1、ASME B18.21.2M-1999(Revision of ASME B18.21.2M-1994)LOCK WASHERS(METRIC SERIES) A N A M E R I C A N N A T I O N A L S T A N D A R DB18.21.2M-1999 5/10/00 2:34 PM Page 1Intentionally left blank A N A M E R I C A N N A T I O N A L S T A N D A R DLOCK WASHERS(METRIC SERIES)ASME B18.21.2M-1999(Revision
2、of ASME B18.21.2M-1994)B18.21.2M-1999 5/10/00 2:34 PM Page 3p. 1 07-12-01 12:02:35 Unit: UCP Textfile: B18212$cpe p. 1Date of Issuance: January 31, 2000This Standard will be revised when the Society approves the issuance ofa new edition. There will be no addenda or written interpretations of therequ
3、irements 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 forAmerican National Standards. The Standards Committee that approved the code or
4、standardwas balanced to assure that individuals from competent and concerned interests have had anopportunity to participate. The proposed code or standard was made available for public reviewand comment that provides an opportunity for additional public input from industry, academia,regulatory agen
5、cies, 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 inconnection with any items mentioned in this document, and does not undertake
6、 to insure anyoneutilizing a standard against liability for infringement of any applicable letters patent, nor assumesany such liability. Users of a code or standard are expressly advised that determination of thevalidity of any such patent rights, and the risk of the infringement of such rights, is
7、 entirely theirown responsibility.Participation by federal agency representative(s) or person(s) affiliated with industry is not tobe interpreted as government or industry endorsement of this code or standard.ASME accepts responsibility for only those interpretations of this document issued inaccord
8、ance with the established ASME procedures and policies, which precludes the issuanceof 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 Me
9、chanical EngineersThree Park Avenue, New York, NY 10016-5990Copyright 2000 byTHE AMERICAN SOCIETY OF MECHANICAL ENGINEERSAll Rights ReservedPrinted in U.S.A.p. 3 12-23-99 08:19:25 Unit: ufw Textfile: b18212$fw p. 3FOREWORDAmerican National Standards Committee B27 for the standardization of plain and
10、 lockwashers was organized in March 1926 as Sectional Committee B27 under the aegis of theAmerican Standards Association (later the United States of America Standards Institute and,as of October 6, 1969, the American National Standards Institute, Inc.), with the Societyof Automotive Engineers and th
11、e American Society of Mechanical Engineers as jointsponsors. Since 1950, this Committee has been designated responsibility for standardizationof washers and machine rings.In May of 1928, the B27 Committee established two subcommittees to carry on developmentwork: Subcommittee 11on plain washers and
12、Subcommittee 21on lock washers. A tentativestandard for helical spring lock washers circulated for industry comment in November 1931failed to achieve acceptance and Committee activity became dormant for some years.In 1940, the B27 Committee was reorganized and Subcommittee 2 proceeded to draft aprop
13、osal covering three series of helical spring lock washers, designated light, medium, andheavy. In 1943, this proposal was amended to include the extra-heavy series washers and,following approval by the B27 Committee and sponsor organizations, was accepted as anAmerican Standard under the designation
14、 ASA B27.1-1944.During the ensuing years, minor refinements to the hardness requirements and methodsof test were considered, and in December 1948, the B27 Committee accepted, in principle,expansion of the standard to cover helical spring lock washers made from materials otherthan carbon steel and in
15、clusion of specifications for tooth lock washers, and both helicalspring and tooth lock washer machine screw assemblies. A draft proposal incorporatingrequirements applicable to corrosion resistant steel, phosphor bronze, silicon bronze, aluminum-zinc alloy, and K-monel helical spring lock washers a
16、nd the other new products wascompleted by Subcommittee 2 in September 1949. Subsequent to approval by the B27Committee and sponsors, this proposal was forwarded to the American Standards Associationand declared an American Standard on May 22, 1950.During the years 1951 through 1958, Subcommittee 2 h
17、eld five meetings, at which itwas agreed to extend the light and heavy series helical spring lock washers to include sizes158in. through 3 in., establish tolerances on the nominal thickness of helical spring lockwashers, and recognize hardened screw and lock washer assemblies. A format draft datedJu
18、ne 1957 was approved by the letter ballot of the B27 Committee and the sponsororganizations and submitted to the American Standards Association for designation as anAmerican Standard. This was granted on November 3, 1958.Throughout the period from 1959 through 1961, a number of changes were recommen
