1、DC 774.43 : 001.4 DEUTSCHE NORM December 1992 Eng i nee ring draw i ng practice I DIN Dimensioning Concepts and general principles 406 Part i0 Technische Zeichnungen: MaBeintragung; Begriffe, allgemeine Grundlagen This standard supersedes April 1977 edition of DIN 406 Part 1 and, together with Decem
2、ber 1992 edition of DIN 406 Parts 11 and 12, supersedes August 1981 edition of DIN 406 Part 2. See Explanatory notes for connection with International Standard IS0 129: 1985 published by the International Organization for Standardization (/SO). Contents 1 Scope and field of application . 2 Concepts
3、3.1 Dimensioning elements 3.2 Symbols 3.3 Dimensioning systems . 3.4 Orientation of drawing and lettering . 3 General principles 3.5 Application . Page . 1 . 1 . 2 . 2 . 2 . 4 . 4 . 4 1 Scope and field of application This standard specifies concepts and general principies relating to dimensioning on
4、 engineering drawings. The spec- ifications may be applied analogously to dimensioning on other technical documents. Further details and practical examples are provided in other parts of the DIN 406 series of standards. 2 Concepts In the definitions given below, an arrow (+) precedes terms which are
5、 themselves defined elsewhere in this clause. 2.1 Dimensioning from a common feature Dimensioning from a common feature is a method in which a number of features are dimensioned from a common fea- ture (.e. where a number of dimensions of the same direc- tion relate to a common origin). The dimensio
6、ns are based on the theoretically exact shape of the common feature. 2.2 Datum A datum is a dimension of a feature which refers to another given feature of the same object (datum feature). 2.3 Single dimensioning In single dimensioning, the features are individually dimen- sioned without reference t
7、o a common feature. 2.4 Finished dimension A finished dimension is a - dimension which refers to the object as an end product. NOTE: The representation of the object as an end product may refer to the raw (e.g. as formed), inter- mediate or finished state of the object, or even to a surface treatmen
8、t. Page Standards referred to 5 Other relevant standards . 5 Previous editions 5 Amendments 5 Explanatorynotes 5 Alphabetical index . 6 2.5 Functional dimension A functional dimension is a -+ dimension serving to define the shape, size or orientation of features, or the spaces between them, which ar
9、e essential to the function of a part or group of parts. 2.6 Initial length The initial length is the length of a part prior to its being bent. 2.7 Auxiliary dimension An auxiliary dimension is a - dimension given for information purposes only and not essential to the geometrical defini- tion of a p
10、art. It does not count as a dimensional specifica- tion for contractual purposes. 2.8 Leader line A leader line used to indicate + dimensions is a line connect- ing the representation of an object and a dimensional value and is generally drawn as a line extending obliquely out of the representation.
11、 2.9 Informative dimension An informative dimension is a - dimension which is indicated in tender, sales and advertising documentation and in other technical documents. It is generally not specifically identi- fied as such, is not toleranced and only counts as a dimen- sional specification for contr
12、actual purposes when this has been expressly agreed between the contracting parties. NOTE: If, in a given document, informative dimen- sions need to be distinguished from other dimen- sions, they may be identified as such (e.g. by a lower-case i in a circle being placed next to them). Continued on p
13、ages 2 to 6 puth Verlag GmbH, Berlin. has the exclusive right of sale for German Standards (DIN-Normen). DIN 406 Part 70 Engl. Price group 7 12.93 Sales No.0107 Page 2 DIN 406 Part 10 2.10 Chain dimensioning In chain dimensioning, single dimensions are indicated con- secutively. 2.11 Dimensioning by
14、 coordinates Dimensioning by coordinates is a form of + dimensioning from a common feature within a system of (Cartesian or polar) coordinates. 2.12 Dimension A dimension is a physical quantity defined by a numerical value and a unit of measurement. The dimensions in this standard are linear dimensi
15、ons, which are indicated in units of length, and angular dimensions, indicated in units of angle. 2.13 Dimensioning by tables In dimensioning by tables, the parts and/or features andior dimensions are identified by digits or letters, which are entered in tables together with the corresponding + dime
16、nsional values. 2.14 Projection line A projection line is a line drawn to connect the feature to be dimensioned to the associated + dimension line. 2.15 Dimension line A dimension line is a straight or curved line running between two edges, between an edge and a - projection line, or between two .+
17、projection lines. Where drawings andior dimensioning are simplified, the dimension line may terminate at only one of the features referred to. 2.16 Termination A termination is a marker on a +dimension line that indicates where the line ends. 2.17 Centre line A centre line is a line that defines the
