1、BRITISH STANDARD BS 5536:1988 Recommendations for Preparation of technical drawings for microfilming UDC 778.14:744.4BS5536:1988 This British Standard, having been prepared under the directionof the General Mechanical Engineering Standards Committee, was published under the authority ofthe Board of
2、BSI and comes intoeffect on 31 August 1988 BSI 03-1999 First published January 1978 First revision August 1988 The following BSI references relate to the work on this standard: Committee reference GME/4 Draft for comment 87/71846 DC ISBN 0 580 16778 X Committees responsible for this British Standard
3、 The preparation of this British Standard was entrusted by the General Mechanical Engineering Standards Committee (GME/-) to Technical Committee GME/4, upon which the following bodies were represented: Amalgamated Union of Engineering Workers (Technical and Supervisory Section) British Paper and Boa
4、rd Industry Federation British Railways Board British Standards Society Drawing Office Material Manufacturers and Dealers Association Electricity Supply Industry in England and Wales Electronic Engineering Association Engineering Equipment and Materials Users Association Gauge and Tool Makers Associ
5、ation Institution of Chemical Engineers Institution of Electrical Engineers Institution of Electronic and Radio Engineers Institution of Engineering Designers Institution of Mechanical Engineers Institution of Production Engineers Ministry of Defence Society of British Aerospace Companies Limited Te
6、lecommunication Engineering and Manufacturing Association United Kingdom Atomic Energy Authority The following body was also represented in the drafting of the standard, through subcommittees and panels: Post Office Amendments issued since publication Amd. No. Date of issue CommentsBS5536:1988 BSI 0
7、3-1999 i Contents Page Committees responsible Inside front cover Foreword ii 1 Scope 1 2 Drawing sheets 1 3 Materials 1 4 Presentation 1 5 Lines 1 6 Form, size and spacing of characters 2 7 Scale on drawings 2 8 Care of drawings 3 9 Original drawings 3 Figure 1 Example of thin material in section 2
8、Figure 2 Examples of letters and numerals 3 Figure 3 Example of a drawing suitable for microfilming 4 Table 1 Drawing sheet sizes and frame sizes (trimmed) 1 Table 2 Minimum character height for capital letters and numerals 2 Publications referred to Inside back coverBS5536:1988 ii BSI 03-1999 Forew
9、ord This revision of BS 5536 has been prepared under the direction of the General Mechanical Engineering Standards Committee and supersedes BS 5536:1978 which was published as a specification and is now withdrawn. It is intended for all technical drawing that may be microfilmed and is complementary
10、to BS 308, BS 1192 and BS 5070 which are also recommendations. It is related to ISO 6428, published by the International Organization for Standardization (ISO). Whereas BS 5536:1978 was presented as a specification, having regard to progress in standards making policy in the interim, it became appar
11、ent that this subject was no longer suitable as a specification and this revision is presented in the form of recommendations. Technical drawings complying with the recommendations of this standard and BS 308, BS 1192 or BS 5070 should be capable of being recorded on, and subsequently reproduced fro
12、m, microfilm without significant loss of quality at camera reduction ratios up to 1 : 30. The draughting requirements for microfilming are important and therefore all drawings and diagrams, whether produced manually or by machine and which comply with the recommendations of this standard, will enabl
13、e any recipient of the microfilm, whether in the United Kingdom or overseas, to obtain a satisfactory reproduction. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a B
14、ritish Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, pages 1 to 4, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have had amendmen
15、ts incorporated. This will be indicated in the amendment table on theinside front cover.BS5536:1988 BSI 03-1999 1 1 Scope This British Standard gives recommendations for the preparation and care of all types of technical drawings intended for microfilming in accordance with BS 4210. NOTEThe titles o
16、f the publications referred to in this standard are listed on the inside back cover. 2 Drawing sheets 2.1 Sizes Drawing sheets should comply with the sizes given in BS 3429 and Table 1. Drawing sheets larger than A0 size should be avoided owing to the limitations of microfilming equipment normally a
17、vailable (see 2.2). 2.2 Drawing frame and centring marks The most critical dimensions are those of the drawing frame which relate to the nominal sheet sizes as given in Table 1. A centring mark in the form of a line should be shown at the centre of each of the four sides of the drawing frame given i
