1、AN AMERICAN NATIONAL STANDARDASME B18.21.1-2009(Revision and consolidation of ASME B18.21.1 and ASME B18.22.1)Washers: Helical Spring-Lock, Tooth Lock, and Plain Washers (Inch Series)Intentionally left blank ASME B18.21.1-2009(Revision and consolidation of ASME B18.21.1 and ASME B18.22.1)Washers: He
2、licalSpring-Lock, ToothLock, and PlainWashers (Inch Series)AN AMERICAN NATIONAL STANDARDDate of Issuance: January 22, 2010This Standard will be revised when the Society approves the issuance of a new edition. There willbe no addenda issued to this edition.ASME issues written replies to inquiries con
3、cerning interpretations of technical aspects of thisStandard. Periodically certain actions of the ASME B18 Committee may be published as Cases. Casesand interpretations are published on the ASME Web site under the Committee Pages athttp:/cstools.asme.org as they are issued.ASME is the registered tra
4、demark 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 approved the code or standard was balanced to assure that individuals fromcompetent and concerne
5、d interests have had an opportunity to participate. The proposed code or standard was madeavailable for public review and comment that provides an opportunity for additional public input from industry, academia,regulatory agencies, and the public-at-large.ASME does not “approve,” “rate,” or “endorse
6、” 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 undertake to insure anyone utilizing a standard against liability forinfringement
7、of any applicable letters patent, nor assumes 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 representa
8、tive(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 accordance with the establishedASME procedures and policies, which precludes the
9、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 Mechanical EngineersThree Park Avenue, New York, NY 10016-5990Copyright 2010
10、byTHE AMERICAN SOCIETY OF MECHANICAL ENGINEERSAll rights reservedPrinted in U.S.A.CONTENTSForeword ivCommittee Roster viiCorrespondence With the B18 Committee . viii1 General Data Related to All Washers . 12 General Data for Helical Spring-Lock Washers . 23 General Data for Tooth-Lock Washers . 84 G
11、eneral Data for Plain Washers (Flat and Fender) . 14Figures1 Verifying Minimum Bearing Width . 72 Washer Twist Test 83 Tooth Lock Washers 8Tables1 Dimensions of Regular Helical Spring-Lock Washers 32 Dimensions of Heavy Helical Spring-Lock Washers 43 Dimensions of Extra-Duty Helical Spring-Lock Wash
12、ers . 54 Dimensions of High-Collar Helical Spring-Lock Washers 65 Decarburization Limits . 66 Dimensions of Internal Tooth-Lock Washers . 97 Dimensions of Heavy Internal Tooth-Lock Washers 108 Dimensions of External Tooth-Lock Washers 119 Dimensions of Countersunk External Tooth-Lock Washers . 1210
13、Dimensions of Internal/External Tooth-Lock Washers . 1311 Dimensions of Preferred Sizes of Type A Plain Washers . 1512 Dimensions of Type B Plain Washers 1713 Fender Washers 20iiiFOREWORDIn response to the request of the U.S. War Department the American National StandardsCommittee B27, for the stand
14、ardization of plain and lock washers was organized between August1925 and March 1926 as Sectional Committee B27 under the aegis of the American StandardsAssociation (later the American Engineering Standards, then The United States of AmericaStandards Institute, the American National Standards Instit
15、ute and in subsequent years, thecommittee came under the sole sponsorship of the American Society of Mechanical Engineers(ASME).In May 1928, the B27 Committee established two subcommittees to carry on developmentwork, Subcommittee 1 on plain washers and Subcommittee 2 on lock washers.Subcommittee 2
16、circulated a tentative standard for helical spring-lock washers for industrycomment in November 1931, but failed to achieve acceptance and committee activity was dormantfor some years. In 1940 the Subcommittee 2 project was reactivated and proceeded to draft aproposal covering three series of helica
17、l spring-lock washers designated light, medium, and heavy.In 1943 this proposal was amended to include the extra-heavy series washers and followingapproval by the B27 Committee and sponsor organizations it was accepted as an AmericanStandard under the designation ASA B27.1-1944.Subcommittee 1 submit
18、ted a proposed standard for plain washers in October 1932, after circula-tion it was revised and distributed in May 1935. This led to a third revision and was referred tothe sectional committee but did not receive the votes necessary for approval. From 1937 until1946 the Subcommittee 1 activity was
