1、ASME B1.30-2002(Revision of ASME B1.30M-1992)ASME B1.30-2002(Revision of ASME B1.30M-1992)SCREW THREADS:STANDARD PRACTICEFOR CALCULATINGAND ROUNDINGDIMENSIONSSCREW THREADS:STANDARD PRACTICEFOR CALCULATINGAND ROUNDINGDIMENSIONSAN AMERICAN NATIONAL STANDARDREAFFIRMED 2017Intentionally left blank AN AM
2、ERICAN NATIONAL STANDARDSCREW THREADS:STANDARD PRACTICEFOR CALCULATINGAND ROUNDINGDIMENSIONSASME B1.30-2002Revision of ASME B1.30M-1992Date of Issuance: April 25, 2003This Standard will be revised when the Society approves the issuance of a new edition. There willbe no addenda or written interpretat
3、ions of the requirements 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 for American NationalStandards. The Standards Committee that appro
4、ved the code or standard was balanced to assure that individuals fromcompetent and concerned interests have had an opportunity to participate. The proposed code or standard was madeavailableforpublicreviewandcommentthatprovidesanopportunityforadditionalpublicinputfromindustry,academia,regulatory age
5、ncies, and the public-at-large.ASME does not “approve,” “rate,” or “endorse” any item, construction, proprietary device, 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 underta
6、ke to insure anyone utilizing a standard against liability forinfringement of any applicable letters patent, nor assume 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, isen
7、tirely their own responsibility.Participation by federal agency representative(s) or person(s) affiliated with industry is not to be interpreted asgovernment or industry endorsement of this code or standard.ASME accepts responsibility for only those interpretations of this document issued in accorda
8、nce with the establishedASME procedures and policies, which precludes the issuance of interpretations by individuals.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 American Society of Mec
9、hanical EngineersThree Park Avenue, New York, NY 10016-5990Copyright 2003 byTHE AMERICAN SOCIETY OF MECHANICAL ENGINEERSAll rights reservedPrinted in U.S.A.CONTENTSForeword ivCommitteeRoster v1 General . 12 Rounding of Decimal Values 13 Calculations From Formulas 24 Thread Form Constants . 2Tables1
10、NumberofDecimalPlacesUsedinCalculations 22 ExampleofExternalInchScrewThreads,12-28UNEF-2A. 43 ExampleofInternalInchScrewThreads,12-28UNEF-2B 74 ExampleofExternalInchScrewThreads,1964-36UNS-2A. 95 ExampleofInternalInchScrewThreads,1964-36UNS-2B 126 ExampleofExternalMetricScrewThreads,M12H115471.75-4g
11、6g . 147 ExampleofInternalMetricScrewThreads,M12H115471.75-6H 168 ExampleofExternalMetricScrewThreads,M13H115470.9-4g6g 189 ExampleofInternalMetricScrewThreads,M13H115470.9-6H. 2010 ThreadFormData. 22Nonmandatory AppendixA ThreadCharacteristicsGovernedbythisStandard 23iiiFOREWORDTheAmericanNationalS
12、tandardsCommitteeB1forstandardizationofscrewthreadswasorganizedin1920assectionalCommitteeB1underthesponsorshipoftheAmericanEngineeringStandardsCommittee(latertheAmericanStandardsAssociation,thentheUnitedStatesofAmericaStandardsInstituteandasofOctober6,1969,theAmericanNationalStandardsInstitute,Inc.)
