Manual of Engineering Drawing Technical Product Specification and Documentation to British and International Standards Fourth Edition Colin H. Simmons I.Eng, FIED International Engineering StandardsConsultant Member ofBS and ISO Committeesdealing with Technical Product specificationsandDocumentation FormerlyGlobalStandards Engineer,LucasCAV Neil Phelps IEng MIED, MIET Practising MechanicalDesign Manager Member ofBSI and ISO Committeesdealing with TechnicalProduct Documentation specifications and Realization Chairman BSI CommitteeCovering Digital Product Specification The Late Dennis E. Maguire CEng, MIMechE, Mem ASME, REng.Des,MIED Design Consultant FormerlySenior Lecturer, Mechanical and Production Engineering Department, Southall College ofTechnology Cityand Guilds International Chief Examiner in Engineering Drawing AMSTERDAMlBOSTONlHEIDELBERGlLONDONlNEWYORKlOXFORDlPARIS SANDIEGOlSANFRANCISCOlSINGAPORElSYDNEYlTOKYO Butterworth-HeinemannisanimprintofElsevier Butterworth-Heinemann isan imprint of Elsevier TheBoulevard, Langford Lane, Kidlington, Oxford, OX51GB, UK 225Wyman Street, Waltham, 02451, USA First editionby Arnold 1995 Reprinted by Butterworth Heinemann 2001,2002 Second edition 2004 Reprinted 2004, 2005, 2006 Third edition 2009 Fourth edition 2012 Copyright (cid:2) 2012Elsevier Ltd. All rights reserved. Nopart ofthis publicationmay bereproduced or transmittedin anyform orby anymeans, electronicor mechanical, including photocopying, recording,or anyinformation storage and retrieval system,withoutpermission inwriting from the publisher. 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Tothefullestextentofthelaw,neitherthePublishernortheauthors,contributors,oreditors,assumeanyliabilityforany injury and/ordamage topersonsor propertyas amatterof products liability, negligence orotherwise, orfrom anyuse operation ofanymethods, products, instructions, orideascontained inthe materialherein. British Library Cataloguingin Publication Data Acataloguerecordfor this book isavailable from the British Library LibraryofCongressCataloging-in-Publication Data Acatalog recordfor this book isavailablefrom the Library ofCongress ISBN: 978-0-08-096652-6 Forinformation onall Elsevier publications visit ourwebsite at www.elsevierdirect.com Printed and bound inGreat Britain 12 11 10 9 87 6 5 43 2 1 Preface The request to prepare a fourth edition of Manual of giving us the opportunity to enhance and enlarge the EngineeringDrawingafterarelativelyshortperiodof chapter ‘Geometrical Tolerancing and Datums’. The time since the successful launch of the third edition basic tenets are illustrated to show how datums and was welcomed by Neil and myself, as it gave us an datum systems are used as the basis for establishing opportunity to update, revise and elaborate some of geometric relationships of related features. the chapters in relation to the latest developments Thechapterillustratingthedifferencesbetweenthe created in the ever-changing world of engineering American ASME Y 14.5M Geometric Dimensioning technology: particularly those made in the fields of and Tolerancing (GD&T) and the relative ISO / BS technical product documentation and specification, 8888 Geometric Dimensioning and Tolerancing Stan- created by the ISO committees TC10 Technical dards has been elaborated and pictorially enhanced, ProductDocumentationandTC213TechnicalProduct with the aim of improved user friendliness. Specification e the precepts of which are faithfully AllchapterswhosecontentsarerelatedtoISO/BS adhered to in the British Standard BS 8888 published 8888havebeenupdated,toreflectcurrentpracticesin in December 2011, as is this fourth edition. line with the latest ISO developments. It also gave us the opportunity to further enhance The text that follows covers the basic aspects of themanual’scontentbyintroducingthreenewchapters engineering drawing practice required by college and on topical subject matters, namely: university students, and also professional design and ‘Design for Manufacture to End of Life’, which is drawingofficepersonnel.Applicationsshowhowregu- intended to give the reader an insight into this rapidly larlyusedstandardsshouldbeappliedandinterpreted. developing field of engineering by explaining the Geometrical constructions are a necessary part of relationshipbetweendesign,theproductlifecycleand engineeringdesignandanalysis,andexamplesoftwo- environmental considerations. This being a pertinent, andthree-dimensionalgeometryareprovided.Practice relatively new topic e driven by environmental is invaluable, not only as a means of understanding