1、GM DAEWOO Auto & Technology EDS Engineering, GM DAEWOO Auto & Technology Standards LINEAR AND ANGULAR DIMENSIONS Do Not Use on New Programs. Being Replaced by Global Design Standards EDS-A-1103 ISSUED DATE: 1996. 03. 19 REVISED DATE: 2008. 05. 31 VERSION: 3 (Superceded) EDS-A-1103LINEAR AND ANGULAR
2、DIMENSIONS PAGE: 1/18 ISSUED DATE: 1996. 03. 19 REVISED DATE: 2008. 05. 31 VERSION: 3 GM DAEWOO Auto & Technology Note: This standard may be applied only for current project drawings generated by CATIA. It is Superceded for all future projects and replaced by Global Design Standards. 1. PURPOSE This
3、 standard aims at determining standards based on which to correctly and effectively indicate dimensions on drawings to deliver information on product size in a clear manner. 2. SCOPE This standard describes methods of entering dimensions in all drawings prepared and controlled by GM DAEWOO Auto & Te
4、chnology Company (hereinafter referred to as the “GMDAT“). 3. PRINCIPLES OF DIMENSIONING 3.1. Dimensions shall be those of complete products which have gone through final finishing. When other dimensions are entered, separate indication shall be made. 3.2. Optimum dimensions necessary for precisely
5、expressing the shape of the product shall be entered clearly. 3.3. Dimensions shall not be duplicated in other views as long as possible. 3.4. Dimensions that may cause various interpretation shall not be used. 3.5. In case of difference between measured and entered dimensions, the entered ones prev
6、ail. In any case, however, drawings shall be made correctly as long as possible. 3.6. Dimensions shall be properly spaced so as to avoid misreading and curtail time to figure out the contents. 3.7. Dimensions shall be entered in the order of points, lines, and plan, which serve as basis of manufactu
7、ring and inspection. 3.8. Dimensions shall be so entered as to avoid separate calculation. 3.9. Related dimensions shall be entered collectively at a proper place. 3.10. Reference dimensions shall be entered with parenthesis. 4. COMPOSITION OF DIMENSIONS 4.1. Dimension line This line, which suppleme
8、nts the dimensions of a product, is drawn parallel with the outline of the product using the line specified in EDS-A-1011. EDS-A-1103LINEAR AND ANGULAR DIMENSIONS PAGE: 2/18 ISSUED DATE: 1996. 03. 19 REVISED DATE: 2008. 05. 31 VERSION: 3 GM DAEWOO Auto & Technology 4.2. Extension line 4.2.1. This li
9、ne connects ends of the dimension line and outline to indicate specified range of the dimension value using the line specified in EDS-A-1011. 4.2.2. The extension line is extended about 2mm from the dimension line, and there may be some space between it and the outline. 4.3. Dimension limit symbol 4
10、.3.1. It is drawn at the end of the dimension line, and an arrowhead is used to indicate its limit. When the arrowhead cannot be drawn, a small filled-in circle is used. 4.3.2. The size of the arrowhead and the circle shall conform to Table 4.1. 4.4. Dimension value 4.4.1. It represents the complete
11、d dimensions and is drawn about 1mm off from the dimension line. 4.4.2. The unit of length is mm when not indicated. Units other than mm shall always be separately indicated. The angle is based on degree, which is used in combination with minute and second. 4.4.3. The letter size of dimension values
12、 shall conform to EDS-A-1006. The decimal point shall be at the bottom, and the comma shall not be used even in case of several decimal places exceeding three EDS-A-1103LINEAR AND ANGULAR DIMENSIONS PAGE: 3/18 ISSUED DATE: 1996. 03. 19 REVISED DATE: 2008. 05. 31 VERSION: 3 GM DAEWOO Auto & Technolog
13、y 4.5. Supplementary symbols These symbols are used to clarify the meaning of dimensions and shall conform to Table 4.2 Division Symbol Read How to use Diameter Radius Diameter of sphere Radius of sphere Side of square Plate thickness Arc length 45 chamfering R SPH SPH R Th C Pi Spherical pi Spheric
14、al RSquare Tie Arc C Placed before dimension value of diameter Placed before dimension value of radius Placed before dimension value of spherical diameter Placed before dimension value of spherical radius Placed before dimension value of a side of a square Placed before dimension value of plate thic
15、kness Placed before dimension value of arc length Placed before dimension value of 45 chamfering Theoretically correct dimensions Reference dimensions ( ) Edge Parenthesis bracket Enclose dimension value of theoretically correct dimensions Enclose dimension value of reference dimensions (including s
16、ymbol) 4.6. Leaders 4.6.1. Leaders are used to direct working method, material, notes, or part numbers in drawings. 4.6.2. A reader shall be drawn at an angle of 60g to the horizontal line as long as possible. The reader directs to the portion to be indicated, and is terminated by an arrowhead or a
17、dot. To the opposite direction, a short straight horizontal line is drawn, above which are entered notes. 4.6.3. In case the notes are long, they are collectively entered at the end of the reader as follows. EDS-A-1103LINEAR AND ANGULAR DIMENSIONS PAGE: 4/18 ISSUED DATE: 1996. 03. 19 REVISED DATE: 2