13、,withtheSocietyofAutomotiveEngineersandTheAmericanSocietyofMechanicalEngineersas joint sponsors. As a result, a great deal of effort was expended through the years towarddevelopmentofseveralscrewthreadstandards.Recognizingtheneedtostandardizethemethodofroundingdecimalvaluesinthecalculationofscrewthr
14、eaddimemsions,theASMEStandardsCommitteeB1chargedSubcommittee30withtheresponsibilityforproducingsuchastandard.ThisStandarddesignatedASMEB1.30wasdevelopedonlytoserveasthebasisforroundingofdecimalvaluesassociatedwiththecomputationofscrewthreaddimensions.The examples and formulas depicted within this St
15、andard are for reference only and arepresentedonlytoclarifytheroundingproceduresdescribed.Whencalculatingthedifferentthreadcharacteristicsforaparticularthreadform,refertotheappropriateASMEB1standardfortheformulasandmethodologyofcalculationforthatthread.ThisStandardwasoriginallyapprovedasanAmericanNa
16、tionalStandardonJune29,1992.Thisissueupdatesthe1992issueandincludes:(a) theadditionofanotetopara.1.2fortheclarificationoftheuseofthisStandardformetricapplications;(b) theadditionofanexceptioninpara.3.1.3tothenumberofdecimalplacesfortheallowance2AwhenusedinintermediatecalculationsasTd2;(c) theadditio
17、nofthemaximumexternalUNminordiameter,maximumandminimuminternalpitchdiametersandtheminimuminternalmajordiametertotheexampleinpara.3.2.1;(d) removal of Appendix A containing various common values for 60 deg thread elements.This was done because the values are either listed or can be calculated by form
18、ulas in otherexistingB1standards;(e) theadditionofanexampleforastandardmetricsizethatislistedinASMEB1.13MandISO261;(f) theadditionofanexampleforaspecialinchsizeshowinghowtoroundnumberswithaninfinitenumberofdigitsafterthedecimalpoint;(g) added a new Appendix A with a table listing the number of decim
19、al places for each ofthethreadcharacteristicsusedintheexamplesinB1.30.SuggestionsforimprovementofthisStandardwillbewelcome.TheyshouldbesenttoSecretary,ASMEB1StandardsCommittee,ThreeParkAvenue,NewYork,NY10016-5990U.S.A.ThisrevisionwasapprovedasanAmericanNationalStandardonJuly12,2002.ivASME STANDARDS
20、COMMITTEE B1Standardization and Unification of Screw Threads(The following is the roster of the Committee at the time of approval of this Standard.)OFFICERSA. L. Barrows, ChairD. S. George, Vice ChairJ. R. Bird, SecretaryCOMMITTEE PERSONNELG. L. Allen, The L. S. Starrett Co.A. L. Barrows, Kennametal
21、-IPGM. H. Bernier, Standard Nut and BoltJ. R. Bird, The American Society of Mechanical EngineersF. G. Calderone, Quality Systems ImplementersJ. Davis, U.S. Nuclear Regulatory CommissionL. N. Dixon, Jr., General ElectricR. Dodge, Pennoyer-Dodge Co.G. A. Flannery, Mercury Gage Co.D. Skierski, Alternat
22、e, Mercury Gage Co.H. N. Frost, Defense Supply Center PhiladelphiaD. S. George, Ford Motor Co.J. R. Gervasi, Kerr Lakeside Inc.J. Greenslade, Greenslade EXAMPLE:1.01235 1.01241.0123500 1.01241.012345 1.012351.01234500 1.01235(b) ifthe5nextbeyondthefigureinthelastplacetoberetainedarefollowedbyanyfigu
23、resotherthanzero,ASME B1.30-2002 SCREW THREADS: STANDARD PRACTICE FORCALCULATING AND ROUNDING DIMENSIONSTable 1Number of Decimal Places Used in CalculationsUnits Pitch Constants Intermediate FinalInch 8 8 6 4 (except as outlined in para. 3.1.3)Metric as designated 7 5 3thefigureinthelastplaceretaine
24、dshouldbeincreasedby1.EXAMPLE:1.0123501 1.01241.0123599 1.01241.01234501 1.012351.01234599 1.012352.1.4 Thefinalroundedvalueisobtainedfromthemost precise value available and not from a series ofsuccessiverounding.Forexample,0.5499shouldberoundedto0.550,0.55and0.5(not0.6),sincethemostprecisevalueavai
25、lableislessthan0.55.Similarly,0.5501shouldberoundedas0.550,0.55and0.6,sincethemostprecisevalueavailableismorethan0.55.Inthecaseof0.5500roundingshouldbe0.550,0.55and0.6,sincethemostprecisevalueavailableis0.5500.3 CALCULATIONS FROM FORMULAS3.1 General Rules3.1.1 Valuesforpitchandconstantsderivedfromaf