requirements and potential cost savings e it is being principles, but in developing the ability to visualize adoptedbytheindustryandbecomingstandardizedin shapeandforminthreedimensionswithahighdegree BS 8887. of fluency. It is sometimes forgotten that not only do ‘Surface Finish and Corrosion of Metals’, which designers or draughtsmen produce original drawings, has been added to complement the existing chapter but they are also required to read and absorb the ‘Surface Texture’. Although not exhaustive, it is content of drawings they receive, without ambiguity. intended to provide a basic understanding of the Thesectiononengineeringdiagramsisincludedto subject matter and provide a reference to associated stimulate and broaden technological interest and Standards. It should also eliminate any possible further study, and be of value to students engaged on confusion, which unfortunately does widely exist, in projectwork.Readersareinvitedtoredrawaselection the comprehension of these two terms surface texture of the examples given for experience, and also to and surface finish. appreciate the necessity for the insertion and meaning ‘IntellectualProperty(IP)andEngineeringDesign’, of every line. whichprovidesanoverviewoftheconnectionbetween Please accept our apologies for continuing to use the main types of intellectual property (IP) and engi- the term draughtsmen, which is the generally under- neering design, together with its associated documen- stoodcollectivenounfordrawingofficepersonnel,but tation. The benefits and the unexpected pitfalls of implies equality in status. costlylegislationinfringement,intowhichthedesigner In conclusion, may we wish all readers every may inadvertently stray, are fully explained. successintheirstudiesandcareers.Wehopetheywill Since the last edition the long awaited ISO Datum obtain much satisfaction from employment in the Standard ISO 5459 has now been published, thus absorbing activities related to creative design and vii viii Preface considerable pleasure from the construction and literarypublications,forhiscontinueddedicatedinput, presentation of accurately defined engineering draw- and acumen, in making this fourth edition possible, ings incapable of misinterpretation. and I hope that this edition of Manual of Engineering Finally, I wish to record my sincere thanks to my Drawingwillenjoycontinuedsuccessinthefuture,as valued friend and co-author, Neil Phelps, a treasured it has proven to have done over the past decades. colleague, of many years standing in the field of National and International Standardization, and past Colin Simmons Contents Preface vii 20. Worked Examples in Machine Acknowledgements ix Drawing 159 21. Limits and Fits 175 22. Geometrical Tolerancing and 1. Drawing Office Management Datums 183 and Organization 1 23. Application of Geometrical 2. Product Development and Tolerances 195 Computer Aided Design 9 24. Maximum Material and Least 3. Design for Manufacture to Material Principles 211 End of Life 15 25. Positional Tolerancing 219 4. Intellectual Property and 26. Surface Texture 223 Engineering Design 19 27. Surface Finish and Corrosion 5. CAD Organization and Applications 23 of Metals 229 6. Principles of First and Third 28. 3DAnnotation 237 Angle Orthographic Projection 39 29. The Duality Principle e the 7. Linework and Lettering 53 Essential Link Between the Design 8. Three-dimensional Illustrations Intent and the Verification of Using Isometric and Oblique the End Product 243 Projection 59 30. Differences between American 9. Drawing Layouts and Simplified ASME Y 14.5M Geometric Methods 65 Dimensioning and Tolerancing 10. Sections and Sectional Views 77 (GD&T) and ISO/BS 8888 11. Geometrical Constructions and Geometrical Tolerancing Tangency 83 Standards 247 12. Loci Applications 89 31. Cams and Gears 253 13. True Lengths and Auxiliary Views 99 32. Springs 267 14. Conic Sections and Interpenetration 33. Welding and Welding Symbols 277 of Solids 105 34. Engineering Diagrams 283 15. Development of Patterns from 35. Bearings and Applied Technology 315 Sheet Materials 113 36. Engineering Adhesives 331 16. Dimensioning Principles 121 37. Related Standards 339 17. Screw Threads and Conventional 38. Production Drawings 347 Representations 131 39. Drawing Solutions 357 18. Nuts, Bolts, Screws and Washers 139 19. Keys and Key Ways 155 Index 363 v Chapter 1 Drawing Office Management and Organization Everyarticleusedinourday-to-dayliveswillprobably Engineering Industry. The first British Standard for have been produced as a result of solutions to Engineering Drawing Office Practice published in a sequence of operations and considerations, namely: September1927onlycontained14clauses,asfollows: 1. Conception 1. Sizes of drawings and tracings, and widths of 2. Design and analysis tracing cloth and paper 3. Manufacture 2. Position of drawing number, date and name 4. Verification 3. Indication of scale 5. In-service (maintenance) 4. Method of projection 6. Disposal. 