1、ASME B18.2.3.4M-2001Revision of ANSI/ASME B18.2.3.4M-1984 (R1995)METRIC HEXFLANGE SCREWSAN AMERICAN NATIONAL STANDARDREAFFIRMED 2011FOR CURRENT COMMITTEE PERSONNELPLEASE E-MAIL CSasme.orgIntentionally left blank AN AMERICAN NATIONAL STANDARDMETRIC HEXFLANGE SCREWSASME B18.2.3.4M-2001Revision of ANSI
2、/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 regi
3、stered 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 an
4、d 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
5、 “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 with any items mentioned in this document, and does not undertake to insure anyoneutilizing a standard against liability for infri
6、ngement of any applicable letters patent, 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 rep
7、resentative(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 preclud
8、es 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
9、 2002 byTHE AMERICAN SOCIETY OF MECHANICAL ENGINEERSAll Rights ReservedPrinted in U.S.A.CONTENTSForeword . vStandards Committee Roster viiCorrespondence With the B18 Committee . ix1 Scope 12 Comparison With ISO 4162 . 13 Referenced Standards . 14 Terminology . 25 Dimensions 26 Top of Head . 27 Head
10、Height . 28 Wrenching Height . 29 Corner Fill . 210 Gaging of Hex Flange Head . 211 Position of Head 212 Flange . 213 Bearing Surface . 214 Fillet . 315 Body Diameter 316 Length . 417 Points . 418 Straightness . 519 Threads 519.1 5Thread Series and Tolerance Class .iii19.2 7Thread Gaging 20 Thread L
11、ength 720.1 8Grip Length, Lg.20.2 8Body Length, Ls.20.3 9Thread Length, (B) 20.4 9Transition Thread Length, (X) 21 Materials and Mechanical Properties 921.1 9Steel 21.2 9Corrosion-Resistant Steels 21.3 9Nonferrous Metals .22 Identification Symbols 922.1 10Property Class Symbols 22.2 10Source Symbols
12、 .23 Finish 1024 Workmanship . 1025 Inspection and Quality Assurance . 1026 Dimensional Conformance . 1027 Clearance Holes 1028 Designation . 10Tables1 Gaging of Hex Flange Head . 32 Tolerance Zones 33 Dimensions of Type F Underhead Fillets . 44 Dimensions of Type U Underhead Fillets . 55 Dimensions
13、 of Hex Flange Screws . 66 Dimensions of Reduced Body Diameter (Type R) . 77 Length Tolerances . 78 Dimensions of Points 79 Maximum Grip Lengths, Lg, and Minimum Body Lengths, Ls. 810 Thread Lengths . 9Nonmandatory AppendicesA Comparison With ISO Standards . 11B Screw Straightness Gage and Gaging Pr
14、ocedure . 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,
15、 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.Subcommittee2wassubsequentlyestablishedandchargedwiththerespo
16、nsibilityfortechnicalcontent 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 nu
17、ts.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 fina decisions relating to basic dimensions andcharacteristics of hex bolts, screws, and nuts. A
18、t ISO/TC2 meetings held in April 1977,fina actions were taken. Committee B18 affirme the TC2 decisions at a meeting on June29, 1977, and drafting of this Standard was started.In February 1978, Committee B18 established a cooperative program with the Departmentof Defense to draft American National St
19、andards for metric fasterners in such a way thatthey could be used directly by the government for procurement purposes. The Departmentof Defense requested that each of the eight products be covered in separate standards, andSubcommittee 2 accepted this approach at its meeting on June 27, 1978. The s
20、tandard wasapproved by the secretariat and submitted to the American National Standards Institute fordesignation as an American National Standard. This was granted on May 17, 1979.ANSI B18.2.3.4M-1979 was introduced to ISO/TC2 by the United States of Americawith the recommendation that it be conside
21、red as the basis for development of ISO standardsfor metric hex flang screws. At the March 1980 ISO/TC2 meetings, the Canadian delegationwasinvitedtoacceptresponsibilityforananalyticalresearchstudytoexaminetherelationshipsbetween wrenchability, head material volume, head proportioning, and manufactu
22、ring conve-nience. Stelco, Inc., conducted the study with E. M. Alexander supervising.Following these ISO/TC2 meetings, the Canadian research was reviewed, and based onthe findings designs of metric hex flang and metric heavy hex flang screws wereestablished. Preparation of ISO standards for both se
