1、AGMA INFORMATION SHEET(This Information Sheet is NOT an AGMA Standard)AGMA904-C96AGMA 904- C96(Revision ofAGMA 904-B89)AMERICAN GEAR MANUFACTURERS ASSOCIATIONMetric UsageiiInformation Sheet For Metric UsageAGMA 904-C96CAUTION NOTICE: AGMA technical publications are subject to constant improve-ment,
2、revision, or withdrawal as dictated by experience. Any person who refers to anyAGMA Technical Publication should be sure that the publication is the latest availablefrom the Association on the subject matter.Tables or other self-supporting sections may be quoted or extracted. Credit linesshould read
3、: Extracted from AGMA 904-C96, Information Sheet For Metric Usage,with the permission of the publisher, the American Gear Manufacturers Association,1500 King Street, Suite 201, Alexandria, Virginia 22314.Approved October 28, 1996ABSTRACTThis information sheet is provided as an editorial guide when p
4、reparing AGMA standards. It describes the SIsystem of units and the multiples and sub-multiples to be used in AGMA standards. The purpose of theseguidelines is to assure uniformity of metric terms and abbreviations.This information sheet is a compilation of the AGMA and ISO editorial style manuals.P
5、ublished byAmerican Gear Manufacturers Association1500 King Street, Suite 201, Alexandria, Virginia 22314Copyright 1996 by American Gear Manufacturers AssociationNo part of this publication may be reproduced in any form, in an electronic retrieval system or otherwise, without priorwritten permission
6、 of the publisher.Printed in the United States of AmericaISBN: 1-55589-681-2AmericanGearManufacturersAssociationAGMA 904- C96iiiContentsPageForeword iv.1 Scope 1.2 SI Units 1.3 Multiples and Sub-multiples of SI Units 44 Units Outside the International System 65 Definitions of the SI Base Units and D
7、imensionless Derived Units 7.6 Preferred Dimensions and Tolerances 8.7 Conversion - Non-metric to Metric 10.8 Module System 139 Multiples for Use in AGMA Standards 1410 Gear Symbols for Use in Metric Standards 20FiguresFigure 5-1 Angular Units 8Figure 7-1 Total Variation Incurred by Rounding Off 11T
8、ablesTable 2-1 Base Units 1.Table 2-2 Dimensionless Derived Units 1.Table 2-3 Examples of SI Units Derived from Base Units 2Table 2-4 Examples of SI Derived Units With Special Names 2.Table 2-5 Examples of SI Units Derived From SI Units With Special Names 3Table3-1SIPrefixes 5.Table 4-1 Other Units
9、of Measurement Used with SI 6Table 6-1 Preferred Metric Tolerances and their Inch Equivalent 8Table 7-1 Possible Difference Due to Rounding 10.Table 7-2 Round Off Practice for Toleranced Dimensions 11.Table 7-3 Conversion of Other Units and Recommended Rounding Method 13.Table 8-1 Metric Modules 14T
10、able 9-1 Multiples and Conversion Factors for Use in AGMA Standards 15.AGMA 904- C96ivForewordThis foreword, footnotes, and appendices, if any, are provided for informational purposes only and should notbe construed as a part of American Gear Manufacturers Association Information Sheet 904-C96, Metr
11、icUsage.In 1972, the AGMA Technical Division Executive Committee (TDEC) started the formation of a committeereferred to as the Metric Study Committee. The first meeting of this Metric Study Committee was on January23, 1973. In March 1974, the AGMA Board of directors instructed its Technical Division
12、 to:D Form a standing Metric Resource and Advisory Committee.D Establish detailed procedures to effect a changeover, i.e., create a metric usage standard.The first meeting of the Metric Resource and Advisory Committee was held on November 4, 1974. A proposedAGMA Information Sheet, Guide for Use of S
13、I (Metric) Units in Gearing, AGMA 600.XX was drafted over thenext years. On September 21, 1977, the Metric Resource and Advisory Committee changed the name of theproposed standard 600.XX to AGMA Standard for Metric Usage. The standard 600.01 was issued in March1979.On September 12, 1979, the first d
14、raft of Procedural Guidelines for Metrication of AGMA Standards waswritten. This document was released on June 4, 1980 as Policy and Practice guide Number 040.17,Procedure for the Metrication of AGMA Standards.TheGuidelines for Metrication were approved by theAGMA Board on November 2, 1977.In 1988,