5. Types of line and writing 6. Colour of lines The initial stage will commence when an original 7. Dimension figures marketable idea is seen to have a possible course of 8. Relative importance of dimensions development. The concept will probably be viewed 9. Indication of materials on drawings from an artistic and a technological perspective. 10. Various degrees of finish Theappearanceandvisualaspects ofaproductare 11. Screw threads very important in creating an acceptable good first 12. Flats and squares impression. 13. Tapers The technologist faces the problem of producing 14. Abbreviations for drawings. a sound, practical, safe design, which complies with the initial specification and can be produced at an There were also five figures illustrating: economical cost. 1. Method of projection During every stage of development there are many 2. Types of line progress records to be maintained and kept up to date 3. Views and sections sothatreferencetothecompletehistoryisavailableto 4. Screw threads responsible employees and regulatory bodies. 5. Tapers. Formanyyearsvarioustypesofdrawings,sketches and paintings have been used to convey ideas and Firstangleprojectionwasusedfortheillustrationsand information. In the last decade 3D models and rapid the publication was printed on A5 sheets of paper. prototypes have also become a common way of During the early days of the Industrial Revolution conveying design intent. However, a good recogniz- manufacturers simply compared and copied compo- able picture will often remove ambiguity when nentdimensionstomatchthoseusedontheprototype. a project is being discussed and assist in overcoming However,with theintroductionofquantityproduction a possible language barrier. where components were required to be made at BritishStandardsarelistedintheBritishStandards different factory sites, measurement by more precise Catalogue, and the earliest relevant Engineering means was essential. Individual manufacturers devel- Standards date back to 1903. Standards were devel- oped their own standard methods. Clearly, for the oped to establish suitable dimensions for a range of benefit of industry in general a National Standard was sizes of metal bars, sheets, nuts, bolts, flanges, etc. vital. Later the more comprehensive British Standard following the Industrial Revolution and used by the ofLimitsandFitswasintroduced.Therearetwoclear 1 2 ManualofEngineering Drawing aspects, which are necessary to be considered in the (a) The types of lines used must be of uniform specification of component drawings: thickness and density. (b) Eliminate fancy printing, shading and associated 1. The drawing shows the dimensions for the artistry. component in three planes. Dimensions of the (c) Includeonthedrawingonlytheinformationwhich manufactured component need to be verified isrequiredtoensureaccurateclearcommunication. because somevariation of size in each of the three (d) Use only standard symbols and where no other planes (length, breadth, and thickness) will be method of specification exist, appropriate unavoidable. The designer’s contribution is to abbreviations. provide a Characteristics Specification, which in (e) Ensure that the drawing is correctly dimensioned current jargon is defined as the ‘Design Intent (adequately but not over-dimensioned) with no Measurand’. unnecessary details. 2. The metrologist produces a ‘Characteristics Eval- uation’ which is simply the Measured Value. Remember that care and consideration given to small detailsmakeabigcontributiontowardsperfection,but Thedrawingofficeisgenerallyregardedastheheartof that perfection itself is no small thing. An accurate, any manufacturing organization. Products, compo- well-delineated engineering drawing can give the nents, ideas, layouts, or schemes which may be pre- draughtsman responsible considerable pride and job sented by a designer in the form of rough freehand satisfaction. sketches, may be developed stage by stage into Thefieldofactivityofthedraughtsmanmayinvolve working drawings and annotated 3D models by the the use, or an appreciation, of the following topics. draughtsman. There is generally very little construc- tive work which can be done by