1、 ASME B94.9-2008(Revision of ASME B94.9-1999)Taps: GroundThread With CutThread Appendix(Inch and MetricSizes)AN AMERICAN NATIONAL STANDARDDate of Issuance: June 30, 2009This Standard will be revised when the Society approves the issuance of a new edition. There willbe no addenda or written interpret
2、ations of the requirements of this Standard issued to this edition.PeriodicallycertainactionsoftheASMEB1CommitteewillbepublishedasCases.Casesarepublishedon the ASME Web site under the Committee Pages at http:/cstools.asme.org as they are issued.ASME is the registered trademark of The American Societ
3、y of Mechanical Engineers.This code or standard was developed under procedures accredited as meeting the criteria for American NationalStandards. The Standards Committee that approved the code or standard was balanced to assure that individuals fromcompetent and concerned interests have had an oppor
4、tunity to participate. The proposed code or standard was madeavailableforpublicreviewandcommentthatprovidesanopportunityforadditionalpublicinputfromindustry,academia,regulatory agencies, and the public-at-large.ASME does not “approve,” “rate,” or “endorse” any item, construction, proprietary device,
5、 or activity.ASME does not take any position with respect to the validity of any patent rights asserted in connection with anyitems mentioned in this document, and does not undertake to insure anyone utilizing a standard against liability forinfringement of any applicable letters patent, nor assumes
6、 any such liability. Users of a code or standard are expresslyadvised that determination of the validity of any such patent rights, and the risk of infringement of such rights, isentirely their own responsibility.Participation by federal agency representative(s) or person(s) affiliated with industry
7、 is not to be interpreted asgovernment or industry endorsement of this code or standard.ASME accepts responsibility for only those interpretations issued in accordance with the established ASME proceduresand policies, which precludes the issuance of interpretations by individuals.No part of this doc
8、ument may be reproduced in any form,in an electronic retrieval system or otherwise,without the prior written permission of the publisher.The American Society of Mechanical EngineersThree Park Avenue, New York, NY 10016-5990Copyright 2009 byTHE AMERICAN SOCIETY OF MECHANICAL ENGINEERSAll Rights Reser
9、vedPrinted in U.S.A.CONTENTSForeword vCommitteeRoster . viCorrespondenceWiththeB94Committee vii1 General . 12 Tap Categorization. 13 Tap Styles. 44 Standard System of Tap Marking 75 Standard System of Tap Thread Units and Identification, Ground Thread. 76 Glossary of Tap Elements and Other Terms Rel
10、ated to Screw Threads . 8Figures1 IllustrationsofTermsApplyingtoTaps . 22 StraightFluteStyleTaps 53 SpiralPointedStyleTaps . 54 SpiralPointedOnlyStyleTaps 55 RegularSpiralFlutedStyleTaps 56 FastSpiralFlutedStyleTaps 67 ThreadFormingTypeTaps . 68 PulleyTypeTaps . 69 PipeTypeTaps . 7Tables1 ThreadSeri
11、esDesignations . 192 StandardTapDimensions . 203 OptionalNeckandOptionalShortenedThreadLength(TapDimensions) 234 StandardTapDimensionsScrewThreadInserts(STI):MachineScrewandFractionalSizeTaps . 255 StandardTapDimensionsScrewThreadInserts(STI),MetricSizeTaps . 276 StraightandTaperPipeTaps . 297 TapTh
12、readLimitsandTolerances,FormulasforUnifiedInchScrewThreads(GroundThread) . 318 StandardChamfersforThreadCuttingTaps. 339 StandardEntryTaperLengthsforThreadFormingTaps . 3410 TapThreadLimitsandTolerances,FormulasforMetricThreads(GroundThread) 3511 StandardNumberofFlutes . 3712 TapThreadLimits:Machine