23、ries of flang screws was authorized.Following these ISO/TC2 decisions, B18 subcommittee 2 initiated this revision of ANSIB18.2.3.4M-1979 with the purpose being to bring it into conformance with the proposedISO standards. Relatively few changes were necessary; the principal ones included:(a) disconti
24、nuation of size M20(b) modest adjustments in values for flang diameters bearing circle diameters, headheights, and wrenching heights(c) slight change in width across corners tolerances(d) a more effective and simplifie technique for gaging the headThis revised Standard is in essential accord with IS
25、O standards now under development.vThis revision was approved by letter ballot of Subcommittee 2. Following its approvalby letter ballot of the B18 Committee and the American Society of Mechanical Engineers,the revision was submitted to the American National Standards Institute for recognition asan
26、American National Standard. This was granted on March 23, 1984.The changes in this 2001 revision follow those made for the metric hex cap screw andinclude the following:(a) The government standard items and part numbering system of Appendix III is deletedand replaced by a B18 standard part numbering
27、 reference to ASME B18.24.1 found inpara. 28.1.(b) Paragraph 7 makes clear that the head height does not include raised markings.(c) Bearing face runout is now to be measured on the actual bearing circle instead ofat a minimum bearing cirle as described in para. 13.(d) Straightness at maximum materi
28、al condition is specifed. A rail gage replaces thesleeve gage as specifed in para. 18.(e) The transition threads shall have a rounded root contour. This replaces the requirementof a rounded root contour, no radius of which shall be less than the specifed minimumat the root of the full form thread fo
29、r Property Class 10.9 and higher, per para. 20.4.(f) In Tables 1 and 5 for M16, the head height, K max., the wrenching height, Kwmin.,and the thickness of Gage A, Tamax., and Tamin., are each increased by 0.1 mm toagree with ISO/DIS 4162.2.(g) A new Nonmandatory Appendix A details a comparison with
30、ISO 4162 and ISO/DIS 4162.2.(h) Dimensional conformance has been specifed in para. 26.(i) Workmanship and accordance with ASTM F 788/F 788M is specifed in para. 24.This Standard was approved by the American National Institute on March 9, 2001.viASME B18 STANDARDS COMMITTEEStandardization of Bolts, N
31、uts, Rivets, Screws,Washers, and Similar Fasteners(The following is the roster of the Committee at the time of approval of this Standard.)OFFICERSD. A. Clever, ChairR. D. Strong, Vice ChairS. W. Vass, Vice ChairR. L. Crane, SecretaryCOMMITTEE PERSONNELJ. Altman, Rotor Clip Co.J. H. Slass, Alternate,
32、 Rotor Clip Co.J. B. Belford, Lawson Products, Inc.J. A. Buda, SPS TechnologiesR. M. Byrne, Trade Association Management, Inc.D. A. Clever, Deere and Co.A. P. Cockman, Ford Motor Co.T. Collier, Cam-Tech Industries, Inc.R. L. Crane, The American Society of Mechanical EngineersA. C. DiCola, Wrought Wa
33、sher Co.B. A. Dusina, Federal Screw WorksD. S. George, Ford Motor Co.D. L. Drobnich, Alternate, Ford Motor Co.J. Greenslade, Greenslade and Co.B. Hasiuk, Defense Industrial Supply CenterA. Herskovitz, U.S. ArmyJ. Hubbard, Rockford Fastener, Inc.D. F. Kattler, SPS TechnologiesJ. F. Koehl, Spirol Inte
34、rnational Corp.W. H. Kopke, ITW Shakeproof Assembly Co.M. Levinson, Alternate, ITW Shakeproof Assembly Co.J. G. Langenstein, ConsultantD. Liesche, Defense Industrial Supply CenterL. L. Lord, Caterpillar, Inc.R. L. Tennis, Alternate, Caterpillar, Inc.D. B. Mantas, GEEmpisA. D. McCrindle, Genfast Manu
35、facturing Co.K. E. McCullough, ConsultantR. B. Meade, Textron Fastening SystemsM. D. Prasad, General Motors Corp.S. Savoji, ITW MedalistW. Schevey, BGM Fastener Co., Inc.R. D. Strong, General Motors Corp.J. F. Sullivan, National Fasteners Distribution AssociationR. Torres, Action Threaded Production
36、S. W. Vass, Lake Erie Screw Corp.C. B. Wackrow, MNP Corp.R. G. Weber, Fairfield UniversityviiW. K. Wilcox, Naval Sea SystemsC. J. Wilson, Industrial Fasteners InstituteD. R. Akers, Alternate, Industrial Fasteners InstituteR. B. Wright, Wright Tool Co.J. G. Zeratsky, Tubular and Machine InstituteSUBC