other departments 1. Company communications Most companies have within the firm without an approved drawing of some theirownsystemswhichhavebeendevelopedover form being available. The drawing is the universal a period of time for the following: means of communication. (a) internal paperwork; DrawingsaremadetoanacceptedStandard,andin (b) numbering of drawings and contracts; the United Kingdom, it is BS 8888, containing (c) coding of parts and assemblies; normative and informative references to international (d) production planning for component Standards. These Standards are acknowledged and manufacture; accepted throughout the world. (e) quality control and inspection; The contents of the drawing (and annotated 3D (f) updating, modification, and reissuing of models) are themselves, where applicable, in agree- drawings. ment with separate Standards relating to materials, 2. CompanystandardsManydrawingofficesusetheir dimensions, processes, etc. Larger organizations own standard methods which arise from satisfac- employStandardsengineerswhoensurethatproducts tory past experience of a particular product or conform to British and also international Standards process.Also,particularstylesmaybe retainedfor where necessary. Good design is often the product of easyidentification;e.g.,certainprestigecarscanbe teamworkwheredetailedconsiderationisgiventothe recognized easily since some individual details, in aesthetic,economic,ergonomicandtechnicalaspects principle, are common to all models. of a given problem. It is therefore necessary to 3. Standards fordimensioning Interchangeability and impose the appropriate Standards at the design stage, qualityarecontrolledbytheapplicationofpractical since all manufacturing instructions originate from limits, fits and geometrical tolerances. this point. 4. Material standards Physical and chemical proper- A perfect drawing communicates an exact ties and non-destructive testing methods must be requirement, or specification, which cannot be mis- borneinmind.Notemustalsobetakenofpreferred interpretedandwhichmayformpartofalegalcontract sizes,stocksizes,andavailabilityofrod,bar,tube, between supplier and user. plate, sheet, nuts, bolts, rivets, etc., and other Engineering drawings can be produced to a good bought-out items. professional Standard if the following points are 5. Draughting standards and codes of practice observed: Drawings must conform to accepted standards, but Chapter | 1 DrawingOfficeManagementand Organization 3 components are sometimes required which in supply, and the work involved can be classified as addition must conform to certain local require- follows. ments or specific regulations, for example relating 1. Engineering The engineering departments are tosafetywhenoperatingincertainenvironmentsor engaged in: conditions. Assemblies may be required to be (a) current production; flameproof, gastight, waterproof, or resistant to (b) development; corrosive attack, and detailed specifications from (c) research; the user may be applicable. (d) manufacturing techniques, which may include 6. Standard parts are sometimes manufactured in a study of metallurgy, heat-treatment, strength quantity by a company, and are used in several of materials and manufacturing processes; different assemblies. The use of standard parts (e) advanced project planning; reduces an unnecessary variety of materials and (f) field testing of products. basically similar components. 2. Sales This department covers all aspects of 7. Standards for costs The draughtsman is often marketing existing products and market research required to compare costs where different forfutureproducts.Thedrawingofficemayreceive methods of manufacture are available. A compo- work in connection with: (a) general arrangement nent could possibly be made by forging, by and outline drawings for prospective customers; casting, or by fabricating and welding, and (b) illustrations, charts and graphs for technical a decision as to which method to use must be publications; (c) modifications to production units made. The draughtsman must obviously be well to suit customers’ particular requirements; (d) awareofthemanufacturingfacilitiesandcapacity applicationandinstallationdiagrams;(e)feasibility offered by his own company and of the costs investigations. involved when different techniques of production 3. ServiceTheservicedepartmentprovidesareliable, are employed, and also have an idea of the likely prompt and efficient after-sales service to the costs when work is sub-contracted to specialist customer. The drawing office receives work asso- manufacturers, since this alternative often proves ciated with (a) maintenance tools and equipment; an economic proposition. (b) service kits for overhauls; (c) modifications to 8. Data sheets Tables of sizes, performance graphs, production parts resulting from field experience; and conversion charts are of considerable assis- (d) service manuals. tance to the design draughtsman. 