13、ScrewSizes,GroundThread(UnifiedandAmericanNationalThreadForms,StandardThreadLimits) . 3913 TapThreadLimits:FractionalSizes,GroundThread(UnifiedandAmericanNationalThreadForms,StandardThreadLimits) . 4014 TapThreadLimits:MetricSizes,GroundThread(MProfile:StandardThreadLimitsinMillimeters) . 4215 Runou
14、tofTapElements 4416 PulleyTaps,FractionalSize(High-SpeedSteel,GroundThread) 4517 TaperPipeTapThreadLimits(GroundThread;GroundThreadforNPT,NPTF,andANPT) . 4618 StraightPipeTapThreadLimits:NPSC/NPSM,GroundThreadAmericanNationalStandardStraightPipeThreadForm(NPSC,NPSM) 48iii19 StraightPipeTapThreadLimi
15、ts:NPSF,GroundThreadDrysealAmericanNationalStandardStraightPipeThreadForm(NPSF) 4920 TapThreadLimitsScrewThreadInserts(STI),GroundThread,MachineScrew,andFractionalSize. 5021 TapThreadLimitsScrewThreadInserts(STI),GroundThread,MetricSize(mm) 52Nonmandatory AppendicesA TapSizeRecommendations . 53B Sta
16、ndardSystemofTapMarkingCutThreadTaps 72ivFOREWORDAsubcommitteeoftheNationalScrewThreadCommissionbeganstandardizingcertaindimen-sionsofcutandgroundthreadtapsin1926.Thesubcommitteepreparedareportthatwasfinallyreferred to the sectional committee on Small Tools and Machine Tool Elements (B5) organizedun
17、dertheprocedureoftheAmericanStandardsAssociation(ASA).TheoriginalproposalpassedthroughtheregularprocedureandwasdesignatedasanAmericanStandardbyASAinApril1930.Followingthepublicationofthestandardin1930,TechnicalCommittee12onCutandGroundThreadTapsdecidedtoincludeinthenexteditionadditionaltypesandsizes
18、,aglossaryoftermsanddefinitions,andcertaincommercialstandardsissuedbythetapanddiemanufacturersthatwerereproducedfromtheirpublications.Followingapprovalfromthesectionalcommitteeandthesponsors,theproposalwasapprovedbyASAinNovember1939.In1962anewsectionalcommittee,B94,wasformedforthestandardizationofcu
19、ttingtools.TechnicalCommittee12onCutandGroundThreadTapsnowoperateswithinthisframework.In1967therevisedStandardproposedbyTechnicalCommittee12wasapprovedanddesignatedB94.9-1967.In1971therevisedStandardproposedbyTechnicalCommittee12wasapprovedanddesignatedB94.9-1971.In1979therevisedStandardproposedbyTe
20、chnicalCommittee12wasapprovedanddesignatedB94.9-1979.In1987therevisedStandardproposedbyTechnicalCommittee12wasapprovedfollowingallthe procedures of the American National Standards Institute (ANSI) and designated ASME/ANSIB94.9-1987.In1999therevisedStandardproposedbyTechnicalCommittee12wasapprovedand
21、designatedASMEB94.9-1999.In2005therevisedStandardproposedbyTechnicalCommittee12wasapprovedanddesignatedASMEB94.9-2008.Thefollowingmajorchangestothestandardincludedare:(a) ASMEB94.9isnowundertheB1StandardsCommittee.ThisStandardwillstillhavetheB94.9designation.(b) Alltablesforcutthreadtapshavebeenmove
22、dtotheAppendixsectionofthisStandard.(c) STIsizetapshavehadblanksizesrevisedtobeconsistentwithstandardindustrypractice.ThemajordiametervaluesonmetricSTItapswillfollowestablishedvalues,andpitchdiametervaluesofmetricSTItapswillremainlistedwith“H”pitchdiameterlimits.(d) Theterm“leadtolerance”hasbeenchan
23、gedto“cumulativepitcherror,”andformulasforcalculatingthevaluesareincludedinthisStandard.(e) ThepracticeofmarkingtapsNPShasbeenchangedtoNPSC/NSPM.(f) The practice of marking taps NC, NF, NEF, NS has been changed to UNC, UNF, UNEF,UNSformachinescrewandfractionssizes.(g) TheinclusionofHS(highspeedsteel
24、)andG(groundthread)hasbeenmadeoptionalinthemarkingoftaps.(h) Nomenclature definitions for high speed steel, ground thread taps, and cut thread tapshavebeenaddedThisStandardwasapprovedasanAmericanNationalStandardonJune18,2008.vASME B1 COMMITTEEScrew Threads(The following is the roster of the Committe
25、e at the time of approval of this Standard.)STANDARDS COMMITTEE OFFICERSA. L. Barrows, ChairD. S. George, Vice ChairA. L. Guzman, SecretarySTANDARDS COMMITTEE PERSONNELA. L. Barrows, Kennametal Industrial Products GroupL. C. Borowski, Greenslade and Company, Inc.F. G. Calderone, Contributing Member,