15、the TDEC converted this revision to an Information Sheet and assigned compliance review to AGMAHeadquarters Staff. In 1996, it was uptdated and the symbols tables 10.1 and 10.2 were removed, which canbe found in AGMA 900-F96.This Information Sheet is to be used as an editorial guide when preparing t
16、he AGMA metric standards andinformation sheets. It describes the SI system of units and the multiples and sub-multiples to be used inAGMA standards.The guidelines for metrication are as follows:(1) The intent of the process is conversion to SI units, not the revision of content.(2) The purpose of th
17、ese guidelines is to assure uniformity of metric terms and abbreviations.(3) Generally, metrication will be performed by the responsible committee. Exception will be at thediscretion of the TDEC.(4) There shall be two methods of generating metric standards, the choice of which shall be at thediscret
18、ion of the originating committee. All standards on which revision is begun after January 1, 1991 shall beprepared in accordance with one of the two following methods.(a) Standards may be developed in hard metric only.(b) Parallel standards, in which both hard conversion SI and conventional inch vers
19、ions of standards willbe available for the same purpose.(5) Metrication shall conform to AGMA 904-C96 which references ANSI/IEEE 268-1982 and ISO 1000.(6) Preparation of a hard metric document shall be approved by the TDEC prior to starting work.(7) The documents shall be reviewed for conformance to
20、 the Information Sheet concurrently withcommittee comment.This addition, AGMA 904-C96, was approved by the TDEC on October 28, 1996.Suggestions for the improvement of this information sheet will be welcome. They should be sent to theAmerican Gear Manufacturers Association, 1500 King Street, Suite 20
21、1, Alexandria, Virginia, 22314.AGMA 904- C96vPERSONNEL of the AGMA Committee for Metric Resource and AdvisoryCommittee (at the time of AGMA 600.01 development)J. M. Lange, Chairman (American Pfauter)D. Thurman, Vice Chairman (Caterpillar)ACTIVE MEMBERSM. R. Chaplin (Contour Hardening)P. M. Dean, Jr.
22、 (Honorary Member)R. Green (Eaton/Transmission Division)L. J. Smith (Invincible Gear)ASSOCIATE MEMBERSL. V. Campbell (Spar Aerospace)J. T. Cook (Power Tech International, Inc.)E. H. Diedrich (Rockwell)C. R. Firestone (Reliance Electric/Reeves)W. H. Heller (Peerless-Winsmith)T. J. Krenzer (Gleason)J.
23、 R. Kuehnel (Rockwell)T. Meyer (Harnischfeger)C. E. Overton (Overton Gear)J. R. Partridge (Lufkin Industries)A. E. Phillips (Emerson Power Transmission/Browning)G. R. Schwartz (Power Tech International, Inc.)H. A. Swierczynski (Fellows)G. Sykes (Falk)J. D. Szynkiewicz (Farrel)J. O. Tennies (Renold)H
24、. Wedler (Terry Corporation)AGMA 904- C96vi(This page has been left blank)AGMA 904-C96Metric Usage11. ScopeThiseditorialmanualdescribestheSIsystemofunitsto be used in AGMA standards. Where necessary,specialized metric dimensions, tolerances and unitsare used which are specifically suited to the gear
25、industry and may not be part of the referenceddocuments.1.1 Historical Background. The 11th ConferenceGenerale des Poids et Mesures (1960) (CGPM), byits Resolution 12, adopted the name InternationalSystemofUnits, withthe internationalabbreviationSI, for this practicalsystemofunits ofmeasurementandla
26、iddownrulesforthe prefixes,the derivedanddimensionless derived units and other matters, thusestablishing a comprehensive specification for unitsof measurement. The expressions SI Units, SI Pre-fixes and Dimensionless Derived Units as used in thisInformationSheet,areinaccordancewiththemetricpractices
27、 in ANSI/IEEE Std. 268-1982.2. SI Units2.1 Classes of Units. SI units are divided into threeclasses:(1) Base units(2) Derived units(3) Dimensionless derived units2.2BaseUnits. SIconsistsofsevenbaseunitsshownwith their symbols in Table 2-1. Refer to 5.1.1through 5.1.7 for definitions of base units.2.