19、dedby the Helical Washer Institute, which had undertaken a program to refine the helical springlock washers to meet more exacting demands of consumer industries. Also, at a meetingheld on November 28, 1961, the B27 Committee recognized the desirablity of publishingthe screw and washer assemblies as
20、a separate document under the jurisdiction of the B18Committee, but subject to joint approval by the B27 Committee and affected subcommitteesthereof. Subsequently, a draft proposal deleting the coverage on screw and washer assemblies1As of April 1, 1966, Subcommittee 1 was redesignated Subcommittee
21、2 on plain washers, and Subcommittee2 was redesignated Subcommittee 1 on lock washers.iiip. 4 12-23-99 08:19:25 Unit: ufw Textfile: b18212$fw p. 4and incorporating revisions to the helical spring lock washers was prepared. The latterincluded changing designation of medium series to regular series an
22、d extra-heavy series toextra-duty series, and the addition of the hi-collar series for use with socket head capscrews. Following acceptance by the subcommittee, the proposal was letter balloted to theB27 Committee on November 18, 1963, then approved by the sponsors and the AmericanStandards Associat
23、ion and officially granted recognition as an American Standard onSeptember 20, 1965.Continued studies conducted by the Helical Washer Institute resulted in this groupsubmitting further recommendations for changes to the standard at a meeting of AmericanNational Standards Committee B27 in October 196
24、9. Subcommittee 1 then undertookpreparation of a proposal dated May 1970, incorporating changes to helical spring lockwashers. These consisted of deleting coverage for the light series and Type 420 corrosionresistant steels, adding control on section corner radius, adjusting inside diameters, andrel
25、egating the heavy series to “Not Recommended for New Applications” status. Otherminor corrections to dimensional data and extensive editorial refinements were also included.This draft was approved by letter ballot of Standards Committee B27, conducted on August11, 1970. Subsequent to the inclusion o
26、f additional editorial refinements, the proposal wasfound acceptable by the sponsor organizations and submitted to the American NationalStandards Institute for designation as an American National Standard. After approval ofthis revision by American National Standards Committee B27, the washer activi
27、ty wastransferred to American National Standards Committee B18. Subcommittee 1 of B27 wasredesignated as Subcommittee 21 of Standards Committee B18.At the December 1986 American National Standards B18 main meeting, a request wasmade to have Subcommittee 21 draft an American National Standard for met
28、ric lock washers.On May 26, 1987, the first draft of the requested standard was completed. This draft wasbased on the inch series standard, which was being reviewed and revised at the time bySubcommittee 21. Dimensional data and types of lock washers to be included in the tableswere gathered from in
29、dustry standards. Both standards were then updated as requiredduring the May and December 1987 subcommittee meetings. At the December 1987meeting, a motion to ballot the standard was made, and by the December 1988 meeting,all ballot comments were reviewed and editorial changes were made. At the May
30、1989meeting, the completed draft dated May 6, 1989 was submitted for publication.On December 9, 1992, a proposal to revise this Standard was made. This Standard hasnot been used with the dimensions in Table 2 or with the product listed in Table 3. Thisrevision changes the dimensions in Table 2 to re
31、flect active part dimensions and replacesTable 3, Metric Socket Head Helical Spring Lock Washers, with a new Table 3 for MetricHeavy Helical Spring Lock Washers. In addition, the trapezoid dimensions were replacedwith the formula used in prior standards; several materials and hardness values were ad
32、ded;paragraphs covering lot size, inspection and quality assurance requirements, and inspectioncharacteristics were added, and editorial changes were made. The proposal was sent outfor balloting, and at the December 7, 1993 meeting, comments were reviewed and actedupon as needed.On December 4, 1995,
33、 a proposal to clarify items in this Standard was made. Forhelical spring lock washers, the changes included, adding clearance to the washer insidediameter needing heavier coatings such as mechanically galvanizing, moving decarb measuringrequirement into proper location, and correcting illustrations
34、 above tables. For the toothlock washer, the changes include clarifying the wording in the measurement of the toothprojection from side to side, and removing the need for twist testing. In addition, theStandard was revised to conform with the standard formatting for B18 documents.This Standard was a