26、 Quality SystemsImplementersR. Dodge, Pennoyer Dodge Co.D. Everett, National Institute of Standards and TechnologyJ. O. Gehret, Vermont Thread Gage, LLCD. S. George, ND IndustriesJ. R. Gervasi, Kerr Lakeside, Inc.J. Greenslade, Industrial Fasteners InstituteA. L. Guzman, The American Society of Mech
27、anical EngineersR. J. Hukari, SPS TechnologiesL. C. Johnson, The Johnson Gage Co.D. D. Katz, Precision FittingsR. P. Knittel, Leitech-US, Ltd.SUBCOMMITTEE B94.9 TAPSA. D. Shepherd, Jr., Chair, Emuge Corp.A. L. Barrows, Kennametal Industrial Products GroupS. R. Burns, Greenfield IndustriesR. Dodge, P
28、ennoyer Dodge Co.D. D. Gajdosik, Besly Products Corp.viP. A. Larouche, Micron Company, Inc.M. H. McWilliams, PMC Lone StarD. R. Maisch, Alternate, PMC Lone StarD. Miskinis, Kennametal Industrial Products GroupD. R. Oas, Seaway Bolt and Specials Corp.M. W. Rose, Glastonbury Southern GageW. A. Watts,
29、Alternate, Glastonbury Southern GageE. Schwartz, ConsultantB. F. Sheffler, Dresser-Rand Co.A. D. Shepherd, Jr., Emuge Corp.D. Skierski, Sterling Gage and Calibration, LLCR. D. Strong, General MotorsA. F. Thibodeau, Honorary Member, Swanson Tool Manufacturing,Inc.R. E. Vincent, Jr., General Plug and
30、Manufacturing Co.C. J. Wilson, ConsultantD. S. George, ND IndustriesM. N. Jarvis II, Jarvis Cutting Tools, Inc.D. Miskinis, Kennametal Industrial Products GroupK. A. Nelson, Dauphin Precision Tool, LLCCORRESPONDENCE WITH THE B1 COMMITTEEGeneral. ASME Standards are developed and maintained with the i
31、ntent to represent theconsensusofconcernedinterests.Assuch,usersofthisStandardmayinteractwiththeCommitteebyproposingrevisions,andattendingCommitteemeetings.Correspondenceshouldbeaddressedto:Secretary,B1StandardsCommitteeTheAmericanSocietyofMechanicalEngineersThreeParkAvenueNewYork,NY10016-5990Propos
32、ing Revisions. RevisionsaremadeperiodicallytotheStandardtoincorporatechangesthatappearnecessaryordesirable,asdemonstratedbytheexperiencegainedfromtheapplicationoftheStandard.Approvedrevisionswillbepublishedperiodically.TheCommitteewelcomesproposalsforrevisionstothisStandard.Suchproposalsshouldbeas s
33、pecific as possible, citing the paragraph number(s), the proposed wording, and a detaileddescriptionofthereasonsfortheproposal,includinganypertinentdocumentation.Proposing a Case. Cases may be issued for the purpose of providing alternative rules whenjustified,topermitearlyimplementationofanapproved
34、revisionwhentheneedisurgent,ortoprovide rulesnot covered byexisting provisions. Casesare effective immediatelyupon ASMEapprovalandshallbepostedontheASMECommitteeWebpage.RequestsforCasesshallprovideaStatementofNeedandBackgroundInformation.Therequestshould identify the Standard, the paragraph, figure
35、or table number(s), and be written as aQuestionandReplyinthesameformatasexistingCases.RequestsforCasesshouldalsoindicatetheapplicableedition(s)oftheStandardtowhichtheproposedCaseapplies.Attending Committee Meetings. TheB1StandardsCommitteeregularlyholdsmeetings,whichareopento thepublic.Personswishin
36、gtoattend anymeetingshouldcontactthe SecretaryoftheB1StandardsCommittee.viiASME B94.9-2008TAPS: GROUND THREAD WITH CUT THREAD APPENDIX(INCH AND METRIC SIZES)1 GENERAL1.1 ScopeThisStandardcoversvariousdesignsofstandardtaps,nomenclature, anddefinitions; thestandard systemofmarking; and dimensions and
37、tolerance tables for thetypesandstylesoftapslistedbelow.Forthreadseriesdesignations,refertoTable1.ApplicableType Style Section(s)Standardstraight Straightfluted 3.1thread,general Spiralfluted 3.4and3.5purpose;Tables Spiralpoint,with 3.22,3,and4 straightflutesSpiralpointonly, 3.3nostraightflutesStrai
