1、Metric Heavy Hex ScrewsAN AMERICAN NATIO NAL STANDARDRevision of ANSI B18.2.3.3M-1979(R2001)ASME B18.2.3.3M-2007REAFFIRMED 2014FOR CURRENT COMMITTEE PERSONNELPLEASE E-MAIL CSasme.orgIntentionally left blankASME B18.2.3.3M-2007Revision of ANSI B18.2.3.3M-1979(R2001)Metric HeavyHex ScrewsAN AMERICAN N
2、ATIONAL STANDARDThree Park Avenue New York,NY 10016Date of Issuance:October 31,2007This Standard will be revised when the Society approves the issuance of a new edition.There willbe no addenda issued to this edition.ASME issues written replies to inquiries concerning interpretations of technical asp
3、ects of thisStandard.Periodically,certain actions of the ASME B18 Committee may be published as Cases.Casesand interpretations are published on the ASME Web site under the Committee Pages athttp:/cstools.asme.org as they are issued.ASME is the registered trademark of The American Society of Mechanic
4、al Engineers.This code or standard was developed under procedures accredited as meeting the criteria for American NationalStandards.The Standards Committee that approved the code or standard was balanced to assure that individuals fromcompetent and concerned interests have had an opportunity to part
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9、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 2007 byTHE AMERICAN SOCIETY OF MECHANICAL ENGINEERSAll rights reservedPrint
10、ed in U.S.A.CONTENTSForeword.ivCommittee Roster.vCorrespondence With the B18 Committee.vi1Introductory Notes.12General Data.1Figures1Fillet Detail for Short Screws.32Fillet Detail for Long Screws.3Tables1Tolerance Zone.22Dimensions of Heavy Hex Screws.33Dimensions of Underhead Fillets.44Length Toler
11、ances.45Dimensions of Points.46Maximum Grip Gaging Lengths and Minimum Body Lengths.57Thread Lengths.6Nonmandatory AppendicesAScrew Straightness Gage and Gaging Procedure.9BBody Position Gages and Gaging Procedures.10iiiFOREWORDAmerican National Standards Committee B18 for the standardization of bol
12、ts,screws,nuts,rivets,and similar fasteners was organized in March 1922 as Sectional Committee B18 underthe aegis of the American Engineering Standards Committee(later the American StandardsAssociation,then the United States of America Standards Institute and,as of October 6,1969,the American Nation
13、al Standards Institute,Inc.)with the Society of Automotive Engineers andtheAmericanSocietyofMechanicalEngineersasjointsponsors.Subcommittee2wassubsequentlyestablishedandchargedwiththeresponsibilityfortechnicalcontentofstandardscoveringwrenchhead bolts and nuts.At its meeting on December 4,1974,Commi
14、ttee B18 authorized preparation of a series ofstandards for metric fasteners.Subcommittee 2 was assigned responsibility for developing stan-dards for metric hex bolts,screws,and nuts.At a meeting on September 22,1976,Subcommittee 2 organized the contents of a standardcovering eight different hex hea
15、d screw and bolt products.Actual drafting was postponed untilISO/TC2 could reach final decisions relating to basic dimensions and characteristics of hex bolts,screws,andnuts.AtISO/TC2meetingsheldinApril1977,finalactionsweretaken.CommitteeB18affirmed the TC2 decisions at a meeting on June 29,1977,and
16、 drafting of this Standard wasstarted.In February 1978,Committee B18 established a cooperative program with the Department ofDefense to draft American National Standards for metric fasteners in such a way that they couldbe used directly by the Government for procurement purposes.The Department of Defenserequested that each of the eight products be covered in separate standards,and Subcommittee 2accepted this approach at its meeting on June 27,1978.The 1979 Edition was approved by ballot of Commi