4. Manufacturing units Briefly, these cover all Figure 1.1 shows the main sources of work flowing departments involved in producing the finished into a typical industrial drawing office. The drawing end-product. The drawing office must supply office provides a service to each of these sources of charts, drawings, schedules, etc. as follows: (a) working drawings of all the company’s products; (b) drawings of jigs and fixtures associated with Engineering manufacture; (c) plant-layout and maintenance drawings; (d) modification drawings required to aid production; (e) reissued drawings for updated equipment; Sales Doraffwicieng Service (f) drawings resulting from value analysis and works’suggestions. Figure1.2showstheorganizationinatypicaldrawing office.Thefunctionofthechiefdraughtsmanistotake overall control of the services provided by the office. Manufacturing The chief draughtsman receives all work coming into units the drawing office, which he examines and distributes to the appropriate sectionleader. The sectionleader is FIGURE1.1 4 ManualofEngineering Drawing which are relatively inexpensive for further planning, Chief draughtsman production and other uses. A library section will maintain and operate whatever archive arrangements are in operation. A large amount of drawing office workcomesfromcontinuousproductdevelopmentand Section modification, so easy access to past designs and rapid leaders information retrieval is essential. Technical Designers clerks s g Engineering Drawing Practices n wi Senior Standards dra Thecommentssofarrefertodrawingofficesingeneral draughtsmen section d he and typical organizational arrangements which are s Draughtsmen Checkers Fini likely to be found within the engineering industry. Goodcommunicationbytheuseofdrawingsofquality relies on ensuring that they conform to established Trainees Standards. BS5070,Parts1,3,and4dealingwithengineering Drawing office library diagram drawingpractice, is a companionStandardto BS8888andcatersforthesameindustries;itprovides Reprographic section recommendations on a wide variety of engineering diagrams. Commonly, as a diagram can be called a‘drawing’andadrawingcanbecalleda‘diagram’,it Manufacturing Sales Service Development units is useful to summarize the difference in the scopes of FIGURE1.2 these Standards. BS 8888 covers what are commonly accepted to be drawings that define shape, size and responsible for a team of draughtsmen of various form. BS 5070 Parts 1, 3, and 4 covers diagrams that grades. When work is completed, the section leader are normally associated with flow of some sort, and then passes the drawings to the checking section. The which relate components (usually indicated by Standards section scrutinizes the drawings to ensure symbols) functionally one to another by the use of thattheappropriateStandardshavebeenincorporated. lines, but do not depict their shape, size or form; All schedules, equipment lists, and routine clerical neithermaytheyingeneralindicateactualconnections work are normally performed by technical clerks. or locations. Completed work for approval by the chief Therefore, any drawing or diagram, whether draughtsman is returned via the section leader. produced manually or on computer aided draughting Since drawings may be produced manually, or by equipment,mustconformtoestablishedStandardsand electronic methods, suitable storage, retrieval and will then be of a satisfactory quality for commercial duplication arrangements are necessary. Systems in understanding,useand transmission by electronicand common use include: microfilming techniques. All of the examples which follow conform to the appropriate Standards. (a) filing by hand into cabinets the original master drawings, in numerical order, for individual DrawingPracticeandtheComputer(CAD: components or contracts; (b) microfilming and the production of microfiche; Computer Aided Draughting and Design) (c) computer storage. Thecomputerhasmadeafarbiggerimpactondrawing Thepreservationandsecurityoforiginaldocumentsis office practices than just being able to mimic the of paramount importance in industry. It is not normal traditional manual drawing board and tee square