38、ghtfluted 3.1Pulley;Table6 Straightfluted 3.7Pipe,taperthread; Straightfluted 3.8Table7Pipe,straight Straightfluted 3.8thread;Table10Threadforming; Straightlobes 3.6Tables2and3 Spirallobes 3.61.2 Reference Standards for Screw ThreadNomenclature and Forms of ThreadThe following is a list of publicati
39、ons referenced inthisStandard.ASMEB1.1,UnifiedInchScrewThreads(UNandUNRThreadForm)ASMEB1.7,ScrewThreads:Nomenclature,Definitions,andLetterSymbolsASMEB1.12,Class5Interference-FitThreadASMEB1.13M,MetricScrewThreadsMPr ofileASMEB1.15,UnifiedInchScrewThreads(UNJThreadForm)ASMEB1.20.1,PipeThreads,General
40、Purpose(Inch)ASMEB1.20.3,DrysealPipeThreads(Inch)ASMEB1.20.7,HoseCouplingScrewThreads(Inch)ASMEB1.21M,MetricScrewThreads:MJProfileASMEB1.30,ScrewThreadsStandardPracticeforCalculatingandRoundingDimensionsASME B18.29.1, Helical Coil Screw Thread Inserts FreeRunningandScrewLocking(InchSeries)1Publisher
41、: The American Society of MechanicalEngineers (ASME), Three Park Avenue, New York,NY10016-5990;OrderDepartment:22LawDrive,P.O.Box2300,Fairfield,NJ07007-2300SAE AS-8879, Screw Threads-UNJ Profile InchControlled Radius Root With Increased MinorDiameterSAEAS-71051,PipeThreadsTaper,AeronauticalNationalF
42、orm,SymbolANPT-DesignandInspectionStandardPublisher:SocietyofAutomotiveEngineers(SAE),400CommonwealthDrive,Warrendale,PA15096-00011.3 Basic Form of ThreadThebasicangleofthreadbetweentheflanksofthreadmeasuredinanaxialplaneis60deg(Fig.1).Thesymmetricalheightofthethreadform,h,isfoundasfollows:h p 0.649
43、51905P p0.64951905nThebasicpitchdiameterisobtainedbysubtractingthesymmetricalsinglethreadheight,h,fromthebasicmajordiameterasfollows:Basicpitchdiameter p DbschwhereDbscp basicmajordiameterh p symmetricalheightofthreadn p numberofthreadsperinchP p pitchofthread1.4 Tap Pitch Diameter SizeArangeoftappi
44、tchdiameterlimitsfromwhichtheusermayselecttosuitlocalconditionsisavailable.TablesA-1andA-2inNonmandatoryAppendixAlisttappitchdiameterlimitsthatproducecommonclassesof thread when used with reasonable care in averagematerials.Factorsbeyondthetap“H”limitaffectfinalpartsize.2 TAP CATEGORIZATIONTapsinclu
45、dedinthisStandardarecategorizedaccording to type, style, size and chamfer, and blankASME B94.9-2008Fig. 1 Illustrations of Terms Applying to TapsOverall length, LOverall length, LOverall length, LOverall length, LThreadlength,lShank length, l4Shank length, l4Necklength, l1Neckdiameter d2Drivingsquar
46、elength Drivingsquarelength Drivingsquarelength Driving squarelength l2Chamferlengthl5Blank Design 2(without optional neck)Blank Design 2(with optional neck)Blank Design 1Blank Design 3TruncatedcenteroptionalTransition optionalwith manufacturerTransition neck to shank optional with manufacturerFlute
47、Core diameterLand widthThreadlength,lShank length, l4Shank length, l4Shank diameterd1l2l2d3PointdiameterSize of squareacross flatsaThread lead angleChamferangleInternal centers(both ends)Threadlength,lExternal centersThreadlength,l90 degl22ASME B94.9-2008Fig. 1 Illustrations of Terms Applying to Tap
48、s (Contd)PitchTap crestFlankBasic crestBasic rootMinimum tap majordiameterBasicmajordiameter, dBasicpitchdiameterBasicheight ofthreadBasicminor diameterConcentricmarginEccentricreliefCon-eccentricReliefEccentricReliefConcentricPositiveHook0-deg HookNegativeHookPositiveRakeRadialRakeNegativeRakeRelie
49、ved tocutting edgeCutting edgeCutting faceTap majordiameterBasic minordiameterNo reliefHeelBase of threadAngle of threadMaximum tap majordiameter3ASME B94.9-2008design, which are explained further in the followingparagraphs.2.1 TypeTaptypeisbasedonsuchgeneraldimensionsasstan-dardstraightthread,taperandstraightpipe,pulley,etc.,or is based on purpose, such as thread forming andscrewthreadinsert(STI).Seepara.1.1.2.2 StyleTap style is based on flute construction for cuttingtaps,suchasstraight,spira
