the graphic document.

6.3 Limit deviations of linear dimensions indicate symbols tolerance fields in accordance with GOST 25436, for example 18 H 7, 12e 8 or numerical values, for example 18 +0.018, or symbols of tolerance fields with indication of their numerical values in brackets on the right, for example 18 H 7 (+ 0,018) ,

In paper documents, the numerical values \u200b\u200bof limit deviations are allowed to be indicated in the table (see table 2), located in the free field of the drawing.

table 2

In millimeters

When specifying nominal sizes with letter designations, the tolerance fields must be indicated after the dash, for example D - H 11.

6.4 When indicating the maximum deviations by symbols, it is also necessary to indicate their numerical values in the following cases:

a) when assigning maximum deviations (established by standards for tolerances and landings) of sizes not included in the series of normal linear dimensions according to GOST 6636, for example 41.5 H 7 (+0,025) ;

b) when assigning limit deviations, the symbols of which are not provided by GOST 25347, for example, for a plastic part with limit deviations according to GOST 25349 (see Figure 80);

Figure 80

c) when assigning limit deviations for the dimensions of ledges with an asymmetric tolerance field (see figures 81, 82);


Figure 81	Figure 82

6.5 Limit deviations of angular dimensions are indicated only by numerical values (see Figure 83).

Figure 83

6.6 When recording limit deviations with numerical values, the upper deviations are placed above the lower ones. Limit deviations equal to zero are not indicated, for example: 60 +0.19; 60 -0.19 .

With a symmetrical arrangement of the tolerance field, the absolute value of the deviations is indicated once with the “±” sign, while the height of the numbers defining the deviations should be equal to the height of the font of the nominal size, for example, 60 ± 0.23.

6.7 Limit deviations, indicated by numerical values expressed as a decimal fraction, are recorded up to the last significant figure inclusive, equalizing the number of characters in the upper and lower deviations by adding zeros, for example

6.8 The maximum deviations of the dimensions of the parts shown in the assembly drawing are indicated in one of the following ways:

a) in the form of a fraction, in the numerator of which indicate the symbol of the hole tolerance field, and in the denominator - the symbol of the shaft tolerance field, for example - or 50 H 11/h 11 (see figure 84a);

b) in the form of a fraction, in the numerator of which indicate the numerical values of the maximum deviations of the hole, and in the denominator - the numerical values \u200b\u200bof the maximum deviations of the shaft (see Figure 84 b);

c) in the form of a fraction, in the numerator of which indicate the symbol of the tolerance field of the hole, indicating its numerical value in brackets on the right, and in the denominator - the symbol of the shaft tolerance field, indicating its numerical value in brackets on the right (see Figure 84 V);

Figure 84

d) in the form of a record in which the maximum deviations of only one of the mating parts are indicated. In this case, it is necessary to explain to which part these deviations relate (see Figure 85).

Figure 85

6.9 When different limit deviations are assigned for surface sections with the same nominal size, the boundary between them is drawn with a solid thin line, and the nominal size is indicated with the corresponding limit deviations for each section separately (see Figure 86).

The boundary line between the areas should not be drawn through the shaded part of the image (see Figure 87).

Figure 87

6.10 If it is necessary to limit fluctuations in the size of identical elements of one part within a part of the tolerance field (see Figure 88a) or it is necessary to limit the value of the accumulated error in the distance between repeating elements (see Figure 88 b), then these data are indicated in the technical requirements.

Figure 88

6.11 If it is necessary to indicate only one limit size (the second is limited upward or downward by some condition), then max or min are indicated after the size number, respectively (see Figure 89).

Figure 89

It is also allowed to indicate the limiting dimensions on the assembly drawings for gaps, tightness, backlash, etc., for example, "Maintain the axial displacement of the cam within 0.6 - 1.4 mm."

6.12 Limit deviations of the location of the axes of the holes can be specified in two ways:

a) positional tolerances of the axes of the holes in accordance with the requirements of GOST 2.308;

b) limit deviations of the dimensions that determine the position of the axes (see figures 90 - 92).

