1、 Date of Issuance: August 31, 2000The 2000 edition of this Standard is being issued with an automatic addendasubscription service. The use of an addenda allows revisions made inresponse to public review comments or committee actions to be publishedas necessary. The next edition of this Standard is s
2、cheduled for publicationin 2005.ASME issues written replies to inquiries concerning interpretations oftechnical aspects of this Standard. The interpretations will be included withthe above addenda service.ASME is the registered trademark of The American Society of Mechanical Engineers.This code or s
3、tandard 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
4、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
5、 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 infringement of any applicable letters patent, nor assumeany such liability. Users o
6、f 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
7、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
8、 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 2000 byTHE AMERICAN SOCIETY OF MECHANICAL ENGINEERSAll Rights ReservedPrinted i
9、n U.S.A.FOREWORDASME Standards Committee B18 for the standardization of bolts, screws, nuts, rivets,and similar fasteners was organized in March 1922 as Sectional Committee B18 under theaegis of the American Engineering Standards Committee (later the American StandardsAssociation, then the United St
10、ates of American Standards Institute, and, as of October 6,1969, the American National Standards Institute, Inc.). The Society of Automotive Engineersand the American Society of Mechanical Engineers served as joint sponsors.Subcommittee 3 was subsequently established and charged with the responsibil
11、ity fortechnical content of standards covering slotted and recessed head screws. In accordancewith a general realignment of the subcommittee structure on April 1, 1966, Subcommittee3 was redesignated Subcommittee 6.At its meeting on December 4, 1974, Standards Committee B18 authorized preparationof
12、a series of standards for metric fasteners. Subcommittee 6 was assigned the responsibilityfor developing product standards covering metric machine screws and tapping screws.In subsequent meetings of Subcommittee 6, held over the ensuing two years, the contentof the proposed metric standards was disc
13、ussed and organized. It was decided the coverageshould be limited to flat countersunk, oval countersunk, and pan head styles having slottedand Types I and IA cross-recessed drive provisions and the hex and hex washer headdesigns. The spaced thread tapping screws would cover soft converted sizes 2.2,
14、 2.9, 3.5,4.2, 4.8, 5.5, 6.3, 8, and 9.5 for Types AB and B thread-forming screws and Types BFand BT thread-cutting designs. Metric coarse series thread sizes 2, 2.5, 3, 3.5, 4, 5, 6, 8,and 10 would apply for Types D, F, and T thread-cutting tapping screws. Also, it was theconsensus that the respect
15、ive head envelopes for both machine screws and tapping screwsof comparable sizes should remain consistent with established inch practices. In 1976, theIndustrial Fasteners Institute published IFI-502, documenting dimensions and specificationsas then agreed upon and coordinated to the extent possible
16、 with International Organizationfor Standardization (ISO) proposals, which Subcommittee 6 authorized as a first draftproposal for the metric tapping screw document.Because the common head for machine and tapping screw approach differed considerablyfrom existing metric practices and ISO drafts, parti
17、cularly in regard to countersunk heads,a task group was established at the September 1977 meeting of the subcommittee to developproportions for a common 90-deg flat countersunk recessed head having adequate head-to-shank strength combined with satisfactory driveability. Also at this meeting, it was
18、recom-mended that consideration be given to developing a hex flange head having a smaller hexwidth across flats, similar to the metric hex flange screws evolving under Subcommittee 2for larger product sizes. This head would be applicable to both machine and tapping screwsand would be intended to rep
19、lace the hex washer head, which, in some sizes, was difficultto manufacture and had less than desirable driving capabilities. Over the ensuing years, therecommendations resulting from the task group studies along with other actions taken bySubcommittee 6 were coordinated through Subcommittee 4 with
