1981_2017.pdf

AMERICAN NATIONAL STANDARD Metric Plain Washers ANSI B18.22M-1981 Government Key Words:Washer,Flat,Plain-Metric SECRETARIAT SOCIETY OF AUTOMOTIVE ENGINEERS THE AMERICAN SOCIETY OF MECHANICAL ENGINEERS PUBLISHED B Y 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.10017 REAFFIRMED 2017Date of Issuance:December 15,1981 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 public review and comment which provides an opportunity for additional public input from industry,academia,regulatory agen-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 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(s)or perron(s1 affiliated with industry is not to be interpreted as government or industry endorsement of this code or standard.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 1981 by THE AMERICAN SOCIETY OF MECHANICAL ENGINEERS All Rights Reserved Printed in USA.FOREWORD 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,Incorporated),with the Society of Automotive Engineers and the American Society of Mechanical Engineers as joint sponsors.Subcommittee 22 was subsequently established and charged with the responsibility for technical content of standards covering flat washers.I n early 1976,the Subcommittee was directed to develop a new standard for metric general purpose flat washers.The first draft was based on work done by a 1975176 SAE“ad hoc”washer task force.The SAE objective,and subsequently the Subcommittee 22 objective,was to provide a standard compatible with metric bolt standards and to avoid deficiencies of the existing inch standard which had historically fostered specialty washers.Improvements were to include closer ID to bolt shank clearance for maximum bearing area,least number of OD incre-ments in rational proportion to ID,slightly increased thicknesses with minimum tolerance,and defined geometric form variability.IS0 general purpose flat washer standards and draft standards were carefully reviewed dur-ing the development of this Standard.However,due to differences in philosophy regarding flat washer manufacture and use,very few IS0 recommended sizes could be accommodated.This Standard was approved by letter ballot of Committee B18,with all negatives resolved at the 318 general meeting of May 20,1981.It was subsequently approved by the secretariat and submitted to the American National Standards Institute for designation as an American National Standkd.This designation was granted on September 2 1,198 1.NOTE The reprint of 5/98 incorporates corrections specified in an errata sheet issued previously (item number L0063E).Corrections are indicated by 5/98 in the margin.iii Intentionally left blank AMERICAN NATIONAL STANDARDS COMMITTEE B18 STANDARDIZATION OF BOLTS,NUTS,RIVETS,SCREWS,WASHERS,AND SIMILAR FASTENERS OFFICERS J.B.Levy,Chairman H.W.Ellison,Vice-chairman E.Schwartz.Vice-chairman R.McGinnis,Secretary COMMITTEE PERSONNEL AMERICAN CHAIN ASSOCIATION L.E.Hampel,Moiine Malleable Iron Company,St.Charles,Illinois AMERICAN HARDWARE MANUFACTURERS ASSOCIATION Donald Wanek,Wrought Washer Manufacturing Company,Milwaukee,Wisconsin AMERICAN SOCIETY OF AGRICULTURAL ENGINEERS E.R.Friesth,Coal Valley,Illinois AMERICAN SOCIETY OF MECHANICAL ENGINEERS,THE A.R.Machell,Jr.,Xerox Corporation,Rochester,New York R.I?Trowbridge,Detroit,Michigan C R.Adams,Alrernute,Newport News Shipbuilding&Dry Dock Company,K.E.McCuNough,Alternate,SPS Technologies,Jenkintown,Pennsylvania Newport News,Virginia ANTI-FRICTION BEARING MANUFACTURERS ASSOCIATION W J.Derner,FMC Corporation,Indianapolis,Indiana ENGINE MANUFACTURERS ASSOCIATION G.A.Rus,Cummins En