28、3 Dimensionless Derived Units. DimensionlessderivedunitsareshowninTable2-2. Referto5.2.1and 5.2.2 for definitions of dimensionless derivedunits.2.4DerivedUnits. Derivedunitsareexpressedalge-braically in terms of base, or dimensionless derivedunits,orbothbymeansofthemathematicalsymbolsofmultiplicatio
29、nanddivision. Severalderivedunitshave been given special names and symbols whichmay themselves be used to express other derivedunitsinasimplerwaythanintermsofthebaseunits.Derived units may therefore be classified underthreeheadings. ExamplesofthemaregiveninTables2 - 3, 2 - 4 and 2 - 5.2.5 Mass and F
30、orceUnits. The principaldepartureof SI from the previous gravimetric form of MetricEngineering Units is the separate and distinct unitsfor mass and force. In previous Metric Systems, thekilogramwasusedasbothaforceandmassunit.Technically, units should have been labeled askilogram - force or kilogram
31、- mass but it was com-monpracticetoignoresuchlabeling,whichoftenre-sulted in confusion as to whether mass or force wasintended. The same practice was true in the non-metricinch-poundsystemwherethepoundwasalsoused as both a mass or force unit and rarely labeled.In SI, the kilogram is restricted to th
32、e unit of mass.Thenewtonistheunitofforceandshouldbeusedinplace of kilogram-force. Likewise, the newton,instead of kilogram-force, should be used in com-bination units which include force.Example:Pressure or Stress (N/m2=Pa),Energy (NSm=J),andPower(NSm/s = m2kgSs- 3=W).Table 2-1Base UnitsQuantity Sym
33、bolName ofBase SI Unitlength meter mmass kilogram kgtime second selectric current ampere Athermodynamictemperature* kelvin Kamount of substance mole molluminous intensity candela cd* Temperature is in general expressed in degreesCelsius (C). The unit degree Celsius is equal to theunit kelvin.Table 2
34、-2Dimensionless Derived UnitsQuantity SymbolName ofSI Unitplane angle radian radsolid angle steradian srAGMA 904-C96 Metric Usage2Table 2 - 3Examples of SI Units Derived from Base UnitsQuantityName of SIDerived UnitSymbolarea square meter m2volume cubic meter m3speed, velocity meter per second m/sac
35、celeration meter per second squared m/s2angular velocity radian per second rad/sangular acceleration radian per second squared rad/s2wave number 1 per meter m- 1density, mass density kilogram per cubic meter kg/m3Concentration (of amount of substance) mole per cubic meter mol/m3activity (radioactive
36、) 1 per second s- 1specific volume cubic meter per kilogram m3/kgluminance candela per square meter cd/m2Table 2 - 4Examples of SI Derived Units With Special NamesQuantity SymbolSpecialNameExpression in Termsof SI Base UnitsExpression in Termsof Other SI Unitsfrequency hertz Hz - - s- 1force newton
37、N - - mSkgSs- 2pressure pascal* Pa N/m2m- 1SkgSs- 2energy, work, quantity of heat joule J NSmm2SkgSs- 2power, radiant flux watt W J/s m2SkgSs- 3quantity of electricity,electric charge, coulomb C - - ASselectric potential, potential difference,electromotive force volt V W/A m2SkgSs- 3SA- 1capacitance
38、 farad F C/V m- 2Skg- 1Ss4SA2electric resistance ohm V/A m2SkgSs- 3SA- 2conductance siemens S A/V m- 2Skg- 1Ss3SA2magnetic flux weber Wb VSsm2SkgSs- 2SA- 1magnetic flux density tesla T Wb/m2kgSs- 2SA- 1inductance henry H Wb/A m2SkgSs- 2SA- 2luminous flux lumen lm - - cdSsrilluminance lux lx - - m- 2
