Manual of Engineering Drawing, Second Edition to British and International Standards

Manual of
Engineering Drawing
Manual of
Engineering Drawing
Second edition
Colin H Simmons
I.Eng, FIED, Mem ASME.
Engineering Standards Consultant
Member of BS. & ISO Committees dealing with
Technical Product Documentation specifications
Formerly Standards Engineer, Lucas CAV.
Dennis E Maguire
CEng. MIMechE, Mem ASME, R.Eng.Des, MIED
Design Consultant
Formerly Senior Lecturer, Mechanical and
Production Engineering Department, Southall College
of Technology
City & Guilds International Chief Examiner in
Engineering Drawing
Elsevier Newnes
Linacre House, Jordan Hill, Oxford OX2 8DP
200 Wheeler Road, Burlington MA 01803
First published by Arnold 1995
Reprinted by Butterworth-Heinemann 2001, 2002
Second edition 2004
Copyright © Colin H. Simmons and Denis E. Maguire, 2004. All rights reserved
The right of Colin H. Simmons and Dennis E. Maguire to be identified as the authors
of this work has been asserted in accordance with the Copyright, Designs and
Patents Act 1988
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A catalogue record for this book is available from the British Library
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A catalog record for this book is available from the Library of Congress
ISBN 0 7506 5120 2
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Contents
Preface
vii
Acknowledgements ix
1 Drawing office management and organization 1
2 Product development and computer aided design 7
3 CAD organization and applications 13
4 Principles of first and third angle orthographic projection 33
5 Linework and lettering 45
6 Three dimensional illustrations using isometric and oblique projection 50
7 Drawing layouts and simplified methods 54
8 Sections and sectional views 64
9 Geometrical constructions and tangency 68
10 Loci applications 73
11 True lengths and auxiliary views 82
12 Conic sections and interpenetration of solids 87
13 Development of patterns from sheet materials 93
14 Dimensioning principles 100
15 Screw threads and conventional representations 114
16 Nuts, bolts, screws and washers 120
17 Keys and keyways 134
18 Worked examples in machine drawing 137
19 Limits and fits 153
20 Geometrical tolerancing and datums 160
21 Application of geometrical tolerances 168
22 Maximum material and least material principles 179
23 Positional tolerancing 186
24 Cams and gears 190
25 Springs 202
26 Welding and welding symbols 210
27 Engineering diagrams 214
28 Bearings and applied technology 249
29 Engineering adhesives 264
30 Related standards 272
31 Production drawings 282
32 Drawing solutions 291
Index 297
This latest edition of A Manual of Engineering Drawing
has been revised to include changes resulting from the
introduction of BS 8888. British Standard 308 was
introduced in 1927 and acknowledged by Draughtsmen
as THE reference Standard for Engineering Drawing.
The British Standards Institution has constantly kept
this Standard under review and taken account of
technical developments and advances. Since 1927, major
revisions were introduced in 1943, 1953, 1964 and
1972 when the contents of BS 308 Engineering
Drawing Practice was divided into three separate
sections.
Part 1: General principles.
Part 2: Dimensioning and tolerancing of size.
Part 3: Geometrical tolerancing.
In 1985, the fifth revision was metricated.
During the period 1985--2000 major discussions were
undertaken in co-operation with International Standards
Organizations.
The general trend in Engineering Design had been
that the designer who was responsible for the conception
and design of a particular product generally specified
other aspects of the manufacturing process.
Gradually however, developments from increased
computing power in all aspects of production have
resulted in progressive advances in manufacturing
techniques, metrology, and quality assurance. The
impact of these additional requirements on the Total
Design Cycle resulted in the withdrawal of BS 308 in
2000. Its replacement BS 8888 is a far more
comprehensive Standard.
The full title of BS 8888 reflects this line of thought.
BS 8888. Technical product documentation (TPD).
Specification for defining, specifying and graphically
representing products.
It must be appreciated and emphasized that the
change from BS 308 to BS 8888 did not involve
abandoning the principles of Engineering Drawing in
BS 308. The new Standard gives the Designer a vastly
increased number of tools at his disposal.
It is important to stress that British and ISO drawing
standards are not produced for any particular draughting
method. No matter how a drawing is produced, either
on an inexpensive drawing board or the latest CAD
equipment, the drawing must conform to the same
standards and be incapable of misinterpretation.
The text which follows covers the basic aspects of
engineering drawing practice required by college and
university students, and also professional drawing office
personnel. Applications show how regularly used
standards should be applied and interpreted.
Geometrical constructions are a necessary part of
engineering design and analysis and examples of two-
and three-dimensional geometry are provided. Practice
is invaluable, not only as a means of understanding
principles, but in developing the ability to visualize
shape and form in three dimensions with a high degree
of fluency. It is sometimes forgotten that not only does
a draughtsman produce original drawings but is also
required to read and absorb the content of drawings he
receives without ambiguity.
