1、AN AMERICAN NATIO NAL STANDARDASME B18.2.1-2010Revision of ASME B18.2.1-1996(R2005)Square,Hex,Heavy Hex,and Askew Head Bolts and Hex,Heavy Hex,Hex Flange,Lobed Head,and Lag Screws(Inch Series)INTENTIONALLY LEFT BLANK标准分享网 w w w.b z f x w.c o m 免费下载w w w.b z f x w.c o mASME B18.2.1-2010Revision of AS
2、ME B18.2.1-1996(R2005)Square,Hex,HeavyHex,and Askew HeadBolts and Hex,HeavyHex,Hex Flange,Lobed Head,and LagScrews(Inch Series)AN AMERICAN NATIONAL STANDARDThree Park Avenue New York,NY 10016 USAw w w.b z f x w.c o mDate of Issuance:October 13,2010This Standard will be revised when the Society appro
3、ves the issuance of a new edition.There willbe no addenda issued to this edition.ASME issues written replies to inquiries concerning interpretations of technical aspects of thisStandard.Interpretations are published on the ASME Web site under the Committee Pages athttp:/cstools.asme.org as they are
4、issued.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 for American NationalStandards.The Standards Committee that approved the code or standard was balanced to assure that indivi
5、duals fromcompetent and concerned interests have had an opportunity to participate.The proposed code or standard was madeavailable forpublic review andcomment thatprovides an opportunityfor additional publicinput from industry,academia,regulatory agencies,and the public-at-large.ASME does not“approv
6、e,”“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 anyitems mentioned in this document,and does not undertake to insure anyone utilizing a standard against liability f
7、orinfringement of any applicable letters patent,nor assumes any such liability.Users of a code or standard are expresslyadvised that determination of the validity of any such patent rights,and the risk of infringement of such rights,isentirely their own responsibility.Participation by federal agency
8、 representative(s)or person(s)affiliated with industry is not to be interpreted asgovernment or industry endorsement of this code or standard.ASME accepts responsibility for only those interpretations of this document issued in accordance with the establishedASME procedures and policies,which preclu
9、des the issuance of 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
10、 2010 byTHE AMERICAN SOCIETY OF MECHANICAL ENGINEERSAll rights reservedPrinted in U.S.A.标准分享网 w w w.b z f x w.c o m 免费下载w w w.b z f x w.c o mCONTENTSForeword.ivCommittee Roster.viiCorrespondence With the B18 Committee.viii1Introduction.12General Data for Both Bolts and Screws.23Bolts.44Screws.85Lag
11、Screws.20Figures1Underhead Fillet for Long Screws.152Underhead Fillet for Short Screws Threaded Full Length.153LG,Maximum and LB,Minimum for Short Screws Threaded Full Length.15Tables1Dimensions of Square Head Bolts.42Dimensions of Hex Bolts.53Dimensions of Heavy Hex Bolts.64Dimensions of Askew Head
12、 Bolts.75Length Tolerances for Bolts.76Dimensions of Hex Cap Screws.97Dimensions of Heavy Hex Screws.118Dimensions of Hex Flange Screws.129Dimensions of Lobe Head Screws.1410Dimensions of Underhead Fillets.1511LG,Maximum and LB,Minimum Limitations for Short Screws ThreadedFull Length.1612Maximum Gri
13、p Gaging Lengths,LG,and Minimum Body Lengths,LB,for Screws.1713Length Tolerances for Screws.2014Dimensions of Square Lag Screws.2115Dimensions of Hex Lag Screws.2216Dimensions of Lag Screw Threads.22Mandatory AppendixIGage and Gaging Practices for External Lobed Head Drive System.23Nonmandatory Appe
14、ndicesAFormulas for Bolt and Screw Head Dimensions.26BWeight in Pounds of 100 Steel Hex Cap Screws for Given Diameter/LengthCombination.28CCountersunk Center Holes.29iiiw w w.b z f x w.c o mFOREWORDAmerican National Standards Committee B18 for the standardization of bolts,screws,nuts,rivets,and simi
15、lar 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 National Standards Institute,Inc.),w
16、ith the Society of Automotive Engineers andThe American Society of Mechanical Engineers as joint sponsors.Subcommittee 2 was subse-quentlyestablishedandchargedwiththeresponsibilityfortechnicalcontentofstandardscoveringwrench head bolts and nuts.Subcommittee 2,after appraisal of therequirements of industry,developed a proposed standardseries of bolt head and nut dimensions.This proposal was finally approved and designated atentative American Standard in February 1927.A first revision of the docum