18、008. 05. 31 VERSION: 3 GM DAEWOO Auto & Technology 5. GENERAL DIMENSIONING METHODS 5.1. Placing of dimension line 5.1.1. The dimension line shall preferably be drawn outside the object using extension lines. In case the extension line may give rise to confusion, however, it may be drawn inside the o
19、bject. 5.1.2. The dimension line shall be drawn in parallel with the direction of measuring the length or angle to be indicated. 5.1.3. The center line, outline, reference line, and their extension lines shall never be used as the dimension line. EDS-A-1103LINEAR AND ANGULAR DIMENSIONS PAGE: 5/18 IS
20、SUED DATE: 1996. 03. 19 REVISED DATE: 2008. 05. 31 VERSION: 3 GM DAEWOO Auto & Technology 5.1.4. The dimension line to enter an angle shall be indicated by an arc drawn between two sides and their extension lines that form an angle with its center at the intersection point. 5.1.5. When it is difficu
21、lt to enter dimensions due to a short dimension line, a leader is used. Where a leader and a dimension line meet is indicated with a dot. 5.1.6. The dimension line shall be separated from the outline by more than 10mm as long as possible, and the space between dimension lines shall be “a“ in the fol
22、lowing table. Drawing size a Letter height A4 A1 8 3.5 A0 or more 10 12 5 EDS-A-1103LINEAR AND ANGULAR DIMENSIONS PAGE: 6/18 ISSUED DATE: 1996. 03. 19 REVISED DATE: 2008. 05. 31 VERSION: 3 GM DAEWOO Auto & Technology 5.2. Placing of extension line 5.2.1. In order to clarify the point or line that in
23、dicates dimensions, a extension line is drawn at an angle of 60 to the dimensions line when required. The direction of the dimension line shall not be changed. 5.2.2. Extension line shall not intersect with each other as long as possible. When intersected inevitably, they shall not be broken, except
24、 for preventing probable misreading. 5.2.3. In case several dimension line are drawn in parallel, the space between them shall be kept regular. 5.3. Entering of dimension values 5.3.1. The dimension value shall be entered above the horizontal dimension line, at the left of the vertical dimension lin
25、e, and properly in between along the inclined dimension line. EDS-A-1103LINEAR AND ANGULAR DIMENSIONS PAGE: 7/18 ISSUED DATE: 1996. 03. 19 REVISED DATE: 2008. 05. 31 VERSION: 3 GM DAEWOO Auto & Technology 5.3.2. The dimension line shall not be separated or overlapped by a line on the drawing. When o
26、verlapped inevitably, the other line is broken where dimension is entered. 5.3.3. The dimension value shall not be entered where dimension lines intersect. 5.3.4. In case it does not matter whether individual dimensional tolerance of several dimensions is accumulated that are entered side by side, t
27、he dimension value is entered side by side. EDS-A-1103LINEAR AND ANGULAR DIMENSIONS PAGE: 8/18 ISSUED DATE: 1996. 03. 19 REVISED DATE: 2008. 05. 31 VERSION: 3 GM DAEWOO Auto & Technology 5.3.5. In case the individual dimensional tolerance of several dimensions which are entered in parallel does not
28、affect the other dimensional tolerance, it is entered in parallel. In this case, the position of the common leader is properly selected considering various conditions including the function and working. 5.3.6. The dimension value shall be so entered as to avoid calculation. It shall be entered from
29、the smaller to the larger when based on the grid line. 6. ENTERING SPECIFIC DIMENSIONS 6.1. Method of indicating diameter 6.1.1. When the cross-section of the object is cylindrical, diameter symbol is entered before the dimension value to indicate its shape in the same size as the dimension value. W
30、hen the object is exactly circular, it may be omitted. EDS-A-1103LINEAR AND ANGULAR DIMENSIONS PAGE: 9/18 ISSUED DATE: 1996. 03. 19 REVISED DATE: 2008. 05. 31 VERSION: 3 GM DAEWOO Auto & Technology 6.1.2. In case several diametric dimensions entered with leaders, which are symmetric with respect to
31、the center line, are placed in a row, dimension lines shall be entered preferably at the same interval along the center line, with the smaller one placed inside and the larger one outside. When the space between dimension lines is very narrow due to inevitable reason, dimensions may be entered zigza
32、g at both sides. 6.1.3. In principle, the radius is entered when the arc is within 180, and the diameter is entered when it is over 180g. In drawings where the symmetric half of the view is omitted, the diameter is entered when it is within 180. 6.1.4. When a leader is used to enter the diameter, th
33、e arrowhead of the leader shall point to the center of the circle. 6.2. Method of dimensioning radius 6.2.1. The radius symbol R of the same size with dimension letters is entered before the dimension value. When the dimension line to indicate the radius is drawn to the center of the arc, this may b
34、e omitted. 6.2.2. The arrowhead designating the radius is drawn on the arc side of the dimension line, and not on the center side. When the space is not available for the arrowhead or dimensions, conform to the following figures. EDS-A-1103LINEAR AND ANGULAR DIMENSIONS PAGE: 10/18 ISSUED DATE: 1996.
