BS8888 Drafting

--L---.

Engineering Part 2: A guide for higher education to as 8888:2000, Technical product documentation

,:,

~.~. *~~-

"'M\ UI&..

Contents Contents Foreword Scope Listoffigures,tablesanddrawings... 1 Layout of drawings 2Scales 3Projection 4Linesandarrows 5Letteringandnumerals 6Views 7 Sections and sectional views 8Symbolsandabbreviations 9Itemreferences 10 Representation of features 11 Representation of components 12Dimensioning 13Dimensioningfromacommonfeature

Page 1 2 ...,

,.

""""

..4 9 13 14 17 22 24 28 35 37 39 44 49 58

14 Tolerancing

',

15Methodsofindicatingsurfacetexture.., 16Diagrams 17 Microcopying and storage Annex A (informative) Correspondence between BS 308-1 and BS 8888. . . . . . . . . . . . . . . . Annex B (informative) Examples of mechanical engineering drawings. . . . . . . . . . . . . . . . . Annex C (informative) Approaches to 3-D modelling.

71 101 109 112 116 119

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121

Annex D (informative) A model of geometric product specification (GPS) and verification. . 122 AnnexE(informative)BS8888kits 128 Annex F (informative) Examples of the application of different types of line. . . . . . . . . . . . 130 Bibliography 139 Index 142

)

I 3

1-

-.....-.

1 Layout of drawings 1.1 General This clause gives guidance on best-practice in the layout of pre-printed technical drawings, including those produced by computers. 1.2 Drawing sheets The "A" series of drawing sheets, shown in Figure 1, is normally used. The drawing area and title block should be within a frame border. In general, material within the frame border forms part of any contract requirements.

= 210 mm = 297 rom = 420 mm

x 297 mm x 420 mm x 594 mm = 594 rom x 841 rom AO = 841 mm x 1189 rom The sides of all sheets are in the ratio 1: ff A4

A3 A2 Al

AO is normally one square metre in area and forms the basis of the series.

Figure 1 - Relationship of the "A" sizes 1.3 Title block The title block for paper sizes AOto A3 should be situated in the bottom of the sheet and extend to the lower right-hand comer of the frame. Only sheets positioned horizontally are permitted for these formats. For A4 size paper, the title block is situated in the shorter (lower) part of the drawing space. Only sheets positioned vertically are allowed for this format. The direction of reading of the drawings is equal to that of the title block. Drawings should include the following basic information in the title blocks: - name; - date; - projection symbol (see Clause 3); - original scale (see Clause 2); - title; - drawing number.

i

~_.-

9

1.4 Borders and frames Borders enclosed by the edges of the trimmed sheet and the frame limiting the drawing space should be provided with all sizes. The border should be 20 mm wide on the left edge, including the width of the frame. It can be used as a filing margin. All other borders are 10 mm wide (See Figure 2). 2

4

Dimensions in millimetres

5

3

20

Key 1 Trimming mark 2 Trimmed format 3 Grid reference

4 Frame of drawing space 5 Drawing space 6 Untrimmed format Figure 2

-

Borders

1.5 Drawing formats Drawing sheets may be produced in two formats. Portrait format is intended to be viewed with the longest side of the sheet vertical, see Figure 3a). Landscape format is intended to be viewed with the longest side of the sheet horizontal, see Figure 3b), Figure 3c) and Figure 3d).

~

-!f}

b)

I

£I

c)

a) Detail (single part) drawings

10 :

'

-r--'--

----.--

I

I

/0. TAPER PIN

1

3 PIN 2 PUllEY

1 1

1 ITEM

Figure 3

BRACJ

S" '"S

f')

= f!)

I ('j = =

5r IJQ N

= ~

'"S

10

'~

=t=

\

DRAWING

No:

2

CONNEC TOR

A-A

TITLE:

~

::f:

.4!ti.,

~~ {i I

29.09.01

CHECKED BY: G.E. TORRENS DATE: 08.10.01

DATE:

DRAWN BY: G.LWlWAMS

turned Rz 3,5

2'

UNLESS

OTHERWISE STATED

ANGULAR;/;

UN EAR ::t: 0.2

GENERAL TOLERANCES:

2 BOTH SIDES

18 10

DIMENSIONS

'~

IN: mm

I

I .q

g

co EI

DETAIl.. X SCALE 6: 1

,--------

~---~-,'

DO NOT SCALE IN ACCORDANCE WITHBS 8888 ANISH: MA1ERIAL: / STEEL TO 8 S 970 'V ALL OVER REVISION: 02.11.01 PR..ECTlON: FIRST ANGLE ORIGINAL SCALE: 1: 1

166

ii

coco

~~