practicetopermitoriginalstoleavethedrawingoffice. technique. However, it depends on drawing office A drawing may take a draughtsman several weeks to requirements and if only single, small, two dimen- develop and complete and therefore has considerable sionaldrawingsandsketchesareoccasionallyrequired value. The reprographic staff will distribute copies and storage of originals is not an issue, then a manual Chapter | 1 DrawingOfficeManagementand Organization 5 drawing system may still be appropriate. CAD can you ask yourself the question ‘In 5, 10, or 15þ years’ however perform a much more effective role in the time,willIstillneedtomaintaintheelectronicproduct designprocessandmanyexamplesofitsabilityfollowe information?’ and the answer is ‘yes’ or ‘possibly’ but it will not do the work on its own. The input by then the following needs careful consideration. the draughtsman needs to follow the same standards The need to consider possible downstream appli- applied in the manual method and this fact is often cations such as Computer aided Machining (CAM), not understood by managers hoping to purchase CAD Inspection (CAI), and Analysis, i.e. finite element and obtain immediate answers to design enquiries. analysis (FEA), compatibility with existing systems The draughtsman needs the same technical appreci- (or the requirement to replace them) being very ation as before plus additional computingskills to use important. thevaried software programs which can be purchased. Compatibility with potential customer and sub- To introduce CAD, an organization must set out contractorsystemsshouldalsobeinvestigatedbecause clear objectives which are appropriate to their present if this is a controlling requirement then selection of and future requirements and Fig. 1.3 includes aspects a suitable system could be limited. of policy which could appear in such plans. The Longevity of the manufactured products will also following need consideration: play a significant role in system selection. In many areas of industry regulatory or contract requirements (a) CAD management roles; demandretentionofdesignrecordsforaperiodoftime (b) creation, training and maintenance of capable after the product is withdrawn from service. This CAD operators; period of time, when added to the length of service, (c) CAD awareness of design project team members could be considerable, i.e. in excess of 25 years. As in addition to their leaders; a result, costs associated with hardware and software (d) the flow of work through the system and the upgrades and system maintenance need to be consid- selecting of suitable types of project; ered.Insomecases,thecostsassociatedwithupgrades (e) associated documentation; can be offset against new products, but nevertheless, (f) possible changes to production methods; ongoing maintenance of legacy databases can be (g) needs involving the customer and sub-contractor; costly. It is interesting to note that this was a problem (h) system needs relating to planning, security and that was often not foreseen in the early days of CAD. upgrading; The rush by industry to move from the drawing board (i) CAD library and database (storage of drawings, toCADhas,insomecases,ledtocompanieschanging symbols, etc.) and archive procedures; CAD systems and struggling to maintain legacy (j) configuration management. drawings without costly redraws. Even today, with WhenintroducingorreplacingaCADsystemitisvery some very good CAD file translators on the market, important to take time to consider points (f) to (i) as 100%datatransfercan’talwaysbeguaranteedwithout thesecanhaveamajorimpactonthroughlifecosts.If some remedial work. A possible solution for consideration could be maintaining the drawings of a stable product on microfilm or possibly an enduring electronic format Feedback suchasAdobeAcrobatfiles(.PDF).Somecompanies are already future proofing their design information Company application. Design, manufactu- by retaining drawings and models in their native ring, sales and service CAD format and also in .PDF format and on compCuotmerp satnraytegy Organization Imcpolemmmeunntaictiaotnio annd microfilm. and policy for and methods systems for all Configuration control is also equally important to 5-year term users CADsystemsasitistomanualsystemsandextracare Hardware needs to be taken to ensure unauthorized access to master files. Software Performance Many similar aspects will be appropriate in monitoring Resources and control particular applications but good intentions are not FIGURE1.3 Generalcomputerpolicyrelationships. sufficient. It is necessary to quantify objectives and