-2-2_R2005_E1987.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 Square and Hex Nuts(Inch Series)ASMEIANSI B 18.2.2-1 987 REAFFIRMED 1993 FOR CURRENT COMMITEE PERSONNEL PLEASE SEE ASME MANUAL AS-1 1 r REAFFIRMED 1999-FOR CURRENT COMMllTEE PERSONNEL PLEASE SEE ASME MANUAL AS-1 1 SPONSORED AND PUBLISHED 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 Copyright 1987 by the American Society of Mechanical Engineers.No reproduction may be made of this material without written consent of ASME.cCopyrighted 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 2005FOR CURRENT COMMITTEE PERSONNELPLEASE E-MAIL CSasme.orgDate of Issuance:August 15,1987 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 opportunity to participate.The proposed code or standard was made available for pub!ic review and comment which provides an opportunity for additional public input from industry,academia,regulatory agencies,and the public-at-large.PSME does not approve,rate,or endorse any item,construction,proprietary device,or actlivity.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 or person(s)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 volunteers.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 0 1987 by THE AMERICAN SOCIETY OF MECHANICAL ENGINEERS All Rights Reserved Printed in U.S.A.Copyright 1987 by the American Society of Mechanical Engineers.No reproduction may be made of this material without written consent of ASME.cCopyrighted 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 818.2.2-1987.)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 Auto-motive Engineers and the American Society of Mechanical Engineers as joint sponsors.Subcommittee 2 was subsequently established and charged with the responsibility for tech-nical content of standards covering wrench head bolts and nuts.Subcommittee 2,after appraisal of the requirements of industry,developed a proposed standard series of bolt head and nut dimensions.This proposal was finally approved and designated a Tentative American Standard in February 1927.A first revision of the document was designated as an American Standard in March 1933 and was followed by a second revision which was granted approval as an American Stan-dard in January 1941.Following reorganization of the B18 Committee in 1947,Subcommittee 2 was asked to expand the standard on head proportions into a complete product standard.A proposal covering square and hexagon head bolts and nuts,hexagon head cap screws,and automo-tive hexagon head bolts was prepared and submitted to the B18 Committee in April 1950.While this draft was under consideration,the B18 Committee received a proposal from the British Standards Institution for unification of dimensions on products incorporating uni-fied screw threads.The Committee welcomed the opportunity of discussing the proposals and an American-British-Canadian Conference was held in New York on June 1 and 2,1950.It was a