2001_2011.pdf

ASME B18.2.3.4M-2001Revision of ANSI/ASME B18.2.3.4M-1984(R1995)METRIC HEXFLANGE SCREWSA N A M E R I C A N N A T I O N A LS T A N D A R DASME B18.2.3.4M-2001Revision of ANSI/ASME B18.2.3.4M-1984(R1995)METRIC HEXFLANGE SCREWSA N A M E R I C A N N A T I O N A LS T A N D A R DREAFFIRMED 2011FOR CURRENT COMMITTEE PERSONNELPLEASE E-MAIL CSasme.orgIntentionally left blank AN AMERICAN NA TIONALST ANDARDMETRIC HEXFLANGE SCREWSASME B18.2.3.4M-2001Revision of ANSI/ASME B18.2.3.4M-1984(R1995)Date of Issuance:June 24,2002The next edition of this Standard is scheduled for publication in 2007.Therewill be no addenda issued to this edition.ASME issues written replies to inquiries concerning interpretations oftechnical aspects of this Standard.ASME is the registered trademark of The American Society of Mechanical Engineers.This code or standard was developed under procedures accredited as meeting the criteria forAmerican National Standards.The Standards Committee that approved the code or standardwas balanced to assure that individuals from competent and concerned interests have had anopportunity to participate.The proposed code or standard was made available for public reviewand comment that provides an opportunity for additional public input from industry,academia,regulatory 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 inconnection withany itemsmentioned inthis document,and doesnot undertaketo insureanyoneutilizing a standardagainst liability for infringementof any applicable letterspatent,nor assumesany such liability.Users of a code or standard are expressly advised that determination of thevalidity of any such patent rights,and the risk of infringement of such rights,is entirely theirown responsibility.Participation by federal agency representative(s)or person(s)affiliated with industry is not tobe interpreted as government or industry endorsement of this code or standard.ASME accepts responsibility for only those interpretations of this document issued inaccordance with the established ASME procedures and policies,which precludes the issuanceof interpretations by individuals.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.The American Society of Mechanical EngineersThree Park Avenue,New York,NY 10016-5990Copyright 2002 byTHE AMERICAN SOCIETY OF MECHANICAL ENGINEERSAll Rights ReservedPrinted in U.S.A.CONTENTSForeword.vStandards Committee Roster.viiCorrespondence With the B18 Committee.ix1Scope.12Comparison With ISO 4162.13Referenced Standards.14Terminology.25Dimensions.26Top of Head.27Head Height.28Wrenching Height.29Corner Fill.210Gaging of Hex Flange Head.211Position of Head.212Flange.213Bearing Surface.214Fillet.315Body Diameter.316Length.417Points.418Straightness.519Threads.519.15Thread Series and Tolerance Class.iii19.27Thread Gaging.20Thread Length.720.18Grip Length,Lg.20.28Body Length,Ls.20.39Thread Length,(B).20.49Transition Thread Length,(X).21Materials and Mechanical Properties.921.19Steel.21.29Corrosion-Resistant Steels.21.39Nonferrous Metals.22Identification Symbols.922.110Property Class Symbols.22.210Source Symbols.23Finish.1024Workmanship.1025Inspection and Quality Assurance.1026Dimensional Conformance.1027Clearance Holes.1028Designation.10Tables1Gaging of Hex Flange Head.32Tolerance Zones.33Dimensions of Type F Underhead Fillets.44Dimensions of Type U Underhead Fillets.55Dimensions of Hex Flange Screws.66Dimensions of Reduced Body Diameter(Type R).77Length Tolerances.78Dimensions of Points.79Maximum Grip Lengths,Lg,and Minimum Body Lengths,Ls.810Thread Lengths.9Nonmandatory AppendicesAComparison With ISO Standards.11BScrew Straightness Gage and Gaging Procedure.13ivFOREWORDAmerican National Standards Committee B18 for the standardization of bolts,screws,nuts,rivets,and similar fasteners was organized in March 1922 as Sectional CommitteeB18 under the aegis of the American Engineering Standards Committee(later the AmericanStandards Association,then the United States of America Standards Institute and,as ofOctober 6,1969,the American National Standards Institute,Inc.),with the Society ofAutomotive Engineers and the American Society of Mechanical Engineers as joint sponsors.Subcommittee 2 was subsequently established and charged with the responsibility for technicalcontent of standards covering wrench head bolts and nuts.At its meeting on December 4,1974,Committee B18 authorized preparation of a seriesof standards for metric fasteners.Subcommittee 2 was assigned responsibility for developingstandards for metric hex bolts,screws,and nuts.At a meeting on September 22,1976,Subcommittee 2 organized the contents of astandard covering eight different hex head screw and bolt products.Actual drafting waspostponed until ISO/TC2 could reach