The section on engineering diagrams is included to
stimulate and broaden technological interest, further
study, and be of value to students engaged on project
work. Readers are invited to redraw a selection of the
examples given for experience, also to appreciate the
necessity for the insertion and meaning of every line.
Extra examples with solutions are available in
Engineering Drawing From First Principles using
AutoCAD, also published by Butterworth-Heinemann.
It is a pleasure to find an increasing number of
young ladies joining the staff in drawing offices where
they can make an effective and balanced contribution
to design decisions. Please accept our apologies for
continuing to use the term 'draughtsmen', which is
the generally understood collective noun for drawing
office personnel, but implies equality in status.
In conclusion, may we wish all readers every success
in their studies and careers. We hope they will obtain
much satisfaction from employment in the absorbing
activities related to creative design and considerable
pleasure from the construction and presentation of
accurately defined engineering drawings.
Preface
Acknowledgements
The authors express their special thanks to the British
Standards Institution Chiswick High Road, London,
W4 4AL for kind permission to reprint extracts from
their publications.
We are also grateful to the International Organization
for Standardization, Geneve 20, Switzerland, for
granting us permission to use extracts from their
publications.
We very much appreciate the encouragement and
friendly assistance given to us by:
H C Calton, Ford Motor Company Ltd
Geoff Croysdale, SKF (UK) Ltd
Susan Goddard, KGB Micros Ltd
Emma McCarthy, Excitech Computers Ltd
John Hyde, Norgren Martonair Ltd
Bob Orme, Loctite Holdings Ltd
Tony Warren, Staefa Control System Ltd
Autodesk Ltd
Mechsoft
Barber and Colman Ltd
Bauer Springs Ltd
Delphi Diesel Systems
GKN Screws and Fasteners Ltd
Glacier Vandervell Ltd
Lucas Diesel Systems
Lucas Electronic Unit Injector Systems
F S Ratcliffe Ltd
Salterfix Ltd
Matthew Deans and his staff at Elsevier: Nishma, Doris,
Rachel and Renata.
Brian and Ray for sheet metal and machine shop
examples, models, computer advice and technical
support.
Our final thanks go to our patient and understanding
wives, Audrey and Beryl, for all their typing and clerical
assistance since we started work in 1973 on the first
edition of Manual of Engineering Drawing.
Every article used in our day-to-day lives will probably
have been produced as a result of solutions to a sequence
of operations and considerations, namely:
1 Conception
2 Design and analysis
3 Manufacture
4 Verification
5 Disposal.
The initial stage will commence when an original
marketable idea is seen to have a possible course of
development. The concept will probably be viewed
from an artistic and a technological perspective.
The appearance and visual aspects of a product are
very important in creating an acceptable good first
impression.
The technologist faces the problem of producing
a sound, practical, safe design, which complies with
the initial specification and can be produced at an
economical cost.
During every stage of development there are many
progress records to be maintained and kept up to date
so that reference to the complete history is available to
responsible employees.
For many years various types of drawings, sketches
and paintings have been used to convey ideas and
information. A good recognizable picture will often
remove ambiguity when discussing a project and assist
in overcoming a possible language barrier.
British Standards are listed in the British Standards
Catalogue and the earliest relevant Engineering
Standards date back to 1903. Standards were developed
to establish suitable dimensions for a range of sizes of
metal bars, sheets, nuts, bolts, flanges, etc. following
the Industrial Revolution and used by the Engineering
Industry. The first British Standard for Engineering
Drawing Office Practice published in September 1927
only contained 14 clauses as follows:
1 Sizes of drawings and tracings, and widths of
tracing cloth and paper
2 Position of drawing number, date and name
3 Indication of scale
4 Method of projection
5 Types of line and writing
6 Colour of lines
7 Dimension figures
8 Relative importance of dimensions
9 Indication of materials on drawings
10 Various degrees of finish
11 Screw threads
12 Flats and squares
13 Tapers
14 Abbreviations for drawings.
There were also five figures illustrating:
1 Method of projection
2 Types of line
3 Views and sections
4 Screw threads
5 Tapers.
First angle projection was used for the illustrations
and the publication was printed on A5 sheets of paper.
During the early days of the industrial revolution
manufacturers simply compared and copied component
dimensions to match those used on the prototype.
However, with the introduction of quantity production
where components were required to be made at different
factory sites, measurement by more precise means was
essential. Individual manufacturers developed their own
standard methods. Clearly, for the benefit of industry
in general a National Standard was vital. Later the
more comprehensive British Standard of Limits and
Fits was introduced. There are two clear aspects, which
are necessary to be considered in the specification of
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