35、pproved as an American National Standard on November 3, 1999.ivp. 5 12-23-99 08:20:30 Unit: ucr Textfile: b18212$cr p. 5ASME STANDARDS COMMITTEE B18Standardization of Bolts, Nuts, Rivets, Screws, Washers,and Similar Fasteners(The following is the roster of the Committee at the time of approval of th
36、is Standard.)OFFICERSD. A. Clever, ChairR. D. Strong, Vice ChairS. W. Vass, Vice ChairR. L. Crane, SecretaryCOMMITTEE PERSONNELJ. Altman, Rotor Clip Co.J. B. Belford, Lawson Products, Inc.J. A. Buda, SPS TechnologiesR. M. Byrne, Trade Association ManagementD. A. Clever, Deere and Co.A. P. Cockman, F
37、ord Motor Co.T. Collier, Cam-Tech Industries, Inc.R. L. Crane, The American Society of Mechanical EngineersA. C. Dicola, Wrought Washer Co.W. D. Downing, Emhart Heli-CoilB. A. Dusina, Federal Screw WorksD. S. George, Ford Motor Co.J. Greensdale, Greensdale and Co.B. Hasiuk, Defense Industrial Supply
38、 CenterA. Herskovitz, ConsultantA. C. Hood, ConsultantJ. Hubbard, Rockford Fastener, Inc.F. W. Kern, The Society of Automotive Engineers, Inc.J. F. Koehl, Spirol International Corp.W. H. Kopke, ITW ShakeproofJ. G. Langenstein, ConsultantM. Levinson, ITW ShakeproofL. L. Lord, Caterpillar, Inc.A. D. M
39、cCrindle, Genfast Manufacturing Co.K. E. McCullough, Spring House EstatesM. D. Prasad, General Motors Corp.W. Schevey, BGM Fastener Co., Inc.R. D. Strong, General Motors Corp.J. F. Sullivan, National Fasteners Distributors AssociationS. W. Vass, Industrial Fasteners InstituteC. B. Wackrow, MNP Corp.
40、R. G. Weber, Fairfield UniversityW. K. Wilcox, Navsea 03P6C. J. Wilson, Industrial Fasteners InstituteR. B. Wright, Hand Tools InstituteJ. G. Zeratsky, Tubular and Machine Institutevp. 6 12-23-99 08:20:30 Unit: ucr Textfile: b18212$cr p. 6SUBCOMMITTEE 21 LOCK WASHERSW. H. Kopke, Chair, ITW Shakeproo
41、fD. A. Clever, Deere and Co.A. Herskovitz, ConsultantM. Levinson, ITW ShakeproofL. C. Schroeder, Kansas Dept. of Transportation Materials and Research CenterJ. F. Sullivan, National Fasteners Distribution Associationvip. 7 12-23-99 08:20:45 Unit: ucc Textfile: b18212corr p. 7CORRESPONDENCE WITH THE
42、B18 COMMITTEEGeneral. ASME Standards are developed and maintained with the intent to represent theconsensus of concerned interests. As such, users of this Standard may interact with theCommittee by requesting interpretations, proposing revisions, and attending committeemeetings. Correspondence shoul
43、d be addressed to:Secretary, B18 Main CommitteeThe American Society of Mechanical EngineersThree Park AvenueNew York, NY 10016-5990Proposing Revisions. Revisions are made periodically to the Standard to incorporatechanges that appear necessary or desirable, as demonstrated by the experience gained f
44、romthe application of the Standard. Approved revisions will be published periodically.The Committee welcomes proposals for revisions to this Standard. Such proposals shouldbe as specific as possible, citing the paragraph number(s), the proposed wording, and adetailed description of the reasons for t
45、he proposal, including any pertinent documentation.Interpretations. Upon request, the B18 Committee will render an interpretation of anyrequirement of the Standard. Interpretations can only be rendered in response to a writtenrequest sent to the Secretary of the B18 Main Committee.The request for in
46、terpretation should be clear and unambiguous. It is further recommendedthat the inquirer submit his request in the following format:Subject: Cite the applicable paragraph number(s) and the topic of the inquiry.Edition: Cite the applicable edition of the Standard for which the interpretationis being
47、requested.Question: Phrase the question as a request for an interpretation of a specificrequirement suitable for genral understanding and use, not as a requestfor an approval of a proprietary design or situation. The inquirer mayalso include plans or drawings which are necessary to explain the quest
48、ion;however, they should not contain proprietary names or information.Requests that are not in this format will be rewritten in this format by the Committeeprior to being answered, which may inadvertently change the intent of the original request.ASME procedures provide for reconsideration of any in
49、terpretation when or if additionalinformation that might affect an interpretation is available. Further, persons aggrieved byan interpretation may appeal to the cognizant ASME Committee or Subcommittee. ASMEdoes not “approve”, “certify”, “rate”, or “endorse” any item, construction, proprietary device,or activity.Attending Committee Meetings. The B18 Committee regularly holds meetings, which areopen to the public. Persons wishing to attend any meeting should contact the Secretaryof the B18 Main Committee.viiIntentionally left blank p. 9 12-15-99 10:01:05 Unit: uct Textfile: b18212$ct
