1、AN AMERICAN NATIONAL STANDARD ASME B18.13-2017Revision of ASME B18.13-1996 (R2013)Screw and Washer Assemblies SEMS (Inch Series)ASME B18.13-2017Revision of ASME B18.13-1996 (R2013)Screw and WasherAssemblies SEMS(Inch Series)AN AMERICAN NATIONAL STANDARDTwo Park Avenue New York, NY 10016 USADate of I
2、ssuance: January 23, 2017This Standard will be revised when the Society approves the issuance of a new edition.ASME issues written replies to inquiries concerning interpretations of technical aspects of thisStandard. Interpretations are published on the Committee Web page and undergo.asme.org/Interp
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12、TENTSForeword ivCommittee Roster . viCorrespondence With the B18 Committee vii1 Introduction . 12 General Data 113 Data for Helical Spring Lock Washer SEMS 124 Data for Tooth Lock Washer SEMS 135 Data for Conical Spring Washer SEMS . 136 Data for Plain Washer SEMS 14Figures1 Unthreaded Length on Scr
13、ews With Machine Screw Thread DiameterPitchCombinations 112 Unthreaded Length on Tapping Screws With Spaced Thread DiameterPitchCombinations 113 Verification of Bearing Width on Helical Spring Lock Washers . 134 Enlarged Conical Spring Washer Section and Tooth Washer Dimensions 145 Conical Spring Wa
14、sher Twist Test . 15Tables1 Dimensions of Helical Spring Lock Washers for Socket Head Cap Screw SEMS . 22 Dimensions of Helical Spring Lock Washers for SEMS With Machine andTapping Screws Having Machine Screw Thread DiameterPitchCombinations 33 Dimensions of Helical Spring Lock Washers for SEMS With
15、 Screws HavingType B Tapping Screw Thread DiameterPitch Combinations 44 Dimensions of Internal Tooth Lock Washers for SEMS . 55 Dimensions of External Tooth Lock Washers for SEMS . 66 Dimensions of Conical Spring Washers for SEMS 77 Dimensions of Plain Washers for SEMS . 9Nonmandatory AppendixA Rela
16、tive Proportions of Screw Heads and Plain or Conical Spring Washers . 17iiiFOREWORDAmerican National Standards Committee B27 for the standardization of plain and lock washerswas organized in March 1926 as Sectional Committee B27 under the aegis of the AmericanStandardsAssociation(laterthe UnitedStat
17、esofAmericaStandardsInstitute and,asofOctober6,1969, the American National Standards Institute, Inc.) with the Society of Automotive Engineersand the American Society of Mechanical Engineers as joint sponsors. (Since 1950, this Committeehas also been assigned responsibility for standardization of wa
18、shers and machine rings.) TheCommittee was reorganized in May 1928, at which time two subcommittees were established tocarry on development work: Subcommittee 11on plain washers and Subcommittee 2 on lockwashers.In 1940 the B27 Committee was reactivated and Subcommittee 2 proceeded to draft a propos
19、alcovering helical spring lock washers. It was further amended in 1943 and, following approvalby the B27 Committee and sponsor organizations, accepted as an American Standard under thedesignation ASA B27.1-1994.A draft proposal completed by Subcommittee 2 in September 1949 incorporated requirementsa
20、pplicabletohelicalspringlockwashersmadefrommaterialsotherthancarbonsteelandincludedspecifications for tooth lock washers, both helical spring and tooth lock washers, and machinescrew assemblies. Subsequent to approval by the B27 Committee and sponsors, this proposalwas forwarded to the American Stan
21、dards Association and declared an American Standard onMay 22, 1950.During the years 1951 through 1956, Subcommittee 2 considered numerous refinements to thecoverage for helical spring lock washers and heat treated machine screw and lock washer assem-blies. A formal draft dated June 1957 was approved
22、 by letter ballot of the B27 Committee andthe sponsor organizations and submitted to the American Standards Association for designationas an American Standard. This was granted on November 3, 1958.In 1961 a study group comprised of members of the B18 and B27 Committees recommendedthat the screw and
23、washer assemblies, commonly known as SEMS, be published as a separatedocument under the jurisdiction of the B18 Committee, but subject to approval of both SectionalCommittees and the affected subcommittees thereof. This recommendation was accepted by theB27 and B18 Committees, respectively, on the 2