18、 geometrical centre of features in drawings. 2.18 Parallel dimensioning Parallel dimensioning is a form of + dimensioning from a common feature in which the features are individually dimensioned by way of dimension lines drawn parallel or concentric to each other. 2.19 Check dimension A check dimens
19、ion is a + dimension designated as requiring particular consideration when the scope or stringency of inspection is specified. 2.20 Raw dimension A raw dimension is a - dimension which refers to the initial geometry of an object. 2.21 Line of symmetry A line of symmetry identifies the plane of symme
20、try which divides an object notionally into two symmetrical halves. 2.22 Superimposed running dimensioning Superimposed running dimensioning is a form of -dimension- ing from a common feature in which each feature is dimen- sioned from a common origin with the dimensional values being given in ascen
21、ding progression. The + dimension lines are generally placed as a superimposed series. 2.23 Repetition For the purposes of this standard, repetition is the regular recurrence of features at equal intervals or angles which are assigned to one or more common datum features (also ter- med repetetive fe
22、atures). 2.24 Theoretically exact dimension A theoretically exact dimension is a- dimension used to indi- cate the geometrically ideal (theoretically exact) orientation or form of a dimensioned feature. 2.25 Pre-work dimension A pre-work dimension is a + dimension which defines an intermediate state
23、 during the processing of a feature (e.g. the - dimension prior to grinding or coating). 2.26 Other concepts For definitions of actual size, nominal size, tolerance and fit, see IS0 286 Part 1. For definitions of datum, datum feature and datum sys- tem, see IS0 5459 and for the definition of origins
24、, see ISOIDIS 10 209 Part 2. For definitions relating to drawings, see DIN 199 Part 1, and for those associated with components, assembly units, etc., DIN 199 Part 2. 3 General principles 3.1 Dimensioning elements The elements used in dimensioning are: - dimension lines; - projection lines; - termin
25、ations; - dimensional values; - dimensional values with symbol for tolerance class; - dimensional values with limits of size; - units of measurement; - markers as specified in subclause 3.2; - leader lines. Line widths shall be as specified in DIN 15 Parts 1 and 2. 3.2 Symbols 3.2.1 Arrowhead The ar
26、rowhead is a termination in the form of an isosceles triangle - with an included angle of 15 and a length of ten times - with an included angle of 900 and a length of four the width of the dimension line, or times the width of the dimension line. - - t Arrowheads are placed at the ends of the dimens
27、ion or leader lines with their tips ending on the associated projec- tion line or outline. 3.2.2 Oblique stroke The oblique stroke is a termination running from bottom left to top right at an angle of 45O to the lay of the drawing, with a length of 12 times the width of the dimension line. The centr
28、e of the oblique stroke passes through the intersection of dimension line, projection line or feature outline 1). 1) The specifications 2.14 and 2.15 in this drawing and the following drawings are references to the corresponding subclauses in clause 2. DIN 406 Part 10 Page 3 3.2.3 Dot The dot is a d
29、imension line termination which has a diame- ter 5 times the width of the wider of the lines to which it is assigned. The centre of the dot shall be placed on the inter- section of dimension line and projection line or feature out- line. 3.2.4 Circle 3.2.4.1 The dot used as a dimension line terminat
30、ion may also be drawn as a circle. 3.2.4.2 lhe circle used to indicate the origin is a dimension line termination which is 8 times the width of the wider of the two intersecting lines. The centre of the circle shall be placed on the intersection of dimension line and the line of the datum feature. 3
31、.2.4.3 A circle from the bottom of which a tangent is drawn horizontally, ending in an arrowhead, is a graphical symbol that is used instead of the written indication initial length and is always placed before the dimensional value of the initial length. This circle has a diameter equal to ten times
32、 the line width of the lettering. The length of the line with the arrowhead is equal to 1,5 times the diameter of the circle (arrowhead: leg angle of 15O, length ten times the line width of the lettering). 3.2.4.4 The circle used to indicate the origin signifies, when combined with a datum indicatio
33、n (cf. IS0 5459), that the specified datum is the origin of a dimensional system. El 3.2.5 Triangle 3.2.5.1 The right-angled triangle is a graphical symbol which is used instead of the written indication slope. The orientation of the triangle is determined by the shape of the part at the point where