20、the appropriate ISO/TC2working groups toward resolution of dimensional differences. At the March 1980 meetingof ISO/TC2, tentative agreement was reached on the envelopes for the flat, oval, pan, andhex heads. These actions were confirmed by Subcommittee 6 at the October 22, 1980meeting, and a review
21、 of the cross-recess dimensions was initiated. At the December 9,iii1981 meeting, the subcommittee, following approval of the proposed format, authorizedpreparation of a formal draft standard that would include substituting the hex flange headfor the hex washer head. On May 26, 1982 it was agreed to
22、 add a short shoulder underthe head of heat-treated flat countersunk head screws, and approval was granted for numerousother refinements.A proposed draft of the standard was prepared and approved by letter ballot to Subcommittee6 and ASME Standards Committee B18 on June 24, 1985. Following acceptanc
23、e by theserespective groups, this proposal was approved by the sponsors and submitted by the ASMEBoard of Standardization to the American National Standards Institute. It was approved andformally designated an American National Standard on February 3, 1986.In 1997 Subcommittee 6 initiated work to re
24、vise the head diameters for flat head screws,length measurement method for oval head screws, height inspection for oval head screws,and quality assurance. Protrusion height inspection for oval head screws, ductility testing,and hydrogen embrittlement testing were also added. These changes were ballo
25、ted andapproved by the ASME B18 Committee. The proposal was submitted to the AmericanNational Standards Institute and designated an American National Standard on May 19, 2000.ivASME STANDARDS COMMITTEE B18Standardization of Bolts, Nuts, Rivets, Screws, Washers,and Similar Fasteners(The following is
26、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. C. Akins, Safety Socket Screw Corp.J. Altman, Rotor Clip Co.J. H. Slass, Alternate, Rotor Clip Co.J. B. Belford,
27、Lawson Products, Inc.D. Broomfieid, ITW Shakeproof Industrial ProductsJ. A. Buda, SPS TechnologiesD. A. Clever, Deere and Co.T. Collier, Cam-Tech Industries, Inc.R. L. Crane, The American Society of Mechanical EngineersA. C. Dicola, Wrought Washer Manufacturing, Inc.A. Dinh, Defense Industrial Suppl
28、y CenterW. D. Downing, ConsultantD. L. Drobnich, Ford Motor CompanyB. A. Dusina, Federal Screw WorksD. S. George, Ford Motor Co.B. Hasiuk, Defense Industrial Supply CenterA. Herskovitz, ConsultantA. C. Hood, ACH TechnologiesJ. Hubbard, Rockford Fastener, Inc.F. W. Kern, Society of Automotive Enginee
29、rsJ. F. Koehi, Spirol International Corp.W. H. Kopke, ITW Shakeproof Industrial ProductsJ. G. Langenstein, Caterpillar, Inc.M. Levinson, ITW Shakeproof Industrial ProductsL. L. Lord, Caterpillar, Inc.A. D. McCrindle, Genfast Manufacturing Co.K. E. McCuIlough, ConsultantR. F. Novotny, TextronW. Schev
30、ey, BGM Fastener Co., inc.R. D. Strong, General Motors Corp.J. F. Sullivan, Accurate Fasteners, Inc.R. L Tennis, Caterpillar, Inc.S. W. Vass, Lake Erie Screw Corp./IFIC. B. Wackrow, MND Corp.R. G. Weber, BEI School of Engineering, Fairfield UniversityW. K, Wilcox, Naval Sea System CommandC. J. Wilso
31、n, Industrial Fasteners InstituteVSUBCOMMITTEE 6 SLOTTED AND RECESSED HEADSCREWSR. D. Strong, Chair, General Motors Corp.R, L. Crane, Secretary, The American Society of Mechanical EngineersD. Broomfield, ITW Shakeproof Industrial ProductsD. A. Clever, Deere and Co,M, Dailey, Barnes and Reineuke, Inc
32、.A. Dinh, Defense Industrial Supply CenterD. L. Drobnich, Ford Motor CompanyJ. Greenslade, Greenslade and Co.A. Herskovitz, ConsultantM. W. Holubecki, Electric Boat Corp.J. Hubbard, Rockford Fastener, Inc.R. W. Kerr, Kerr Lakeside, Inc.R. F. Novotny, TextronJ. A. Schlink, Caterpillar, Inc.R. D. Stro
33、ng, General Motors Corp.J. F. SuHivan, Accurate Fasteners, Inc.C. B. Wackrow, MNP Corp.W. K. Wilcox, Naval Sea System CommandC. J. Wilson, Industrial Fasteners InstituteviCORRESPONDENCE WITH B18 COMMITTEEGeneral. ASME Standards are developed and maintained with the intent to represent theconsensus o