35、 03. 19 REVISED DATE: 2008. 05. 31 VERSION: 3 GM DAEWOO Auto & Technology 6.2.3. Use a “+“ symbol or a dot to indicate the center point of an arc. 6.2.4. When an arc has a large radius and its center point is to be indicated but the space is limited, the dimension line of the radius is broken in a Z
36、 shape. Here, the arrowhead of the dimension line shall point to the precise center. 6.2.5. In case of an R of a product which is not viewed R in the drawing, the symbol “TR“ (true radius) is entered before the dimension in the same size as the figure. 6.2.6. In case two or more arcs are entered con
37、tinuously, the larger one is drawn first. In case a specific R is to be drawn first, indicate it with a leader. EDS-A-1103LINEAR AND ANGULAR DIMENSIONS PAGE: 11/18 ISSUED DATE: 1996. 03. 19 REVISED DATE: 2008. 05. 31 VERSION: 3 GM DAEWOO Auto & Technology 6.2.7. For dimensions of the end portion of
38、a round part, only the length, width and the symbol R are indicated. Here, the value of R corresponds to half the width. 6.3. Method of dimensioning spherical diameter and radius The symbol SPH or SPH R of the same size with dimension letters is entered before the dimension value for spherical diame
39、ter and radius respectively. 6.4. Method of dimensioning square In case the object has a square cross-section, its actual is not drawn but instead the symbol of the same size with dimension letters is entered before the dimension value of a side. EDS-A-1103LINEAR AND ANGULAR DIMENSIONS PAGE: 12/18 I
40、SSUED DATE: 1996. 03. 19 REVISED DATE: 2008. 05. 31 VERSION: 3 GM DAEWOO Auto & Technology 6.5. Method of dimensioning thickness In case the dimension of thickness is entered in the main projection drawing, the symbol “Th“ of the same size with dimension letter is entered before the dimension value
41、of thickness, which is placed around or inside the view. 6.6. Method of dimensioning chord and arc 6.6.1. Leaders are drawn perpendicular to the chord and a dimension line parallel with the chord is drawn to indicate chord length. 6.6.2. Leaders are drawn vertically at the arc ends and a dimension l
42、ine parallel with the chord is drawn to indicate arc length. Here, the symbol “ is entered above the dimension value. 6.6.3. In case the angle forming the arc is large or dimensions of arcs are entered continuously, dimensions may be entered above the leaders drawn in the radiant directions from the
43、 arc center. To clarify the length of a specific arc, leaders are drawn from the dimension value to the corresponding arc and an arrowhead is entered to the arc side. EDS-A-1103LINEAR AND ANGULAR DIMENSIONS PAGE: 13/18 ISSUED DATE: 1996. 03. 19 REVISED DATE: 2008. 05. 31 VERSION: 3 GM DAEWOO Auto &
44、Technology 6.7. Method of dimensioning curve 6.7.1. Dimensions of a curve composed of several arcs are generally indicated by the arc radius and center or the position of tangent lines. 6.7.2. While it is possible to read in the actual scale drawing the dimensions of free curves not made up of arcs,
45、 coordinate values of several continual points on the curve is arranged as a table in general when the regulation of major curves is required. 6.8. Method of indicating curve 6.8.1. When it is necessary to specify the working method of holes, such as drilled holes, punched holes and cored holes, the
46、 nominal dimensions and reference dimensions of the tool and the working method are entered in this order in general. The depth of a hole is preceded by the letter “DEPTH“. For penetrated holes, however, the depth is not given. EDS-A-1103LINEAR AND ANGULAR DIMENSIONS PAGE: 14/18 ISSUED DATE: 1996. 0
47、3. 19 REVISED DATE: 2008. 05. 31 VERSION: 3 GM DAEWOO Auto & Technology 6.8.2. For dimensioning of several continuous holes of the same size and same interval, the number of holes and the space are entered. 6.8.3. For screw holes, bolt holes and pin holes, a leader is drawn from the hole to indicate
48、 dimensions of the object. 6.9. Method of dimensioning chamfer General chamfer dimensioning follows the general dimensioning method. In case of a 45g chamfering, dimension is preceded by the symbol C of the same size with dimensioning figures. 6.10. Method of dimensioning theoretically correct dimen
49、sions. The theoretically correct dimensions are indicated by enclosing the dimension value. 6.11. Method of dimensioning slot holes For dimensioning slot holes, a leader is used to enter lengthslot hole width along with letter “SLOT“ of the same size with dimensioning figures. In case of several continuous slot holes of the same size in the same position, the number may be entered. EDS-A-1103LINEAR AND ANGULAR DIMENSIONS PAGE: 15/18 ISSUED DATE: 1996. 03. 19 REVISED DATE: 2008. 05. 31 VERSION: 3 GM DAEWOO Auto & Technology 7. Method of entering