Figure 90

If the tolerances for the location of the axes are dependent, then after the maximum deviations of the dimensions that determine the position of the axes, the sign of the dependent tolerance should be indicated.

Keywords: design documentation, dimensions, limit deviations

DIMENSIONING
AND MAXIMUM DEVIATIONS

GOST 2.307-68
(ST SEV 1976-79, ST SEV 2180-80)

STATE STANDARD OF THE UNION OF THE SSR

Unified system of design documentation

APPLICATION OF DIMENSIONS AND MAXIMUM DEVIATIONS

Unified system for design documentation.
Drawing of dimensions and limit deviations

GOST
2.307-68

(ST SEV 1976-79,
ST SEV 2180-80

Introduction date 01.01.71

This standard establishes the rules for applying dimensions and limit deviations on drawings and other technical documents for products of all industries and construction.

(Revised edition, Rev. No. 3).

1. BASIC REQUIREMENTS

The exception is the cases provided for in GOST 2.414-75; GOST 2.417-78; GOST 2.419-68, when the size of the product or its elements is determined from images made with a sufficient degree of accuracy.

The basis for determining the required accuracy of the product during manufacture is the maximum deviations of dimensions indicated on the drawing, as well as the maximum deviations of the shape and location of surfaces.

1.2. The total number of dimensions in the drawing should be minimal, but sufficient for the manufacture and control of the product.

1.3. Dimensions that are not subject to execution according to this drawing and are indicated for greater ease of use of the drawing are called reference.

1.4. Reference dimensions in the drawing are marked with a “*”, and in the technical requirements they write: “* Dimensions for reference”. If all dimensions on the drawing are for reference, they are not marked with an “*”, but in the technical requirements they write: “Dimensions for reference”.

On construction drawings, reference dimensions are noted and specified only in cases provided for in the relevant documents approved in the prescribed manner.

a) one of the sizes of a closed dimensional chain. Limit deviations of such dimensions are not indicated in the drawing (dev.);

a) when specifying the size of the diameter of the circle, regardless of whether the circle is shown in full or in part, while the break of the dimension line is made further than the center of the circle (Fig.);

A general record of maximum deviations of dimensions with unspecified tolerances must contain symbols for maximum deviations of linear dimensions in accordance with (for deviations by quality) or according to GOST 25670-83 (for deviations, by accuracy classes). Symmetrical limit deviations, assigned by qualifications, should be denoted indicating the qualification number.

The designations of one-sided limit deviations for qualifications assigned only for round holes and shafts (option 4 according to GOST 25670-83) are supplemented with a diameter sign (Æ ).

Examples of general records corresponding to options according to GOST 25670-83 for grade 14 and (or) accuracy class "average" are given in Table. :

Table 1

	Legend notation example
	H 14, h 14 or H 14, h 14,
	+ t2, - t2,
	Or
	Æ H 14, Æ h 14 orÆ H 14, Æ h 14,

All images are accompanied by drawing dimensions. When applying dimensions, one should be guided by the main provisions of GOST 2.307-2011 "Dimensioning and limit deviations".

The basis for determining the size of the depicted product and its elements are the dimensional numbers indicated in the graphic document. The numerical value of the size to be entered must correspond to its natural value (actual value), regardless of the accepted scale of the image. On the training drawings, only the nominal values \u200b\u200bof dimensions are applied without indicating their maximum deviations.

Linear dimensions are indicated on the drawing in millimeters without indicating the unit of measurement, angular dimensions - in degrees, minutes.

Dimensions in graphic documents are indicated by dimensional numbers and dimension lines.

When applying the size of a straight segment, the dimension line is drawn parallel to this segment, the extension lines are perpendicular to the dimension lines (Fig. 7).

Rice. 7. Rules for setting dimensions on the drawing

Dimension lines are preferably drawn outside the outline of the image. It is not allowed to use contour lines, axial, center and extension lines as dimension lines. It is necessary to avoid the intersection of dimension and extension lines. The dimension line at both ends is limited by arrows resting on the extension lines. The shape of the arrow and the approximate ratio of the sizes of its elements are shown in fig. 8.