19、dormant owing in part to industry preoccupation with thewar effort and to the development of a standard for lock washers, there being some resistanceto the concurrent development of both projects.In 1946 the Subcommittee 1 project for plain washers was reactivated and in December of thatyear a new p
20、roposal for the standard was approved at a meeting of the sectional committeesubject to confirming approval by letter ballot. The proposal received an overwhelming vote ofapproval in the letter ballot and at the sectional committee meeting in December 1948 orderedits referral to the sponsor societie
21、s. Following approval by the B27 Committee and sponsororganizations it was accepted as an American Standard on August 31, 1949 under the designationASA B27.2-1949.Subcommittee2 consideredminor refinementsduringthe ensuingyears tothehardness require-ments and methods of testing for lock washers. In D
22、ecember 1948, the B27 Committee accepted,in principle, expansion of the Standard to cover helical spring-lock washers made from materialsother than carbon steel. A draft proposal incorporating requirements applicable to corrosion-resistant steel, phosphor bronze, silicon bronze, aluminum-zinc alloy,
23、 K-monel for helical spring-lock washers, the inclusion of specifications for tooth-lock washers, and machine screw assemblieswas completed in September 1949. Following approval by the B27 Committee and sponsors, thisproposal was forwarded to the American Standards Association and declared an Americ
24、anStandard on May 22, 1950.Subcommittee 1 reviewed the plain washer and revised it editorially to include notes coveringgeneral applications, material, thickness, and defects which were inadvertently omitted from the1949 original printing. A proposed revision dated June 1952, was approved by letter
25、ballot voteof the sectional committee, sponsors, and American Standards Association. Official designationas an American Standard was given March 30, 1953. Subsequent to publication of the 1953 issuecertain changes and inclusion of an additional series of washers were proposed. A proposedrevision dat
26、ed February 1956 was approved by letter ballot. Following the approval by the B27Committee and sponsors, this proposal was forwarded to the American Standards Associationand declared an American Standard on August 5, 1958.Subcommittee 2 held five meetings from 1951 through 1958 at which time members
27、 agreed toextend the light and heavy series helical spring-lock washer, to include sizes 158in. through3 in., establish tolerances on the nominal thickness of helical spring-lock washers, and recognizeivhardened screw and lock washer assemblies. A formal draft, dated June 1957, was approved byletter
28、 ballot of the B27 Committee and the sponsor organizations and submitted to the AmericanStandards Association for designation as an American Standard. This was granted on November3, 1958.Subcommittee 1 continued to refine the specifications for plain washers following issuance ofthe 1958 standard. S
29、everal meetings resulted in adjustment of the tolerances for inside and outsidediameters to conform with good commercial stamping practices and the application of the sametolerances to both Type A and Type B washers. Also, to provide better guidance for users, it wasagreed to tabulate the preferred
30、sizes of Type A washers separately. A proposed revision datedNovember 1963, was circulated for simultaneous letter ballot approval of Subcommittee 1 andthe Sectional Committee on November 18, 1963. Following acceptance by the subcommittee, theproposal was letter balloted to the B27 Committee on Febr
31、uary 12, 1965. The proposal wasapproved by the sponsor organizations and the American Standards Association and grantedformal recognition as an American Standard on September 20, 1965.From 1959 through 1961, a number of changes were recommended by the Helical WasherInstitute, which had undertaken a
32、program to refine the helical spring-lock washers to meet moreexacting demands of consumer industries. Also, at a meeting held on November 28, 1961 theB27 Committee recognized the desirability of publishing the screw and washer assemblies as aseparate document under the jurisdiction of the B18 Commi
33、ttee, but subject to joint approval bythe B27 Committee and affected subcommittees thereof. Subsequently, a draft proposal deletingthe coverage on screw and washer assemblies and incorporating revisions to the helical spring-lock washers was prepared. The latter included changing the designation of
34、medium series toregular series and extra-heavy series to extra-duty series, and the addition of the high-collarseries, for use with socket head cap screws. Following acceptance by the subcommittee, theproposal was letter balloted to the B27 Committee on November 18, 1963. The proposal wasapproved by