37、OMMITTEE 2 EXTERNALLY DRIVEN FASTENERSS. W. Vass, Chair, Lake Erie Screw Corp.R. L. Crane, Secretary, The American Society of Mechanical EngineersH. S. Brenner, Almay Research and TestingR. M. Byrne, Trade Association Management, Inc.M. M. Chu, Nucor FastenerD. A. Clever, Deere and Co.A. P. Cockman,
38、 Ford Motor Co.R. J. Corbett, Huck InternationalE. R. Cossairt, Hill Fastener Corp.D. L. Drobnich, Ford Motor Co.B. A. Dusina, Federal Screw WorksD. S. George, Ford Motor Co.J. Greenslade, Greenslade and Co.A. Herskovitz, ConsultantM. W. Holubecki, Electric Boat Corp.J. Hubbard, Rockford Fastener, I
39、nc.D. F. Kattler, SPS TechnologiesD. Liesche, Defense Industrial Supply CenterL. L. Lord, Caterpillar, Inc.D. B. Mantas, GEEmpisA. D. McCrindle, Genfast Manufacturing Co.K. E. McCullough, ConsultantR. B. Meade, Textron Fastening SystemsS. Savoji, ITW MedalistJ. A. Schlink, Caterpillar, Inc.D. F. Sha
40、rp, Turnasure LLCW. R. Stevens, MacLeanFogg FasteningR. D. Strong, General Motors Corp.J. F. Sullivan, National Fasteners Distribution AssociationD. M. Sutula, Industrial Fasteners InstituteR. L. Tennis, Caterpillar, Inc.R. Torres, Action Threaded ProductsC. B. Wackrow, MNP Corp.W. L. Wilcox, Naval
41、Sea SystemsC. J. Wilson, Industrial Fasteners InstituteviiiCORRESPONDENCE WITH B18 COMMITTEEGeneral. ASME Standards are developed and maintained with the intent to represent theconsensus of concerned interests. As such, users of this Standard may interact with theCommittee by requesting interpretati
42、ons, proposing revisions, and attending Committeemeetings. Correspondence should be addressed to:Secretary, B18 Standards CommitteeThe American Society of Mechanical EngineersThree Park AvenueNew York, NY 10016-5990Proposing Revisions. Revisions are made periodically to the Standard to incorporatech
43、anges that appear necessary or desirable, as demonstrated by the experience gained fromthe application of the Standard. Approved revisions will be published periodically.The Committee welcomes proposals for revisions to this Standard. Such proposals shouldbe as specifc as possible, citing the paragr
44、aph number(s), the proposed wording, and adetailed description of the reasons for the proposal, including any pertinent documentation.Interpretations. Upon request, the B18 Committee will render an interpretation of anyrequirement of the Standard. Interpretations can only be rendered in response to
45、a writtenrequest sent to the Secretary of the B18 Standards Committee.The request for interpretation should be clear and unambiguous. It is further recommendedthat the inquirer submit his/her request in the following format:Subject: Cite the applicable paragraph number(s) and the topic of the inquir
46、y.Edition: Cite the applicable edition of the Standard for which the interpretationis being requested.Question: Phrase the question as a request for an interpretation of a specifcrequirement suitable for general understanding and use, not as a requestfor an approval of a proprietary design or situat
47、ion. The inquirer mayalso include any plans or drawings which are necessary to explainthe question; however, they should not contain proprietary names orinformation.Requests that are not in this format will be rewritten in this format by the Committeeprior to being answered, which may inadvertently
48、change the intent of the original request.ASME procedures provide for reconsideration of any interpretation when or if additionalinformation that might affect an interpretation is available. Further, persons aggrieved byan interpretation may appeal to the cognizant ASME Committee or Subcommittee. AS
49、MEdoes not “approve,”“certify,”“rate,” or “endorse” any item, construction, proprietary device,or activity.Attending Committee Meetings. The B18 Standards Committee regularly holds meetings,which are open to the public. Persons wishing to attend any meeting should contact theSecretary of the B18 Standards Committee.ixIntentionally left blank ASME B18.2.3.4M-2001METRIC HEX FLANGE SCREWS1 SCOPE(a) This Standard covers the complete dimensionaland general data for metric series hex flang screwsrecognized as American National Standard.(b) TheinclusionofdimensionaldatainthisStandardis no
