1、The American Society ofMechanical EngineersANA ME RIC A N N A T IO N A L S T A N DA R DSOCKET CAP SHOULDERAND SET SCREWSHEX AND SPLI哑EYSNCH SERIESASME B18.3-1998(Revision of ASME/ANSI B18.3-1986)Date of Issuance:July 22.1998This Standard will be revised when the Society approves the issuance ofa new
2、 edition.There will be no addenda or written interpretations of therequirements 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
3、 National Standards.The Standards Committee that approved the codeor 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
4、 for additional public input from industry.academia.regulatory agencies,and the public-at-large.ASME does not approve,rate,or endorseany 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 i
5、tems mentioned in this document,and does not undertake 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,
6、and the risk of infringement of such rights,is 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 inte
7、rpretations issued in accordance with governingASME procedures and policies which precludes the issuance of interpretations by individualvolunteers.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 publis
8、herThe American Society of Mechanical EngineersThree Park Avenue,New York,NY 10016-5990Copyright 1998 byTHE AMERICAN SOCIETY OF MECHANICAL ENGINEERSAll Rights ReservedPrinted in U.S.A.FOREWORD(This Foreword is not part of ASME B18.3-1998.)American National Standards Committee B18 for the standardiza
9、tion of bolts,screws.Dnuts,rivets,and similar fasteners was organized in March 1922 as Sectional CommitteeB18 under the aegis of the American Engineering Standards Committee(later the AmericanStandards Association,then the United States of America Standards Institute and,as ofOctober 6,1969,the Amer
10、ican National Standards Institute)with the Society of AutomotiveEngineers and the American Society of Mechanical Engineers as joint sponsors.Subcommittee No.9 on Socket Head Cap and Set Screws was organized in April 1929and completed its first report in November 1931.Seven successive drafts were iss
11、ued duringwhich the content of the proposal was considerably extended and refined,and in March1933 copies were distributed to industry for criticism and comment.The suggestions receivedwere carefully reviewed,and in April 1935 the proposal was presented to the members ofSectional Committee B18 for l
12、etter ballot vote.Following the acceptance by the two sponsororganizations,it was designated an American Standard(ASA B18.3)in February 1936 bythe American Standards Association.For the purpose of keeping the work of the Subcommittee in line with the developmentsin industry,the Committee prepared a
13、supplement to the standard in the form of a tablecovering the dimensions of hexagonal and fluted socket head shoulder screws(stripper bolts)optional,which received approval of the American Standards Association in April 1944and was designated ASA B18.3a.In March 1945,the Subcommittee submitted certa
14、in fundamental changes and additionsto the standard,and the Sectional Committee recommended issuance of a completely revisedstandard.Following approval of the Sectional Committee,the revised document was approvedby the sponsor organizations and the American Standards Association and designated anAme
15、rican Standard in April 1947.In accordance with ASA procedure,a review of the standard was undertaken in 1950and certain additional changes were recommended by the Subcommittee.Cap screw sizesNo.0 and 1 and set screw sizes No.0,1,2.3.and 4 were added to satisfy increasingdemand from various industri
16、es.Material,hardness,and thread fit were included to providea more complete standard.A draft dated November 1951 was distributed to industry forcriticism and comment.A further revision,dated November 1953.was presented to SectionalCommittee B18 for letter ballot vote.Following approval of the Sectio
17、nal Committee andsponsors,the proposal was submitted to the American Standards Association.It was approvedand designated an American Standard on August 26,1954.Shortly after the 1954 standard was issued,work was initiated on the development ofstandards covering flat countersunk head cap screws,butto
18、n head cap screws,and capscrews up to 4 in.in diameter.As these proposals evolved with comments received fromvarious industries,it became evident that a major revision was required,particularly inregard to insufficient bearing surface under the head on some sizes as well as increaseds of April 1.196
19、.Subcommittee9 was redesignated as Subcomminee 3.团socket sizes to permit higher set-up torque.The resulting proposed revision was presentedto Sectional Committee B18 for letter ballot vote.Following approval of the SectionalCommittee and sponsors.the proposal was submitted to the American Standards
20、Association.It was approved and designated an American Standard on December 21,1961Continued surveillance of the 1961 standard by the Subcommittee indicated by 1966 thata complete revision of the document was necessary to provide recognition of technicalimprovements in materials and manufacturing me
21、thods.Work over the next two yearsculminated in a March 1968 draft proposal incorporating revisions in the following areas:more clearly defined materials for all products:application of Unified radius root threadsto all cap screws;refinements to underhead fillets;extension of size coverage for flatc
22、ountersunk head cap screws to include in.through 1 in.diameters,and tabulation ofbody and grip lengths for sizes 0 in.through 1 in.;increased key engagements in socketset screws and implementation of minimum hexagon key engagement in short length setscrews;addition of width across comer dimensions f
23、or hexagon keys and bits;and theinclusion of appendices covering drill and counterbore sizes for socket head cap screws(1960 Series).and gages and gaging for spline sockets.Following acceptance of this draftby the Subcommittee,it was approved by letter ballot of USA Standards Committee B18and the sp
24、onsor organizations.and submitted to the United States of America StandardsInstitute.It was approved and designated a USA Standard on September 19.1969.A periodic review of the standard,undertaken by Subcommittee 3 in 1973,resulted inagreement that the document be revised to reflect clarification of
25、 the underhead fillet onsocket head cap screws,add coverage on drilled socket head cap screws,lengthen thethread undercut on socket head shoulder screws,and extend the coverage on the latter toinclude the 1 in.,1%in.and 2 in.sizes.A proposal incorporating these changes togetherwith numerous editoria
26、l corrections was prepared and,subsequent to Subcommittee acceptanceapproved by letter ballot to American National Standards Committee B18.Following approvalby the sponsor organizations,the proposal was submitted to the American National StandardsInstitute and designated an American National Standar
27、d on November 1,1976.A periodic review of the standard,undertaken by the Subcommittee in 1980,resulted inagreement that the document be revised to clarify the notes on screw point chamfers;berevised in socket tolerances for large sockets and in counterbore sizes to reflect standardtooling:and be rev
28、ised to reference the ASTM document A 574 for the appropriatemechanical and chemical requirements.A proposal containing these changes,as well asmany editorial corrections.was prepared for and balloted by letter ballot to the ASMECommittee B18.Following approval by the sponsor organization,the propos
29、al was submittedto the American National Standards Institute and designated an American National Standardon January 4,1982.A periodic review of the standard,undertaken by the Committee in 1985,resulted inagreement that the document be revised to clarify the dimensions with respect to platedproducts.
30、and to incorporate by reference the new ASTM documents for the appropriatemechanical,chemical.and testing requirements for the button head,flat countersunk head.and set screw products.A proposal containing these changes.as well as editorial comrections.was prepared and balloted by letter ballot to A
31、SME Committee B18.Following approvalby ASME,the proposal was submitted to the American National Standards Institute anddesignated an American National Standard on August 7.1986.A periodic review of this Standard was undertaken by the Committee in 1990.Basedon this review,it was determined that the d
32、ocument needed significant revisions to clarifyand update the Standard.These revisions would need to address the technical changes inmanufacturing methods and changes in the standards community.To accomplish this objective.established quality standards were recognized and integrated into the Standar
33、d.In addition.idesignated characteristics for each product and product identification were established andgaging techniques for countersunk screws were added.These changes were balloted andapproved by the ASME B18 Committee.The proposal was submitted to the AmericanNational Standards Institute and designated an American National Standard on January14,1998、D