35、 the sponsor organizations and the American Standards Association and grantedformal recognition as an American Standard on September 20, 1965.As of April 1, 1966, Subcommittee 1 was redesignated Subcommittee 2 on plain washers, andSubcommittee 2 was redesignated Subcommittee 1 on lock washers to ali
36、gn with the standard(s)numbering.After continued studies conducted by the Helical Washer institute, the group submitted furtherrecommendations for changes at a meeting of the American National Standards Committee B27in October 1969. Subcommittee 1 then prepared a proposal in May 1970 to incorporate
37、therecommended changes to helical spring-lock washers. These changes consisted of deleting cover-age for the light series and Type 420 corrosion-resistant steels, adding control on section-cornerradius, adjusting the inside diameter, and relegating the heavy series to “Not Recommended forNew Applica
38、tions“ status. Other minor corrections to dimensional data and extensive editorialrefinements were also included. This draft was approved by letter ballot of Standards CommitteeB27 on August 11, 1970 and by the sponsor organizations and submitted to American NationalStandards Institute for designati
39、on as an American National Standard. After approval of thisrevision by the American National Standards Committee B27, the washer activities were trans-ferred to American National Standards Committee B18. This revision was approved as anAmerican National Standard on April 28, 1972.After the transfer
40、Subcommittee 1 of B27 was redesignated as Subcommittee 21 (Lock Washers)and Subcommittee 2 of B27 was redesignated as Subcommittee 22 (Plain Washers) of StandardsCommittee B18.Revisions were made to the lock washer in 1972 and at the December 1985 Subcommittee 21meeting a draft of these revisions wa
41、s reviewed by its members. Between that meeting and theDecember 1987 subcommittee meeting the Standard was reviewed, refinements completed andit was sent out for balloting. All ballot comments were reviewed, editorial changes made and atthe May 1989 meeting the revised draft was submitted for public
42、ation. Changes to the helicalspring lock washers included a graphic illustration with tables to help define the flat face afterthe allowable radii dimension was subtracted, lowering of the Rockwell hardness for carbonsteel, the addition of a table of hardness values for other materials, and a table
43、covering materials.Dimensional changes were made to the inside and outside diameters for regular, heavy, andextra-duty series14in. through 112in., and up to the 3 in. size for high-collar. The regular, heavy,vand extra duty tables were expanded to include the sizes from 112in. up to 3 in. The data f
44、or tooth-lock washers remained the same. Following approval by ASME, the document was submitted tothe American National Standards Institute, and was approved as an American National Standardon July 5, 1990.On December 9, 1992, a proposal to revise the dimensions of the inside diameter for58in. andla
45、rger helical spring-lock washers was developed to correct an excessive reduction in the tolerancefor these sizes. In addition, the trapezoid dimensions were replaced with the formula used inprior standards; several materials and hardness values were added; paragraphs covering lot size,inspection and
46、 quality assurance requirements, and inspection characteristics were added; andeditorial changes were made. The proposal was sent out for balloting, and at the December 7,1993 meeting, comments were reviewed and acted upon as needed. Following approval by ASME,the document was submitted to the Ameri
47、can National Standards Institute, and was approvedas an American National Standard on October 6, 1994.On December 4, 1995, a proposal was developed to revise and clarify several items in thisStandard. For helical spring-lock washers the changes included adding clearance to the washersinside diameter
48、 forheavier coatings such asthose mechanically galvanized, movingthe decarburi-zation measuring requirement into the proper designated heading, and correcting illustrationsabove tables. For tooth-lock washers, the changes included clarifying the wording used in themeasurement of the tooth projection
49、s on both sides, removing the need for twist testing, andchanging some thickness dimensions in Tables 6 and 8 and the notes for Table 9. In addition,this Standard was revised to conform to the standard format of B18 documents. This new editionof the Standard was approved as an American National Standard on November 2, 1999.During the ASME B18 Standards Committee meeting on November 28, 2007 a suggestion wasmade to incorporate the B18.22.1 Plain Washers into the B18.21.1 Lock Washers (Inch Series)standard. Both documents were reviewed and a determination was made that the proposal wasfe