24、8th and 30th of November 1961. Subcommittee 272of Committee B18 was subsequently appointed.At the initial meeting of Subcommittee 27 on February 1, 1962 a proposal was submittedconsisting of pertinent data for lock washer SEMS, extracted from ASA B27.1-1958 and for plainwasher SEMS proposed for incl
25、usion in ASA B27.2, plus information gleaned fromSAE Standard J773, Conical Spring Washers. It was agreed that the proposal should be extendedto include tapping screw SEMS. Consequently, additional meetings of the subcommittee wereheldatwhichnewdraftsincorporatingdatafortheseproductswerereviewedandf
26、urtherchangesand corrections were recommended. On February 15, 1963, a formal proposal was circulated forcomment to Subcommittees 3, 9, and 27 of the B18 Committee, and Subcommittees 1 and 2 ofthe B27 Committee. On November 15, 1963, a revised draft incorporating resolutions to thecomments received
27、and additional refinements was letter balloted to Sectional Committees B18and B27. The resulting comments and disapprovals were resolved at a meeting of SectionalCommittee B18 on June 4, 1964, and by circulation of the recommended dispositions to Sectional1As of April 1, 1966, Subcommittee 1 was red
28、esignated Subcommittee 2 on plain washers; Subcommittee 2 wasredesignated Subcommittee 1 on lock washers under American National Standards Committee 27. As ofMarch 16, 1972, Subcommittees 1 and 2 became Subcommittees 22 and 21, respectively, of American NationalStandards Committee B18.2As of April 1
29、, 1966, Subcommittee 3 was redesignated Subcommittee 6, Subcommittee 9 was redesignatedSubcommittee 3, and Subcommitteee 27 was redesignated Subcommittee 13 of American National StandardsCommittee B18.ivCommittee B27 on February 12, 1965. Subsequent to approval by the sponsor organizationsand the Am
30、erican Standards Association, the document was formally designated an AmericanStandard, ASA B18.13-1965, on September 29, 1965.Over the next 18 years attempts were made to update and refine the document. However, duetoextendedvacanciesinthechairmanshipandcontinualshiftsinmembershipofSubcommittee13,n
31、one of these efforts proved successful and the standard was reaffirmed for three review periods.At the December 5, 1984, meeting of Subcommittee 13, it was agreed the standard should berevised to incorporate those changes necessary to bring it into agreement with the latest versionsof the referenced
32、 B18 document covering the screw and washer components and for possibleadditional refinements. Recommendations for changes were reviewed and discussed further ata meeting held on May 18, 1985, and task groups were established to prepare detailed proposalsrelative to specific product lines. A propose
33、d revision was drafted that relegated the coveragefor round and truss head SEMS and Type A and Type C tapping screw SEMS to appendicesunder “Not recommended for new design” status. The revision included dimensional coverageforsmallersizeswhereapplicable,changestothehelicalspringlockwashersectionsand
34、hardness,plus other technical and editorial updating previously accepted. This proposal was reviewed atthe December 3, 1985, meeting of Subcommittee 13. Numerous editorial refinements were consid-ered and adopted.AformalproposaldatedFebruary1986wascirculatedtoSubcommittees3,6,13,21,and22oftheB18 Com
35、mittee. A revised proposal incorporating resolutions to the comments received wasgiven letter ballot approval by Standards Committee B18 in March 1987. Following its acceptanceby ASME and the American National Standards Institute, this revision was granted recognitionas an American National Standard
36、 on January 12, 1996.At the 2014 Fall meeting of Subcommittee 13 a vote was taken and approved to revise theStandard to incorporate the new material regarding SEMS manufacturing that was introducedin the recent revision of ASME B18.13.1M and to update the format to be consistent with theother recent