39、ScdSsr* Bar was formerly used to express pressure: 1 bar = 100kPa or 105N/m2AGMA 904-C96Metric Usage3Table 2 - 5Examples of SI Units Derived From SI Units With Special NamesQuantitySymbolNameExpression in Termsof SI Base UnitsSI Unitdynamic viscosity pascal second PaSsm- 1SkgSs- 1moment of force new
40、ton meter NSmm2SkgSs- 2surface tension newton per meter N/m kgSs- 2heat flux density, irradiance watt per square meter W/m2kgSs- 3heat capacity, entropy joule per kelvin J/K m2SkgSs- 2SK- 1specific heat capacity, specific entropy joule per kilogram kelvin J/(kgSK) m2Ss- 2SK- 1specific energy joule p
41、er kilogram J/kg m2Ss- 2thermal conductivity watt per meter kelvin W/(mSK) mSkgSs- 3SK- 1energy density joule per cubic meter J/m3m- 1SkgSs- 2electric field strength volt per meter V/m mSkgSA- 1Ss- 3electric charge density coulomb per cubic meter C/m3m- 3SASselectric flux density coulomb per square
42、meter C/m2m- 2SASspermittivity farad per meter F/m m- 3Skg- 1SA2Ss- 4current density ampere per square meter A/m2- -magnetic field strength ampere per meter A/m - -permeability henry per meter H/m mSkgSA- 2Ss- 2molar energy joule per mole J/mol m2SkgSs- 2Smol- 1molar entropy, molar heat capacity jou
43、le per mole kelvin J/(molSK) m2SkgSs- 2SK- 1Smol- 1radiant intensity watt per steradian W/sr m2SkgSs- 3Ssr- 1radiance watt per square metersteradian W/m2Ssr kgSs- 3Ssr- 12.5.1 Weight. Considerable confusion exists in theuse of the term weight as quantity to mean eithergravitational force or mass. In
44、 commercial andeveryday use, the term weight nearly always meansmass;thus,whenonespeaksofapersonsweight,thequantity referred to is mass.In science andtechnology, theterm weight of abodyhasusuallymeanttheforcethatifappliedtothebodywould give it an acceleration equal to the localacceleration of free f
45、all.Because of the dual use of the term weight as both aforce and a mass, this term should be avoided intechnical practice.Toensurecompleteunderstandingweshouldusethetermsmassandforceinplaceofweight.Itshouldbeunderstoodthatwherethetermweightisused in machine specifications, etc., it has meantmass an
46、d to provide clarity in these uses for thegeneral public we should specify mass followed byweight in parenthesis and specify the value in gramsor kilograms. Example: Machine mass (weight)1 500 kilograms.2.5.2 Mass. In engineering calculations involvingstructures,vehicles,ormachinesonthesurfaceofthee
47、arth, the mass in kilograms is multiplied by 9.8 toobtain the approximate force of gravity in newtons.(The force of gravity acting on a mass of 1 kilogramvaries from about 9.77 newtons to 9.83 newtons invarious parts of the world).2.6 Rules for Writing SI Symbols.2.6.1 SI Symbols (see Table 9-1 for
48、SI computersymbols):(1) Shall be printed in roman (upright) type re-gardless of the type used in the rest of the textAGMA 904-C96 Metric Usage4(2)Shallbewritteninlower-caselettersexceptthat the first letter is written in upper case when thenameoftheunitisderivedfromapropername,andthe symbol for lite
49、r is a capital L. See Tables 2-1through 2-5. Examples: mmeter, s second, A am-pere, Wb weber(3) Shall remain unaltered in the plural(4) Shallbewrittenwithoutafinalfullstop(pe-riod) except at the end of a sentence(5) Shallbeplacedafterthecompletenumericalvalueintheexpressionforaquantity,leavingaspacebetween the numerical value and the first letter ofthe symbolExample: 32