26、unction of pitch are used out to eight decimal placesforinchseries.Theeightplacevaluesareobtainedbyroundingtheirtruncatedtenplacevalues.Sevendecimalplacevaluesformetricseriesconstantsarederivedbyroundingtheirtruncatednineplacevalues.Seepara.4forthreadformconstants.Valuesusedinintermediatecalculation
27、sareroundedtotwoplacesbeyondthenum-ber of decimal places retained for the final value, seeTable1.EXAMPLE:np28threadsperinchPp1/nPp1/28Pp0.0357142857Pp0.035714293.1.2 Roundingtothefinalvalueisthelaststepinacalculation.3.1.3 Forinchscrewthreaddimensions,fourdecimalplacesarerequiredforthefinalvaluesofp
28、itchdiameter,majordiameter,andminordiameterwiththeexceptionofClass1Band2Binternalthreadminordiametersforthreadsizes0.138andlarger,seebelow.Thefinalvaluesfortheallowancesandtolerancesappliedtothreadele-ments are expressed to four decimal places except for2externalthreadpitchdiametertolerance,Td2,whic
29、hisexpressedtosixdecimalplaces.(a) MinorDiameterExceptionsforInternalThreads:(1) MinimumMinorDiameter.Allclassesarecalcu-latedandthenroundedofftothenearest0.001in.andexpressedinthreedecimalplacesforsizes0.138in.andlarger.ForClass3B,azeroisaddedtoyieldfourdecimalplaces.(2) MaximumMinorDiameter.Allcla
30、ssesarecalcu-latedbeforerounding,thenroundedforClasses1Band2Btothenearest0.001in.forsizes0.138in.andlarger.Class3Bvaluesareroundedtofourdecimalplaces.3.1.4 Metricscrewthreadsaredimensionedinmilli-meters.Thefinalvaluesofpitchdiameter,majordiame-ter,minordiameter,allowanceandthreadelementtolerancesare
31、expressedtothreedecimalplaces.3.1.5 Values containing multiple trailing zeros outto the required number of decimal places can beexpressedbydisplayingonlytwoofthembeyondthelastsignificantdigit.EXAMPLE: 20 threads per inch has a pitch equal to 0.05000000andcanbeexpressedas0.0500.3.2 ExamplesTheformula
32、sintheexamplesforinchscrewthreadsinTables2,3,4and5arebasedonthoselistedinASMEB1.1, Unified Inch Screw Threads. Tables 2 and 3 arebasedonasizethatwhenconvertedfromafractiontoa decimal will result in a number that has only fourdecimalplaces.Tables4and5arebasedonasizethatwhen converted will result in a
33、 number with infinitenumbersofdigitsafterthedecimalpoint.TheformulasintheexamplesformetricscrewthreadsinTables6,7,8and9arebasedonthoselistedinASMEB1.13M,MetricScrewThreads.Tables6and7showtheuseofthetabulatedvaluesforallowancesandtolerances(inaccordancewithISO965-1)forthecalculationofsizelimitsforsta
34、ndarddiameter/pitchcombinationslistedinbothISO261andASMEB1.13M.Theconstantvaluesdifferfromthoseusedforinchscrewthreads,inaccor-dancewiththepolicyofroundingofthisStandard,becausemetriclimitsofsizeareexpressedtoonlythreedecimalplacesratherthanfour.4 THREAD FORM CONSTANTSForthreadformdatatables,seeTabl
35、e10.Thenumberof decimal places and the manner in which they areSCREW THREADS: STANDARD PRACTICE FOR ASME B1.30-2002CALCULATING AND ROUNDING DIMENSIONSlistedshouldbeconsistent.Threadformconstantsprintedinolderthreadstandardsarebasedonafunctionofthreadheight(H)orpitch(P).Theequivalentofthecorrespondin
36、g function is also listed. There are someconstantsthatwouldrequirethesevaluesto8or7deci-malplacesbeforetheywouldroundtoequivalentval-ues.Forstandardizationthetabulatedlistingofthread3valuesbasedonafunctionofpitchhasbeenestablished,withthreadheightusedasareferenceonly.Allthreadcalculations are to be
37、performed using a function ofpitch (P), rounded to 8 decimal places for inch seriesand as designated for metric series, not a function ofthreadheight(H).Threadheightistobeusedforrefer-enceonly.ASME B1.30-2002 SCREW THREADS: STANDARD PRACTICE FORCALCULATING AND ROUNDING DIMENSIONSTable2ExampleofExter