34、f concerned interests. As such, users of this Standard may interact with theCommittee by requesting interpretations, proposing revisions, and attending Committeemeetings. Correspondence should be addressed to:Secretary, BIS Main CommitteeThe American Society of Mechanical EngineersThree Park AvenueN
35、ew York, NY 10016-5990Proposing Revisions. Revisions are made periodically to the Standard to incorporatechanges 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
36、proposals for revisions to this Standard. Such proposals shouldbe as specific as possible, citing the paragraph 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 rend
37、er an interpretation of anyrequirement of the Standard. Interpretations can only be rendered in response to a writtenrequest sent to the Secretary of the B18 Main Committee.The request for interpretation should be clear and unambiguous. It is further recommendedthat the inquirer submit his/her reque
38、st in the following format:Subject: Cite the applicable paragraph number(s) and the topic of the inquiry.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 specificrequirement suita
39、ble for general understanding and use, not as a requestfor an approval of a proprietary design or situation. 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 f
40、ormat will be rewritten in this format by the Committeeprior to being answered, which may inadvertently 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. Furth
41、er, persons aggrieved byan interpretation may appeal to the cognizant ASME Committee or Subcommittee. ASMEdoes not “approve,“ “certify,“ “rate,“ or “endorse“ any item, construction, proprietary device,or activity.Attending Committee Meetings. The B18 Main Committee regularly holds meetings, whichare
42、 open to the public. Persons wishing to attend any meeting should contact the Secretaryof the B18 Main Committee.viiCONTENTSForeword iiiStandards Committee Roster vCorrespondence With B18 Committee vii1 Introductory Motes 11.1 Scope I1.2 Comparison With ISO Standards 11.3 Head Types1.4 Screw Types a
43、nd Application 21.5 Assembly Considerations1.6 Dimensions 21.7 Options1.8 Terminology1.9 Designation 31.10 Referenced Standards1.11 Inspection and Quality Assurance 32 General Data 42.1 Screw Heads2.2 Length2.3 Threads and Points 52.4 Thread Length2.5 Body Diameter 72.6 Straightness2.7 Material and
44、Heat Treatment 72.8 Finishes2.9 Workmanship3 Performance Requirements and Tests for Steel Tapping Screws 73.1 Purpose 73.2 Drive Test for Types AB, B, D, F, and T Screws 73.3 Torsional Strength Test for All Types of Screws 83.4 Ductility Test 83.5 Hydrogen Embrittlement Test 83.6 Material and Proces
45、sing Requirements 9Figure1 Typical Torsional Strength Test FixtureTables1 Thread Lengths for Types AB, B, BF, and BT Tapping Screws 52 Thread Lengths for Types D, F, and T Tapping Screws 63 Standard Test Plate Thicknesses and Hole Sizes for Drive Test Inspection of TappingScrews 8ix4 Torsional Stren
46、gth Requirements for Tapping Screws 95 Dimensions of Threads and Points for Types AB and B Thread-Forming Tapping Screws 106 Dimensions of Threads and Points for Types BF and BT Thread-Cutting Tapping Screws 117 Dimensions of Threads and Points for Types D, F, and T Thread-Cutting Tapping Screws 128
47、 Dimensions of Slotted Flat Countersunk Head Tapping Screws 139 Dimensions of Type 1 Cross-Recessed Flat Countersunk Head Tapping Screws 1410 Dimensions of Type IA Cross-Recessed Flat Countersunk Head Tapping Screws 611 Dimensions of Type III Square-Recessed Flat Countersunk Head Tapping Screws 1812
48、 Dimensions of Slotted Oval Countersunk Head Tapping Screws 2013 Dimensions of Type I Cross-Recessed Oval Countersunk Head Tapping Screws 2214 Dimensions of Type IA Cross-Recessed Oval Countersunk Head Tapping Screws 415 Dimensions of Type III Square-Recessed Oval Countersunk Head Tapping Screws 261
49、6 Dimensions of Slotted Pan Head Tapping Screws 2817 Dimensions of Type I Cross-Recessed Pan Head Tapping Screws 2918 Dimensions of Type IA Cross-Recessed Pan Head Tapping Screws 3019 Dimensions of Type III Square-Recessed Pan Head Tapping Screws 120 Dimensions of Hex Head Tapping Screws 3221 Dimensions of Hex Flange Head Tapping Screws 322 Recommended Nominal Screw Lengths for Tapping Screws 3523 Chemical Composition Limits 3524 Total Case Depth 5Mandatory AppendicesI Protrusion Gaging of Flat and Oval Counters