Rice. 8. The image of the arrows in the drawing

Extension lines are drawn from the lines of the visible contour. The extension lines should extend beyond the ends of the arrows of the dimension line by 1 ... 5 mm.

The distance between the contour line and the dimension line is selected depending on the size of the image and the saturation of the drawing. The minimum distance between the dimension line and the contour line should be 10 mm, and the minimum distance between parallel dimension lines should be 7 mm.

Dimensional numbers are applied above the dimension line as close as possible to its middle. When applying several parallel dimension lines, the dimension numbers should be staggered (Fig. 7).

If there is not enough space for drawing arrows and dimensional numbers, then they are applied using one of the methods shown in Fig. 9. If there is not enough space for arrows on dimension lines located in a chain, it is allowed to replace the arrows with serifs 1-3 mm long, applied at an angle of 45 ° to the dimension lines or clearly marked points (Fig. 9). If there is not enough space for an arrow due to a closely spaced contour or extension line, the latter can be interrupted.

Rice. 9. Dimension lines

Dimensional numbers are not allowed to be divided or crossed by any lines of the drawing. In the place where the dimension number is applied, the axial, center lines and hatching lines are interrupted (Fig. 10).

Dimensions related to the same structural element (groove, protrusion, hole, etc.) are recommended to be grouped in one place, placing them on the image in which the geometric shape of this element is shown most fully (Fig. 11).

Rice. 11. Size grouping

When drawing the size of the arcs, indicate its radius, for a circle - the diameter. Before the dimensional number of the radius, an uppercase Latin letter " R» , (For example, R20 ), before the dimension number of the diameter - the sign "" (for example,  20 ).

In the case of making an image of a part with a spherical surface, if it is difficult to distinguish it from other surfaces, it is allowed to apply the word “Sphere” or the sign “” when applying the size of the diameter (radius), sphere (for example, SphereR15 or 40 ).

The square in the drawing is determined by two sizes of its sides or one size with the sign "" (Fig. 12). Diagonals on the edge of the element, drawn by thin lines, conditionally designate a plane.

The dimensions of the chamfers at an angle of 45º are applied as shown in Figure 12 A. The chamfer width and angle are combined into one dimension using the "×" sign.

The dimensions of the chamfers at other angles are indicated separately by linear and angular dimensions (in Fig. 12 A so the chamfer dimensions are indicated at an angle of 30º with a chamfer width of 3 mm) or two linear dimensions (Fig. 12 b).

Rice. 12 A Rice. 12 b

If a view or section of a symmetrical object or individual symmetrically located elements is depicted only up to the axis of symmetry or with a break, then the dimension lines related to these elements are drawn with a break, and the break of the dimension line is made further than the axis or break line of the object (Fig. 13).

Rice. 13. Dimensioning with a break

The total number of dimensions should be minimal, but sufficient for the manufacture and control of the product. The dimensions of the same element in the drawing are not allowed to be repeated. The dimensions of several identical elements of the product, as a rule, are applied once with an indication of the number of these elements on the shelf of the leader line or under it (Fig. 14). At the same time, for elements evenly spaced around the circumference (for example, holes), the angular dimensions between them are not set, provided that one of these elements lies on one of the axes of symmetry (Fig. 14 A). Only the size of the diameter of the circle on which the centers of the holes are located in fig. 14 A. If none of the holes lies on the axis of symmetry, then you should set the angle to the first element (Fig. 14 b).

Rice. 14 A Rice. 14 b

284 570

ESKD GOST 2.307-68 Application of dimensions and maximum deviations

In order to rationally apply and correctly read the dimensions, it is necessary to study some of the conventions established by GOST 2.307-68 "Application of dimensions and maximum deviations". Consider some of the main provisions of this standard and recommendations of reference and educational literature:

Primary requirements

Dimensioning

Application of limit deviations

Primary requirements

To determine the size of the depicted product and its elements, the dimensional numbers printed on the drawing are used.

The required accuracy of the product during manufacture is set by indicating on the drawing the maximum deviations of dimensions, as well as the maximum deviations of the form and The total number of dimensions in the drawing should be minimal, but sufficient for the manufacture and control of the product.