37、ly revised B18 standards.The scope of the Standard was revised to more clearly reflect what is covered by the Standardand the previously included reference standards were moved out of the scope and into a separateReference Standards sections as in all other B18 standards.In particular, information w
38、as added to this Standard to more thoroughly explain that thereare two distinctly differentmeans of manufacturing SEMS products dependingon the characteris-tics of the washer and screw being combined during manufacturing. One method is to assemblescrews and washers and heat treat them as a unit afte
39、r assembly and the other method is to heattreat the washer and screw separately and then assemble them together.The referenced quality section was updated to remove the previous section listing specificfastenercharacteristicsandsamplinglevelsandtosimplyrefertotherequirementsinASMEB18.18as is now don
40、e in all B18 standards.This revision was approved as an American National Standard on January 3, 2017.Suggestions for the improvement of this Standard are welcome. They should be addressed tothe Secretary, B18 Standards Committee, The American Society of Mechanical Engineers,Two Park Avenue, New Yor
41、k, NY 10016-5990.vASME B18 COMMITTEEStandardization of Bolts, Nuts, Rivets, Screws,Washers, and Similar Fasteners(The following is the roster of the Committee at the time of approval of this Standard.)STANDARDS COMMITTEE OFFICERSF. J. Perry, ChairD. S. George, Vice ChairR. D. Strong, Vice ChairC. J.
42、 Gomez, SecretarySTANDARDS COMMITTEE PERSONNELT. Anderson, Bay BoltL. Borowski, Greenslade however, they should not contain proprietary names orinformation.viiRequests that are not in the format described above may be rewritten in the appropriate formatby the Committee prior to being answered, which
43、 may inadvertently change the intent of theoriginal request.ASME procedures provide for reconsideration of any interpretation when or if additionalinformation that might affect an interpretation is available. Further, persons aggrieved by aninterpretation may appeal to the cognizant ASME Committee o
44、r Subcommittee. ASME does not“approve,” “certify,” “rate,” or “endorse” any item, construction, proprietary device, or activity.Attending Committee Meetings. The B18 Standards Committee regularly holds meetingsand/or telephone conferences that are open to the public. Persons wishing to attend any me
45、etingand/ortelephoneconferenceshouldcontacttheSecretaryoftheB18StandardsCommittee.FutureCommittee meeting dates and locations can be found on the Committee Page atgo.asme.org/B18committee.viiiASME B18.13-2017SCREW AND WASHER ASSEMBLIES SEMS (INCH SERIES)1 INTRODUCTION1.1 ScopeThis Standard covers ge
46、neral and dimensional datapertinent to the various types of screw and captivewasher assemblies, otherwise known as SEMS. SEMSproducts may include screws, tapping screws, or boltsin sizes No. 0 through12in. diameters in various gradesand materials. The word SEMS is recognized in theUnited States as a
47、 generic term applicable to screw andwasher assemblies. Also included in this Standard isNonmandatory Appendix A illustrating the relativeproportions of plain and conical washer SEMS.NOTE: The word lock, which appears in the names of productsin this Standard, is a generic term historically associate
48、d with theiridentification and is not intended to imply an indefinite fixity inattachments where the fasteners are used.1.2 Use and ApplicationThe SEMS covered by this Standard are general pur-pose fasteners intended for mass production and otherassembly operations where speed and convenience arepar
49、amount factors. Further attributes of the variouswashers, recognized herein, are given in detail for eachtype of SEMS. Products having washers of styles andshapes not shown in this Standard may be consideredSEMS; however, these products must be covered by thepurchasers drawing, standard, or the suppliersstandards.1.3 Types of SEMSIncluded in this Standard are SEMS comprised of thefollowing types of screws and washers:(a) Helical Spring Lock Washers(1) socket head cap screws (see Table 1)(2) hex cap screws (see Table 2)(3) machine screws (see Tables 2 and 3)(4) tapping sc
