3-2M_R2003_E1979.pdf

A M E R I C A N N A T I O N A L S T A N D A R D Metric Series Hexagon Keys and Bits ANSI B18.3.2M -1979 For Socket Screw Products-REAFFIRMED 1990 FOR CURRENT COMMITTEE PERSONNEL PLEASE SEE ASME MANUAL AS-11 SECRETARIAT SOCIETY OF AUTOMOTIVE ENGINEERS THE AMERICAN SOCIETY OF MECHANICAL ENGINEERS-_-REAFFIRMED 1998 FOR CURRENT COMMITTEE PERSONNEL PLEASE SEE ASME MANUAL AS-1 1 P U B L I S H E D 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.1001 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.orgNo part of this docu.ment may be reproduced in any form,in an electronic retrieval system or otherwise,without the prior written permission of the publisher.-.:ii.,.-Date of Issuance:August 31,1979 THE AMERICAN SOCIETY OF MECHANICAL ENGINEERS Copyright 0 1979 by 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 The 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 Insti-tute,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 development and oversee mainte-nance 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 B18,Subcommittee 3 was assigned the task of preparing standards for metric series socket screw products paralleling that con-tained in the latest ANSI B18.3 document.The subcommittee was also instructed 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 con-formance 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 stan-dard:(1)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;(2)to facilitate and expedite the processing,acceptance and adoption of the metric versions,proposals for the various product categories should be prepared as separate and complete product standards;(3)to promote understanding and assimilation during the transition to metric the dimensional symbols,designations,terminology and basic formats of the metric standards should be kept similar to that used in the ANSI B18.3 document.At the November 10,1976 meeting of Subcommittee 3,it was agreed the socket screw industry docu-ment covering metric hexagon keys should be circulated for subcommittee consideration as a proposed standard.It was noted that this document included the 0.7,0.9 and 1.3 mm key sizes which were soft conversions of the 0.028,0.035 and 0.050 inch keys,respectively,required for wrenching the 1.6,2 and 2.5 mm set screws already called for in IS0 standards and that although there were differences in the tolerance structure and strength capabilities,the keys contained therein would satisfy the dimensional and mechanical requirements of the existing IS0 standard covering keys for sizes 2.5 mm and larger.Subcom-mitteee acceptance of the content ensued and the document,modified to more closely suit the ANSI format,was approved by letter ballot to American National Standards Committee B18.Following its approval by the sponsor organizations,the proposal was duly submitted to the American National Standards Institute and was granted recognition as an American National Standard on May 17,1979.iii 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 wh