Reference dimensions in the drawing are marked with a “*”, and in the technical requirements they write: “* Dimensions for reference”. If all the dimensions in the drawing are for reference, they are not marked with a “*” sign, but in the technical requirements they write: “Dimensions for reference”.

On the drawings of products for dimensions, the control of which is technically difficult; put the sign "*", and in the technical requirements they put the inscription "Dimensions of providing. instr.". The indicated inscription means that the fulfillment of the size specified by the drawing with the maximum deviation must be guaranteed by the size of the tool or the corresponding technological process.

It is not allowed to repeat the dimensions of the same element in different images, in technical requirements, in the main inscription and in the specification. The exception is the reference dimensions (transferred from the drawings of blanks, the dimensions of parts (elements) from long, shaped, sheet and other rolled products).

The linear dimensions and their marginal deviations in the drawings and specifications are indicated in millimeters, without indicating the unit of measurement. If the dimensions on the drawing must be indicated not in millimeters, but in other units of measurement (centimeters, meters, etc.), then the corresponding dimensional numbers are recorded with the designation of the unit of measurement (cm, m) or indicated in the technical requirements.

For dimensions and maximum deviations given in the technical requirements and explanatory inscriptions on the drawing field, the units of measurement must be indicated.

Angular dimensions and limit deviations of angular dimensions are indicated in degrees, minutes and seconds with the designation of the unit of measurement, for example: 4 °; 4°30?; 12°50?30??; 0°30?40??; 0°18?; 0°5?25??; 0°0?30??; 30°±1°; 30°±10?.

For dimensional numbers, simple fractions are not allowed, with the exception of sizes in inches.

The dimensions that determine the location of the mating surfaces are, as a rule, affixed from the structural bases, taking into account the possibilities of performing and controlling these dimensions.

When the elements of the object (holes, grooves, teeth, etc.) are located on the same axis or on the same circle, the dimensions that determine their relative position are applied in the following ways:

from a common base (surface, axes) - fig. 2a and b;by setting the sizes of several groups of elements from several common bases- fig.3;setting dimensions between adjacent elements (chain) - Fig.4.

Figure 3. Setting the dimensions of several groups of elements from several bases

Figure 4. Dimensioning between adjacent elements (chain)

Dimensions on the drawings are not allowed to be applied in the form of a closed chain, unless one of the dimensions is indicated as a reference.
Dimensions that determine the position of symmetrically located surfaces of symmetrical products are applied as shown in Figures 5 and 6.

Figure 5. An example of setting dimensions that determine the position of symmetrically located surfaces for symmetrical products

Figure 6. An example of setting dimensions that determine the position of symmetrically located surfaces for symmetrical products

For all dimensions printed on the working drawings, limit deviations are indicated.
It is allowed not to indicate limit deviations:

a) for dimensions that define zones of different roughness of the same surface, heat treatment zones, coating, finishing, knurling, notches, as well as diameters of knurled and notched surfaces. In these cases, a sign is applied directly to such dimensions? ;
b) for the dimensions of the parts of products of a single production set with an allowance for fit.

On such drawings, in the immediate vicinity of the indicated dimensions, the sign "*" is applied, and in the technical requirements they indicate:

“* Sizes with a fit allowance up to det. ……..”,
“* Dimensions with an allowance for fit according to hell. ……..”,
"*Dimensions with an allowance for fit on the mating part."

Dimensioning

For drawing dimensions, extension and dimension lines and dimension numbers are used (Fig. 7).

Figure 7. Dimension components

Dimension and extension lines should be made with solid thin lines. Dimension lines are limited by arrows. The size of the arrows is selected depending on the thickness S of the line of the visible contour of the object (Fig. 8) and should be approximately the same for all dimension lines of the drawing.

When applying the size of a straight segment, the dimension line is drawn parallel to this segment, and the extension lines are perpendicular to the dimensions (Fig. 9).

When applying the dimensions of parts similar to the one shown in Figure 10, the dimension lines should be drawn in the radius direction, and the extension lines along the arcs of circles.