38、nalInchScrewThreads,12-28UNEF-2AThreadSizep12-28or0.5000-28UNEF-2ACharacteristicDescriptionExampleofSizeCalculationAdditionalInformation(1)Maximumexternalmajordiameter(dmax.)dmax.pdbsces.pBasicmajordiameter(dbsc)allowance(es)dbscp0.5000Thisisthefinalvalueofthebasicmajordiameterwhichisroundedtofourde
39、cimalplaces.esp0.300(Td2forclass2A)FortheClass2Apitchdiametertolerance,seeTable2(4).esp0.300(0.003668)ThesixdecimalplacevalueforClass2Apitchdiametertolerance(Td2)isusedinthiscalculation.esp0.001100Thisfigureisroundedtofourdecimalplacestoobtainthefinalvalueofes.esp0.0011.dmax.p0.50000.0011.dmax.p0.49
40、89.(2)Minimumexternalmajordiameter(dmin.)dmin.pdmax.Td.pMaximumexternalmajordiameter(dmax.)majordiametertolerance(Td)Tdp0.0603H20906P2.Tdp0.0603H20906(0.03571429)2Allthreadcalculationsaretobeperformedusing(P)roundedto8decimalplaces.Tdp0.0603H209060.001276).Tdp0.060(0.108463).Tdp0.006508Thisfigureisr
41、oundedtofourdecimalplacestoobtainthefinalvalueofTd.Tdp0.0065.dmin.p0.49890.0065.dmin.p0.4924.4SCREW THREADS: STANDARD PRACTICE FOR ASME B1.30-2002CALCULATING AND ROUNDING DIMENSIONSTable2ExampleofExternalInchScrewThreads,12-28UNEF-2A(Contd)ThreadSizep12-28or0.5000-28UNEF-2ACharacteristicDescriptionE
42、xampleofSizeCalculationAdditionalInformation(3)Maximumexternalpitchdiameter(d2max.)d2max.pdmax.2has.pMaximumexternalmajordiameter(dmax.)twicethe2hasp0.64951905P.externalthreadaddendum(2has)2hasp0.64951905(0.03571429)Allthreadcalculationsaretobeperformedusing(P)roundedto8decimalplaces.2hasp0.023197.d
43、2max.p0.49890.023197.d2max.p0.475703Thisfigureisroundedtofourdecimalplacestoobtainthefinalvalueofd2max.d2max.p0.4757.(4)Minimumexternalpitchdiameter(d2min.)d2min.pd2max.Td2.pMaximumexternalpitchdiameter(d2max.)externalpitchdiametertolerance(Td2)Td2p0.00153H20906dbsc+0.0015H20906LE+0.0153H20906P2LE(l
44、engthofengagement)requiredinthisexample,isequalto9P.SeeASMEB1.1forLEapplicationsforotherthreadseries.Td2p0.00153H209060.5000+0.0015H209069(0.03571429)+0.0153H20906(0.03571429)2.Td2p0.00153H209060.5000+0.0015H209060.321429+0.0153H209060.001276.Td2p(0.0015)(0.793701)+(0.0015)(0.566947)+(0.015)(0.10846
45、3).Td2p0.001191+0.000850+0.001627.Td2p0.003668ThisfigureisroundedtosixdecimalplacestoobtainthefinalvalueoftheexternalpitchdiametertoleranceTd2.d2min.p0.47570.003668.d2min.p0.472032Thisfigureisroundedtofourdecimalplacestoobtainthefinalvalueofd2min.d2min.p0.4720.5ASME B1.30-2002 SCREW THREADS: STANDAR
46、D PRACTICE FORCALCULATING AND ROUNDING DIMENSIONSTable2ExampleofExternalInchScrewThreads,12-28UNEF-2A(Contd)ThreadSizep12-28or0.5000-28UNEF-2ACharacteristicDescriptionExampleofSizeCalculationAdditionalInformation(5)MaximumexternalUNRminordiameter(d3max.)d3max.pdmax.2hs.pMaximumexternalmajordiameter(
47、dmax.)doubleheight2hsp1.19078493P.ofexternalUNRthread(2hs)2hsp1.19078493(0.03571429)Allthreadcalculationsaretobeperformedusing(P)roundedto8decimalplaces.2hsp0.042528.d3max.p0.49890.042528.d3max.p0.456372Thisfigureisroundedtofourdecimalplacestoobtainthefinalvalueofd3max.d3max.p0.4564.(6)Maximumextern
48、alUNminordiameter(d1max.)d1max.pdmax.2hs.pMaximumexternalmajordiameter(dmax.)doubleheight2hsp1.08253175PForUNthreads,2hsp2hnofexternalUNthread(2hs)2hsp1.08253175(0.03571429)Allthreadcalculationsaretobeperformedusing(P)roundedto8decimalplaces.2hsp0.038662.d1max.p0.49890.038662.d1max.p0.460238Thisfigu
49、reisroundedtofourdecimalplacestoobtainthefinalvalueofd1max.d1max.p0.4602.GENERALNOTES:(a)Alldimensionsexpressedininchesforcalculationsinthistable.(b)Pp1/np1/28p0.03571429.6SCREW THREADS: STANDARD PRACTICE FOR ASME B1.30-2002CALCULATING AND ROUNDING DIMENSIONSTable3ExampleofInternalInchScrewThreads,12-28UNEF-2BThreadSizep12-28or0.5000-28UNEF-2BCharacteristicDescriptionExampleofSizeCalculationAdditionalInformation(1)Minimuminternalminordiameter(D1min.)D1min.pDbsc2hn.pBasicmajordiameter(Dbsc)doubleheightofinternal2hnp1.08253175P.thread(2hn)2hnp1.08253175(0.0357