18、n Table 1 and to be within a tolerance of 1mm of the true position. If the use of a sheet larger than A0 is essential, then additional marks will be needed on the drawing to allow for filming of the drawing on more than one microfilm frame. In this instance the centring marks should be placed to coi
19、ncide with the intended centre position of each individual microfilm frame and to permit an overlap of approximately100mm between frames. In this case the position of the centring marks will not need to be as critical as for the drawing frame sizes given in Table 1. Table 1 Drawing sheet sizes and f
20、rame sizes (trimmed) 3 Materials 3.1 Drawing sheets should have a matt surface so as to minimize reflectance. 3.2 On translucent material all drawing information including the pre-printing should preferably appear on the front of the drawing sheet. Some loss of microfilm quality may result if pre-pr
21、inting and other information is filmed through the material thickness. 3.3 Pencils and inks that give lines with matt surfaces should be used. In this respect polymer type pencil leads are superior on draughting film to graphite (see also 8.4). 3.4 The drawing board facing or an intermediate backing
22、 sheet, should be chosen so as to minimize indentation of the drawing sheet as indentations can detract from the clarity of reproduction through the effects of reflected and refracted light and can cause ghost images to appear when microfilming. NOTEAdhesive overlays may deteriorate with age and acc
23、umulate dust and such defects may then adversely affect the quality of the microfilm. 4 Presentation Views should be spaced so that dimensions and notes can be clearly presented. Areas of fine detail should be shown suitably enlarged (see Figure 3). 5 Lines 5.1 All lines, including those added in an
24、y revision of the drawing, should be consistently black and dense. The lines on any one drawing sheet should preferably be entirely in pencil or entirely in ink. If pencil and ink are used on the same drawing, every effort should be made to ensure that uniform density and reflectance are maintained.
25、 5.2 Each type of line should be of consistent thickness. The minimum thickness of line for satisfactory microfilming is0.25mm. 5.3 To allow for limitations on print-out and viewing of reduced microfilm copies, adjacent lines should be spaced not less than 1 mm apart. In some cases this may result i
26、n certain features having to be exaggerated locally on the drawing. Thin material in section may be shown as single solid lines in preference to showing the material thickness out of scale. When adjacent parts are thus shown, a space of not less than1mm should be left between them for clarity (see F
27、igure 1). Black areas wider than3mm should be avoided due to the limitations of some print-out processes. Designation Size Minimum border width from drawing frame to edge of sheet mm mm A0 A1 A2 A3 A4 841 1189 594 841 420 594 297 420 210 297 20 20 10 10 10BS5536:1988 2 BSI 03-1999 6 Form, size and s
28、pacing of characters 6.1 It is important that characters should be uniform and equally capable of being produced by hand, stencil, machine or other means. The characters on the drawing should remain legible not only in full size copy but in the form of reduced copy or as an image on a microfilm view
29、ing screen. Clarity, style, size and spacing are important, particularly for numerals, as unlike letters they rarely fall into identifiable patterns and have to be read individually. Characters should be open form and devoid of embellishments. All strokes should be black and of consistent density co
30、mpatible with the line work. Care should be taken that sufficient space exists between characters and parts of characters to ensure that “filling in” will not take place during reproduction. 6.2 No particular style of lettering is recommended; the aim should be to produce legible and unambiguous cha
31、racters. Where confusion may arise between a capital letter I and the numeral 1 it is recommended that a top serif be added to the numeral 1. Particular care should also be taken to ensure that such characters as B and 8, Z and 2 and S and 5, will not be confused. The smaller angles contained in slo
32、ping letters may prove slightly inferior in microfilm reproduction. Capital letters are preferred to lower case as they are less congested and are less likely to be misread when reduced in size. Lower case letters should be restricted to instances where they form part of a standard symbol, code or a
