1983_2017.pdf

REAFFIRMED 2017AN AMERICAN NATIONAL STANDARD Gages and Gaging for Unified Inch Screw Threads ANWASME B1.Z1983(REVISION OF ANSI B1.2-1974)SPONSORED AND PUBLISHED BY THE AMERICAN SOCIETY OF MECHANICAL ENGINEERS United Engineering Center 345 East 47th Street New York,N.Y.10017 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.Date of Issuance:June 15,1984 This code or standard was developed under procedures accredited as meeting the criteria for Ameri-can 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 partici-pate.The proposed code or standard was made available for public review and comment which pro-vides an opportunity for additional public input from industn/,academia,regulatory agencies,and in 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 con-nection 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 lia-bility.Users of a code or standard are expressly advised that determination of the validity of any such patent rights,end the risk of infringement of such rights,is entirely their own responsibility.Participation by federal agency representativefs)or person(s)affiliated with industry is not to be in-terpreted as government or industry endorsement of this code or standard.ASME does not accept any responsibility for interpretations of this document made 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 1984 by THE AMERICAN SOCIETY OF MECHANICAL ENGINEERS All Rights Reserved Printed in U.S.A.FOREWORD(This Foreword is not part of American National Standard ANSVASME 61.2-l 983,Gages and Gaging for Unified Inch Screw Threads.)American National Standards Committee Bl for the Standardization of screw threads was organized in 1920 as Sectional Committee Bl under the aegis of the American Engi-neering Standards Committee(later the American National 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.In 1982,American National Standards Committee Bl was reorganized as the ASME Standards Committee Bl,and since then it has operated under the American Society of Mechanical Engineers Procedures to produce and update standards which may become ANSI Standards after final approval by the American National Standards Institute.A declaration of accord with respect to the unification of screw threads was signed on November 18,1948,by representatives of the services and industry of the United States,the United Kingdom,and Canada.The ANSI Unified Screw Thread Standard B 1.1,through the quadripartite standardization agreement(QST AC)247,Unified Threads,is subject to an international standardization agreement through the instrumentality of the American-British-Canadian-Australian Army Standardization Program,which recognizes B 1.1 as a standard for Unified Threads when it is required to effect the interchangeability of parts and equipment between the armies of the participating nations.The first American National Standard for Screw Thread Gages and Gaging was pub-lished as ASA B 1.2-194 1 to supplement the parent Standard AS A B 1.l-1935,Screw Threads for Bolts,Nuts,Machine Screws and Threaded Parts.That Standard was revised and re-published as a Unified Standard ASA Bl.l-1949 and again as ASA Bl.l-1960.The Uni-fled Gage Standard was republished as ASA B1.2-1951 and USA B1.2-1966.On February 9,1973,a meeting was held by the Department of Commerce at the Na-tional Bureau of Standards,Washington,D.C.,attended by representatives of government and industry screw thread interests.With the goal of eliminating parallel standards,those at the meeting recommended that the NBS Handbook H-28 be converted into a coordinat-ing document for government screw thread standards wherein sections of H-28 would be replaced by single page references to existing industry standards.It was further recom-mended that the chairman of American National Standards Committee B I set up a group to clearly define and establish identified levels of acceptability for screw threads.At an American National Standards Committee Bl meeting held on May 3,1973,unani-mous approval was given to the following motion:“The Bl Committee recognizing the needs of i