34、 it slopes (cf. figure 88 in DIN 406 Part 11, December 1992 edition). The triangle is always placed before the dimensional value of the slope and has a leg ratio of 1 : 2 (length: 16 times line width of lettering). 3.2.5.2 For the graphical symbol used to indicate the fea- tures cone and taper (heig
35、ht of triangle: 16 times line width of lettering; ratio of base to height: 1 : 2) (see figure 2 in IS0 3040). 3.2.5.3 See figure 17 in IS07083 for graphical symbols used to indicate datums. 3.2.6 Frames 3.2.6.1 A frame consisting of two parallel lines set a dis- tance twice the height of the letteri
36、ng apart and connected at each end by semicircles is used to identify check dimen- sions. The frame may, where necessary, be divided into fields by vertical lines. 3.2.6.2 See figure 19 in IS0 7083 for the frame to be used for theoretically exact dimensions. 3.2.6.3 See figures 22 and 23 in IS0 7083
37、 for the frame to be used for geometrical tolerances. 3.2.7 Underlining An underlining is a straight thin continuous line drawn beneath the dimensional value. Unterlining is used to iden- tify dimensional values which differ in scale from the scale applying to the other dimensions in a drawing. This
38、 symbol is not to be used in computer assisted drawings. - 3.2.8 Round brackets 2) Round brackets are used to indicate auxiliary dimensions or supplementary indications, e.g. supplementary indications near the title block. o 3.2.9 Square brackets 2) Square brackets are used to indicate raw and pre-w
39、ork dimensions in drawings of assembly parts. They are also used for dimensions on parts which must be preserved as finished dimensions for the next highest stage of manufac- ture (e.g. finished bush in welded assembly). I 3.2.10 Curly brackets Curly brackets are used to enclose groups of related in
40、dica- tions. o 3.2.11 Square 2) A square is a graphical symbol which is used together with the dimensional value of the side length to indicate that the feature concerned is a square of that size. o 1) The specifications 2.14 and 2.15 in this drawing and the following drawings are references to the
41、corresponding subclauses in clause 2. 2) See DIN 6776 Part 1 for size. Page 4 DIN 406 Part 10 3.2.12 Circle with oblique stroke 2) A circle with an oblique stroke is a graphical symbol used to indicate a diameter. 3.2.13 Letter R 2) The dimensional values of radii are identified by a capital R being
42、 placed in front of them. R 3.2.14 Letter S 2) The dimensional values of spherical features are additionally identified by a capital S being placed in front of the diame- ter symbol or of the capital R. SR S 3.2.15 Letters SW 2) The dimensional values of widths across flats are identified by the cap
43、itals letters SW being placed in front of them. sw 3.2.16 Semi-circle/curve symbol The dimensional values of curve lengths are identified by a semi-circle (diameter: 14 times line width of lettering) pre- ceding the dimensional value. n Where the drawing is prepared manually, a modified curve symbol
44、 may be placed above the dimensional value of the curve length. - 3.2.17 Symmetry symbol A symmetry symbol consists of two parallel thin continuous lines which are placed at right angles to, and axially on, the ends of a line of symmetry, their minimum length being 5 mm. il- 3.2.18 Other symbols Oth
45、er symbols (e.g. those specified in DIN 1302 or DIN 5473) may also be used. Such symbols shall be exe- cuted in accordance with the standardized rules of lettering and drawing. 3.3 Dimensioning systems The objects represented may be dimensioned and toler- anced with reference to their function, thei
46、r production, or to the criteria of inspection. In a given drawing, more than one such system of dimen- sioning may be used concurrently. 3.3.1 Dimensioning for function Dimensioning for function is characterized by the selection, indication and tolerancing of dimensions being undertaken exclusively
47、 on the basis of design criteria aimed at ensuring that the parts of a product will combine smoothly so as to permit the product to fulfil its intended function. The manufacturing and inspection conditions are not taken into account. 3.3.2 Dimensioning for production Dimensioning for production is c
48、haracterized by the dimen- sions directly required for production purposes being calcu- lated from the functional dimensions, indicated in the draw- ing and toleranced as a function of the functional dimen- sions so as to meet manufacturing requirements. Dimensioning for production is a function of
49、the particular production method. 3.3.3 Dimensioning for inspection Dimensioning for inspection is characterized by the dimen- sions and dimensional tolerances being indicated in the drawing to suit the requirements of the intended inspection. Dimensioning for inspection purposes is a function of the particular inspection procedure. 3.4 Orientation of drawing and lettering 3.4.1 The orientation of the drawing shall correspond to the reading direction of the title block. 3.4.2 All dimensions, graphical symbols and written speci- fications shall preferably