Figure 10. An example of a part in which dimension lines should be drawn in the radius direction, and extension lines along arcs of circles

When applying the size of the corner, the dimension line is drawn in the form of an arc with a center at its apex, and extension lines are drawn radially (Fig. 11).
When applying dimensions, it must be remembered that all drawings, regardless of scale, indicate the actual dimensions of the product.

Figure 11. An example of applying the size of the corner

Dimensional numbers within one drawing are performed in a font of the same size.

Dimensional numbers are applied above the dimension line as close as possible to its middle. When applying several parallel or concentric dimension lines at a small distance from each other, it is recommended that the dimension numbers above them be staggered (Fig. 16).

When applying the size of the diameter inside the circle, the dimension numbers are shifted relative to the middle of the dimension lines.

Dimensional numbers of linear dimensions with different slopes of the dimension lines are arranged as shown in Figure 12. If it is necessary to apply a dimension in the shaded area, the corresponding dimension number is applied on the shelf of the leader line (Fig. 13).

Angular dimensions are applied as shown in Figure 14. In the area located above the horizontal center line, the dimension numbers are placed above the dimension lines from the side of their convexity; in the area located below the horizontal center line - from the side of the concavity of the dimension lines. It is not recommended to apply dimensional numbers in the shaded area. In this case, the dimension numbers indicate on horizontally applied shelves (Fig. 15).

The arrows limiting the dimension lines should rest with their tip against the corresponding contour lines, or extension, or axial lines.

The extension lines should extend beyond the ends of the dimensional arrows by 1 ... 5 mm (Fig. 16).

The minimum distance between parallel dimension lines should be 7 mm, and between the dimension line and the contour line - 10 mm and are selected depending on the size of the image and the saturation of the drawing (Fig. 16).

Figure 16 Dimensioning Requirements

In the cases shown in Figure 17, the dimension and extension lines are drawn so that they, together with the measured segment, form a parallelogram.
Avoid crossing dimension and extension lines.

It is not allowed to use contour lines, axial, center and extension lines as dimension lines.

It is allowed to draw dimension lines directly to the lines of the visible contour, axial, center and other lines.

Figure 17. An example of applying a dimension, when the dimension and extension lines are drawn so that they, together with the measured segment, form a parallelogram

Extension lines are drawn from the line of the visible contour, except for cases when, when applying dimensions on an invisible contour, there is no need to draw an additional image. If a view or section of a symmetrical object or individual symmetrically located elements is depicted only up to the axis of symmetry or with a break, then the dimension lines related to these elements are drawn with a break, and the break of the dimension line is made further than the axis or break line of the object (Fig. 18).

Figure 18. An example of applying a dimension with a broken dimension line

Dimension lines can be drawn with a break in the following cases:
a) when specifying the size of the diameter of the circle, regardless of whether the circle is shown in full or in part, while the break in the dimension line is made further than the center of the circle (Fig. 19);
b) when applying dimensions from a base not shown in this drawing (Fig. 20).


Figure 19. An example of drawing the diameter of a circle	Figure 20. An example of applying a dimension from a base not shown in this drawing

When depicting a product with a break, the dimension line is not interrupted (Fig. 21)

Figure 21. Dimensioning when depicting a product with a gap

If the length of the dimension line is insufficient to place arrows on it, then the dimension line continues to be extended beyond the extension lines (or, respectively, beyond the contour, axial, center, etc.) and the arrows are applied, as shown in Fig. 22.

Figure 22. An example of drawing dimension lines

If there is not enough space for arrows on dimension lines located in a chain, it is allowed to replace the arrows with serifs applied at an angle of 45 ° to the dimension lines or clearly marked points.
If there is not enough space for an arrow due to a closely spaced contour or extension line, the latter can be interrupted.

If there is not enough space above the dimension line to write the dimension number, then the dimensions are applied as shown in Fig. 23; if there is not enough space for drawing arrows, then they are applied, as shown in fig. 24.

Figure 23. Examples of applying dimension numbers

Figure 24. Examples of applying dimension numbers

The method of applying the dimension number at different positions of the dimension lines (arrows) in the drawing is determined by the greatest ease of reading.

