3-4M_R2002_E1986.pdf

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 D Hexagon Socket Button Head Cap Screws(Metric Series)Government Key Words:Screw,Cap,Hexagon Socket Button Head-Metric SPONSORED AND PUBLfSHED BY T H E A M E R I C A N S O C I E T Y O F M E C H A N I C A L E N G I N E E R S United Engineering Center 345 East 47th Street New York,N.Y.1 001 7 Copyrighted material licensed to Stanford University by Thomson Scientific(),downloaded on Oct-05-2010 by Stanford University User.No further reproduction or distribution is permitted.Uncontrolled when printed.REAFFIRMED 2002FOR CURRENT COMMITTEE PERSONNELPLEASE E-MAIL CSasme.orgDate of Issuance:February 15,1986 This Standard will be revised when the Society approves the issuance of a new edition.There will be no addenda or written interpretations of the requirements of this Standard issued to this Edition.This code or standard was developed under procedures accredited as meeting the criteria for American National Standards.The Consensus Committee that approved the code or standard was balanced to assure that individuals from competent and concerned interests have had an oppor-tunity to participate.The proposed code or standard was made available for public review and comment which provides an opportunity for additional public input from industry,academia,reg-ulatory agencies,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 in connection with any items mentioned in this document,and does not undertake to insure anyone utilizing a standard against liability for infringement of any applicable Letters Patent,nor assume any such liability.Users of a code or standard are expressly advised that determination of the validity of any such patent rights,and the risk of infringement of such rights,is entirely their own responsibility.Participation by federal agency representative(s1 o r person(s1 affiliated with industry is not to be interpreted as government or industry endorsement of this code or standard.ASME accepts responsibility for only those interpretations issued in accordance with governing ASME procedures and policies which preclude the issuance of interpretations by individual vol-unteers.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.Copyright 1987 by THE AMERICAN SOCIETY OF MECHANICAL ENGINEERS All Rights Reserved Printed in U.S.A.Copyrighted material licensed to Stanford University by Thomson Scientific(),downloaded on Oct-05-2010 by Stanford University User.No further reproduction or distribution is permitted.Uncontrolled when printed.FOREWORD(This Foreword is not part of ASME/ANSI B18.3.4M-1986.)American National Standards Committee B18 for the standardization of bolts,screws,nuts,rivets,and similar fasteners was organized in March 1922,as Sectional Committee B18 under the aegis of the American Engineering Standards Committee(later the American Standards Association,then the United States of America Standards Institute and,as of October 6,1969,the American National Standards Institute,Inc.),with the Society of Automotive Engineers and the American Society of Mechanical Engineers as joint sponsors.Subcommittee No.9 was established in April of 1929 to undertake develoment and oversee maintenance of standards covering Socket Head Cap Screws and Set Screws.In line with a general realignment of the subcommittee structure on April 1,1966,Subcommittee 9 was redesignated Subcommittee 3.Over the intervening years this activity has produced several versions of American National Standards covering inch series socket cap,shoulder,and set screws bearing the B18.3 designation.At the December 4,1974 meeting of American National Standards Committee B 18,Sub-committee 3 was assigned the task of preparing for metric series socket screw products par-alleling that contained in the latest ANSI B18.3 document.The subcommittee was also in-structed to continue coordination with the International Standards Organization,IS0 Technical Committee 2 and Working Group 3 under that activity,and to the extent possible keep the proposals for metric standards under development in conformance with agreements reached therein.Subsequent meetings of Subcommittee 3 held in February 1975 and January 1976 resulted in general agreement on the following basic principles to be considered in developing the metric version of the standard:(a)to assure consumers continuity of performance integrity consistent with inch socket screw products,the metric standards should maintain the same quality levels as their inch counterparts;(b)to facilitate and expedite the processing,acceptance,and adoption of the metric ver-sions,proposals for the various product categories should be prepared as separate and complete product standards;(c)to promote understanding and