ISO-128-20-1996.pdf

INTERNATIONAL STANDARD IS0 128-20 First edition 1996-l l-l 5 Technical drawings - General principles of presentation - Part 20: Basic conventions for lines Dessins techniques - Principes g figure 2 b): a continuous and a dashed spaced line. a) b) Figure 2 b) Arranged next to each other. See figure3 for an example (two continuous lines either side of two dashed spaced lines). Figure 3 3.3.3 Arrangement of two continuous lines parallel to each other with regularly recurring connecting elements between them See figure4a) and b) for examples figure 4a): blackened circular elements; figure 4b): blackened trapezoidal elements. b) Figure 4 0 IS0 IS0 128-20:1996(E) 3.3.4 Arrangement of regularly recurring geometric pictorial elements in association with continuous lines a) Without interruption of a continuous line. See figure 5 for examples. I I I I I I I L L L L L L A A A A A A A I I I I I I I Figure 5 b) With interruption of a continuous line. See figure 6 for examples. Figure 6 4 Line dimensions 4.1 Line width The width, d, of all types of lines shall be one of the following depending on the type and size of the drawing. This series is based on a common ratio 1: J- 2 (z 1:1,4): 0,13 mm; 0,18 mm; 0,25 mm; 0,35 mm; 0,5 mm; 0,7 mm; 1 mm; 1,4 mm; 2 mm The widths of extra wide, wide and narrow lines are in the ratio 4:2:1. The line width of any one line shall be constant throughout the whole line. 4.2 Deviation in line width Line widths may deviate from those specified in 4.1 providing that it is possible to differentiate unambiguously between two adjacent lines with different widths. If drawing equipment which produces constant line width is used, the deviation in line width between two such lines shall not be greater than + 0,ld. 5 -,-,- IS0 128-20:1996(E) 4.3 Configuration of lines For the preparation of drawings by hand the lengths of line elements should conform to those of table3. Table 3 Line element Line type No. Length Dots 04 to 07 0,5d and 10to15 Gaps 02 and 04 to 15 3d Short dashes Dashes 08 and 09 02, 03 and 10 to 15 6d 12d Long dashes 04 to 06, 08 and 09 24d Spaces 03 18d NOTE - The lengths shown in this table are valid for line elements with semi- circular and squared ends. In the case of line elements with semicircular ends, the length of the line element corresponds to the distance covered by a technical pen (with a tubular tip and using India ink) from the origin up to the end of the line element. The total length of such a line element is the sum of the length shown in table3 plus d. Formulae for the calculation of some of the basic types of line and line elements are given in IS0 128-21. The formulae are intended to facilitate the preparation of drawings using computer-aided design (CAD) systems. 5 Draughting of lines 5.1 Spacing The minimum space between parallel lines should not be less than 0,7 mm, unless rules to the contrary are stated in other International Standards. NOTE 4 In certain cases when computer-aided drawing techniques are used, the spacing of lines on the drawing does not represent the actual spacing, e.g. for the representation of screw threads. This fact has to be considered when data sets are established, e.g. for the operation of machine tools. 6 -,-,- 5.2 Junctions 5.2.1 Types The basic types of lines, Nos. 02 to 06 and Nos. 08 to 15 should preferably meet at a dash; see figures 7 to 12. I I I /J + / - - - - - - j- / I I I Figure 7 Figure 8 l I- I -I-, Figure 9 Figure 10 Figure 11 Figure 12 -,-,- IS0 128-20:1996(E) Lines of basic type No. 07 should preferably meet at a dot, see figure 13. . . . . Figure 13 5.2.2 Representation The requirement of 5.2.1 shall be fulfilled by starting the lines at the junction (see figure 14) or by using a complete, or partial, cross formed by dashes (see figures 15 and 16). .-.- -.-.-.- / / -. Y f Figure 14 Figure 16 -,-,- 0 IS0 1s0 128-20:1996(E) 5.3 Location of a second line Two different ways of draughting two parallel lines are shown in figure 17 a) and b). The preferred version is shown in figure 17a) (the second line is drawn below or to the right of the first line). Ir - -1 a) b) Figure 17 6 Colours Lines shall be drawn in black or white depending on the colour of the background. Other standardized colours may also be used for drawing standardized lines. In this case, the meaning of the colours shall be explained. 7 Designation The designation of the basic types of lines shall comprise the following elements in the order given: a) I Line”; b) reference to this part of IS0 128; c) the number of the basic type in accordance with table 1; d) the line width in accordance with 4.1; e) the colour (if applicable). EXAMPLES Designation of a line of type No. 03 (031, line width 0.25 mm (0,251: Line IS0 128-20 - 03 x 0,25 Designation of a line of type No, 05 (051, line width 0.13 mm (0,13) and white in colour: Line IS0 128-20 - 05 x 0,13 / white -,-,- IS0 128-20:1996(E) 0 IS0 Annex A (informative) Bibliography I IS0 128-21:19961, Technical drawings - Gen- eral principles of presentation - Part 27: Prep- aration of lines by CAD systems. 2 IS0 1219-l:1991, Nuid power systems and components - Graphic symbols and circuit dia- grams - Part I: Graphic symbols. 3 IS0 351 l-l :1977, Process measurement control functions and instrumentation - Symbolic rep- resentation - Part 1: Basic requirements. 4 IS0 3511-2:1984, Process measurement control functions and instrumentation - Symbolic rep- resentation - Part 2: Extension of basic re- quiremen ts. S IS0 351 l-3:1 984, Process measurement control functions and instrumentation - Symbolic rep- resentation - Part 3: Detailed symbols for in- s trumen t interconnection diagrams. 6 IS0 351 l-4:1 985, industrial process measure- ment control functions and instrumentation - Symbolic representation - Part 4: Basic sym- bols for process computer, interface, and shared display/control functions. 7 IS0 5455:1979, Technical drawings - Scales. 8 IS0 6428:1982, Technical drawings - Require- ments for microcopying. 9 IS0 10628-1:1996lJ, Flow diagrams for process plants - Part 1: General rules. 1) To be published. 10 -,-,- IS0 l284!0:1996(E) ICS 01.100.01 Descriptors: drawings, technical drawings, lines, presentation. dimensions, designation, generalities Price based on 10 pages -,-,-