Dimensional numbers and limit deviations are not allowed to be divided or crossed by any lines of the drawing.

It is not allowed to break the contour line for drawing a dimension number and apply dimension numbers at the intersection of dimension, axial or center lines.

In the place where the dimension number is applied, the axial, center lines and hatching lines are interrupted (Fig. 25 and 26).


Figure 25. Dimensioning a hatch	Figure 26. Dimensioning example

Figure 27. Applying dimensions related to the same structural element

When applying the size of the radius, a capital letter R is placed in front of the dimension number.
If, when applying the size of the radius of an arc of a circle, it is necessary to specify the size that determines the position of its center, then the latter is depicted as an intersection of center or extension lines.

With a large radius, the center can be brought closer to the arc, in this case the dimension line of the radius is shown with a break at an angle of 90 ° (Fig. 28).

If it is not required to specify the dimensions that determine the position of the center of the circular arc, then the dimension line of the radius may not be brought to the center and shifted relative to the center (Fig. 29).

When drawing several radii from one center, the dimension lines of any two radii are not located on the same straight line (Fig. 30a). If the centers of several radii coincide, their dimension lines may not be brought to the center, except for the extreme ones (Fig. 30b).

The dimensions of the radii of the outer roundings are applied, as shown in Fig. 31, internal fillets - in fig. 32.

Rounding radii, the size of which is 1 mm or less on the scale of the drawing, are not shown in the drawing and their dimensions are applied as shown in Fig. 33.

The method of applying dimensional numbers at different positions of the dimension lines (arrows) in the drawing is determined by the greatest readability. The dimensions of the same radii are allowed to be indicated on a common shelf, as shown in fig. 34.

If the radii of roundings, bends, etc. are the same throughout the drawing or some radius is predominant, then instead of drawing the dimensions of these radii directly on the image, it is recommended to make an entry in the technical requirements like: “Rounding radii 4 mm”; "Internal bending radii 10mm"; "Unspecified radii 8 mm", etc.

When specifying the size of the diameter (in all cases), the sign “? ".
Before the dimension number of the diameter (radius) of the sphere, the sign “? ” (R) without the inscription “Sphere” (Fig. 35).

If it is difficult to distinguish a sphere from other surfaces in the drawing, then before the size number of the diameter (radius) it is allowed to put the word “Sphere” or the sign “? ”, for example, “Sphere? 18, ? R12".
The diameter of the sign of the sphere is equal to the size of the dimensional numbers in the drawing.

Figure 35. An example of applying the size of a sphere

The dimensions of the square are applied as shown in Figure 36. The height of the “ ” sign must be equal to the height of the dimensional numbers in the drawing.

Figure 36. An example of applying the size of a square

Before the dimension number characterizing the taper, the sign "" is applied, the acute angle of which should be directed towards the top of the cone (Fig. 37).
The sign of the cone and the taper in the form of a ratio should be applied above the center line or on the shelf of the leader line.

Figure 37. An example of applying the size of the taper

The slope of the surface should be indicated directly at the image of the slope surface or on the shelf of the leader line as a ratio (Fig. 38a), in percent (Fig. 38b) or in ppm (Fig. 38c). Before the dimension number that determines the slope, put the sign "

Marks of levels (heights, depths) of a structure or its element from any reference level, taken as "zero" in the view and section, are placed on extension lines (or on contour lines) and denoted by the sign "? ”, made by solid thin lines, the length of the strokes is 2-4 mm at an angle of 45 ° to the extension line or contour line (Fig. 39a), in the top view they should be applied in a frame directly on the image or on the leader line (Fig. 39b) , or as shown in Figure 39c. Level marks are indicated in meters with an accuracy of the third decimal place without indicating units of measurement.


A)	b)	V)
Figure 39. An example of applying a level mark

The dimensions of the chamfers at an angle of 45 ° are applied, as shown in Fig. 40a.
It is allowed to indicate the dimensions of a chamfer not shown in the drawing at an angle of 45 °, the size of which on the scale of the drawing is 1 mm or less, on the shelf of the leader line drawn from the face (Fig. 40b).

1 area of ​​use