33、bbreviation. Table 2 gives minimum recommended heights for capital letters. However, when lower case letters are used they should be proportioned so that the body height is approximately0.6times the capital letter height. The numerator and denominator of a fraction should each be of the size recomme
34、nded for letters and numerals given in Table 2. NOTEThe examples in Figure 2, which have been produced by the use of stencils, are provided as a guide only. Table 2 Minimum character height for capital letters and numerals 6.3 The stroke thickness of the character should be approximately 0.1times th
35、e height and the clear space between characters and parts of characters should be approximately0.7mm for capitals and numerals of 2.5mm height, other sizes being in proportion. The space between lines of lettering should be not less than half the character height, but for titles closer spacing may s
36、ometimes be unavoidable. 6.4 To facilitate reading from a microfilm viewing screen, all notes should be placed so that they can be read from the same direction as the format of the drawing. Where a long vertical object is to be drawn horizontally on a landscape drawing sheet, the base of the object
37、should be drawn on the right-hand side and the width dimensions should be readable from the right-hand side of the drawing. 6.5 When mechanical means for lettering are used (such as typewriters, plotters, etc.), the density should, as far as possible, be the same as that of the other lines on the do
38、cument. The type of lettering and its dimensions should be similar to those shown in Figure 2. NOTE 1Clarity of character image can be achieved by using only capital letters and using one-time printing ribbons. NOTE 2Typing on polyester material requires a special total transfer ribbon which has low
39、 reflectance and high density. 7 Scale on drawings Because the size of the copy printed from microfilm will almost certainly be different from the size of the original, it is essential that reference to the scale used should be stated on the drawing, e.g. “Original scale1 : 5”. The original scale sh
40、ould be indicated by means of a relevant numbered scale bar. If desired, a warning against scaling the drawing may be given. Figure 1 Example of thin material in section Application Drawing sheet size Minimum character height mm Drawing number and title A0, A1, A2 and A3 7 A4 5 Dimensions and all ot
41、her characters A0 3.5 A1, A2, A3 and A4 2.5BS5536:1988 BSI 03-1999 3 8 Care of drawings 8.1 For storage, drawings should preferably be laid flat or be suspended. They should not be folded, but drawings on draughting film may be rolled and placed in a protective tube, the diameter of which should be
42、chosen to suit the material composition. For transit, drawings should be wrapped (drawing side inwards) and retained around a tube of not less than75mm diameter (this value may be reduced for draughting film) then placed in a protective outer tube. 8.2 Edge binding of drawings intended for microfilm
43、ing is not recommended. Where edge binding of drawings is undertaken, the shrinkage properties of the tape used should be compatible with those of the drawing sheet material. 8.3 When erasures are necessary, care should be taken to ensure that any impairment of the drawing surface is minimal. 8.4 Wh
44、ere, contrary to the recommendations given in 3.3, drawings are prepared with graphite pencils, consideration should be given to the use of a non-toxic fixative to prevent smudging. NOTEThe use of fixatives is likely to complicate satisfactory erasure. 9 Original drawings The best microfilming resul
45、ts will be obtained using the original ink (or pencil) drawing. When a design change is made or a different use is envisaged that requires a new drawing to be made, consideration should be given to replacing the original drawing with a reproducible and then modifying the original for the new purpose
46、. This procedure will minimize the microfilming of reproduced drawings and increase the use of the high quality, high cost original. NOTEThese examples, which have been produced by the use of stencils, are provided as a guide only. Figure 2 Examples of letters and numeralsBS5536:1988 4 BSI 03-1999 N
47、OTEThe circled numbers refer to clauses in the text. Figure 3 Example of a drawing suitable for microfilming BS5536:1988 BSI 03-1999 Publications referred to BS 308, Engineering drawing practice 1) . BS 1192, Construction drawing practice 1) . BS 3429, Specification for sizes of drawing sheets. BS 4
48、210, Specification for 35 mm microcopying of technical drawings. BS 5070, Engineering diagram drawing practice 1) . ISO 6428, Technical drawings Requirements for microcopying 1) . 1) Referred to in the foreword only.BSI 389 Chiswick High Road London W4 4AL | | | | | | | | | | | | | | | | | | | | | |
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