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ASME Y 14.5M-1994 - Dimendioning ...ASME Y 14.5M-1994 - Dimendioning And Tolerancing, Engineering
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//-->AN ASME NATIONALENGINEERINGSTANDARDDRAWINGAND RELATED DOCUMENTATIONPRACTICESDimensioningandTolerancingASME Y14.5M-1994[REVISIONOF ANSI Y14.5M-1982(RI98811The American Society ofMechanical Engineers345 East 47 th Street, New York, N.Y.Date of Issuance: January 23, 1995This Standard will be revised when the Society approves the issuance of anew edition. There will be no addenda or written interpretations of the require-ments of this Standard issued to this edition.ASME is the registered trademark of The American Society of Mechanical Engineers.This code or standard was developed under procedures accredited as meeting the criteria forAmerican National Standards. The Consensus Committee that approved the code or standard wasbalanced to assure that individuals from competent and concerned interests have had an opportu-nity to participate. The proposed code or standard was made available for public review andcomment which provides an opportunity for additional public input from industry, academia,regulatory agencies, and the public-at-large.ASME does not “approve,” “ rate,” or “endorse” any item, construction, proprietary device, oractivity.ASME does not take any position with respect to the validity of any patent rights asserted inconnection with any items mentioned in this document, and does not undertake to insure anyoneutilizing a standard against liability for infringement of any applicable Letters Patent, nor assumeany such liability. Users of a code or standard are expressly advised that determination of thevalidity of any such patent rights, and the risk of infringement of such rights, is entirely their ownresponsibility.Participation by federal agency representative(s) or person(s) affiliated with industry is not tobe interpreted as government or industry endorsement of this code or standard.ASME accepts responsibility for only those interpretations issued in accordance with governingASME procedures and policies which preclude the issuance of interpretations by individualvolunteers.No part of this document may be reproduced in any form,in an electronic retrieval system or otherwise,without the prior written permission of the publisher.THE AMERICANCopyright 0 1995 bySOCIETY OF MECHANICALAll Rights ReservedPrinted in the U.S.A.ENGINEERS(This Foreword is not a part of ASME Y14.5M-1994.)Additions,modifications,and clarification containedin this revision of ANSI Y 14.5M-1982 are intendedto improve national and internationalstandardization to harmonizeandthe United Statespracticesand methodology with the universal standardstrend towardmore efficient worldwide technical communication.Coordinating and integrating thesetechniquesinto and via computer graphicsand other electronic data systemsfor design,manufacture,verification, and similar processes also a prime objective.isIncorporatingthis Standardas a vehicle to assistthe United States’active participationand competitiveness the world marketplaceis a major goal. The emergenceof prioritiesinon total quality management,world-class engineering, and emphasison compatibilitywith the International Organization for Standardization(ISO) 9000 series of qualitystandards had a significantinfluence in the work of the Y14.5 Subcommittee.hasThis revision was initiated immediately after the official release of ANSI Y14.5M-1982 in December 1982 in responseto deferred comments from that revision, newconceptual developments, new symbology, and international standards expansion.Twenty-three Subcommittee meetings and numerous working group meetings of theASME Y 14.5 Subcommitteewere convenedduring the developmentalperiod. The meet-ings were held in various cities aroundthe United States.The Subcommittee’ work wasscoordinatedas much as possiblewith other related ASME committeesand other standarddeveloping bodies that share a common purpose on dimensioning and tolerancing orrelated standards.Particularly close alliance and liaison were sought with the ASMEB89 Committee on “Dimensional Metrology,” and new committeesASME Y14.5.1 on“Mathematical Definition of Y 14.5,” and ASME Y14.5.2 on “Certification of GD&TProfessionals.”Of high priority was the continuingUnited Statesparticipationin the developmentofIS0 standardsthrough its U.S. member body, the American National StandardsInstitute(ANSI). Some members of the Y14.5 Subcommitteehave attendedand participatedinnumerousinternationalmeetingsand activities during and since the last revision of thisStandard.Meetings were attendedin Paris, France (1981), West Berlin, Germany (1982);New York City, New York (1984), West Berlin, Germany (1987), Zurich, Switzerland(1989), Orlando, Florida (1991), and Carmel, California (1992). United Statesdelegateshave served as members and convenersof Working Groups, chaired some TClO/SCS...111internationalmeetingsand have participatedin all IS0 standardsprojects on the subjectof dimensioningand tolerancing during this period.In addition to past participation in developing and maintaining all of such IS0 stan-dardsas IS0 5458, IS0 5459, IS0 2692, IS0 3040, IS0 TR 5460, IS0 1660, IS0 406,IS0 129, IS0 8015, and IS0 7083, U.S. delegateshave also participatedin all new IS0standardsdevelopmentprojects. U.S. delegateshave provided convenership(chairman-ship) to the developmentof ISO/2692: 1988 DAM1 on “Least Material Condition,” IS010578 on “Projected Tolerance Zone,” and IS0 10579 on “Nonrigid Parts.” Currentprojectsrelated to the revision of IS0 1101, “Technical Drawings, Geometrical Toleranc-ing” and IS0 5458, “Positional Tolerancing” also have participation and input by U.S.delegates.Current new work on a revision to IS0 2692 includes considerationof the“principle of reciprocity” (symbol 8) that was originally put forth by the U.S. and Japanin the early 1970’ as a proposedstandard.It was consideredby some countriesto bespremature for inclusion then and zero positional tolerancing was adopted as a nearsubstitute.As a recent significant development, the United States, through its member body,ANSI, has received the ISO/TClO/SC5 Secretariat. Thus, the U.S. inherits the worldleadership for standardsdevelopment on “Technical drawings, product definition andrelated documentation,geometrical dimensioningand tolerancing.” Work will continueon maintenanceof existing standardsand the development of new standardsrelated togeometrical tolerancing.The conflict in principle regarding limits of size between the “envelope principle”(Taylor Principle, Rule #l) and the “independencyprinciple” continues,althoughsome-what abated.Issuanceof IS0 8015:1985, “Technical Drawings-FundamentalTolerancingPrinciple,” features the independencyprinciple but allows the option of the envelopeprinciple by either reference to a national standard(for example, ASME Y14.5M-1994)on the drawing, or by invoking the symbol 6. The Y 14.5 Standardcontinuesto advocateand use the envelope principle (boundary of perfect form at MMC of the individualfeature) that has been traditionally used in the U.S. and widely acceptedelsewhere.The least material condition 0 conceptis expanded.More complete coverage on thissubjectis to be consideredin future revisions as the state of the art progresses.Significant stepsare taken in this revision to resolve some long-standingdifferencesbetween the Y14.5 and IS0 practices.As U.S. delegatesalso play a significant role inthe developmentand maintenanceat the level of internationalstandards,thesedifferencesare eventually temperedand resolved by a merging of these dual objectives.In addition,some long-rangeplanning by the Y 14.5 activity has also now materialized in the transi-tion to eliminating these differences. Two significant changesfound in this revision areadoptionand extensionof the universal datum feature symbol and discontinuance theofuse of the RFS symbol 0. Other changes,additions,extensions principles,and resolu-oftion of differences are listed in Appendix A, “Principal Changesand Improvements.”The technical expertise and experience of the Y14.5 Subcommitteeare provided bythe dedicated interests and resourcesof its personnel. Its members represent a broadcross section of U.S. industry, the Department of Defense (DOD), educationalinstitu-tions, national laboratories,professional societies, and members of the private sector.The Subcommittee encouragesparticipation by all and works diligently to achieve aconsensuson all matters. It seeks a balance between past practices, state of the art,nationaland internationalstandards,new technology,computerand electronicintegration,and most importantly, the understandabilityof the technical data containedin the Stan-dard itself. Since membersare also usersof the Standard,a “jury of peers”is constantlypresentto ensure,as well as possible,that all voices are heard and satisfactorycompro-mises are made in the interestsof all users.Through the due processof final approvaliv [ Pobierz całość w formacie PDF ] |
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