1、Glossary of Terms for Mechanical FastenersAN AMERICAN NATIONAL STANDARDASME B18.12-2012Revision of ASME B18.12-2001 (R2006)ASME B18.12-2012Revision of ASME B18.12-2001 (R2006)Glossary of Termsfor MechanicalFastenersAN AMERICAN NATIONAL STANDARDThree Park Avenue New York, NY 10016 USADate of Issuance
2、: February 23, 2012This Standard will be revised when the Society approves the issuance of a new edition.ASME issues written replies to inquiries concerning interpretations of technical aspects of thisStandard. Periodically certain actions of the ASME B18 Committee may be published as Cases.Cases an
3、d interpretations are published on the ASME Web site under the Committee Pages athttp:/cstools.asme.org/ as they are issued.Errata to codes and standards may be posted on the ASME Web site under the Committee Pages toprovide corrections to incorrectly published items, or to correct typographical or
4、grammatical errorsin codes and standards. Such errata shall be used on the date posted.The Committee Pages can be found at http:/cstools.asme.org/. There is an option available toautomatically receive an e-mail notification when errata are posted to a particular code or standard.This option can be f
5、ound on the appropriate Committee Page after selecting “Errata” in the “PublicationInformation” section.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 NationalStanda
6、rds. The Standards Committee that approved the code or standard was balanced to assure that individuals fromcompetent and concerned interests have had an opportunity to participate. The proposed code or standard was madeavailable for public review and comment that provides an opportunity for additio
7、nal 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 in connection with an
8、yitems mentioned in this document, and does not undertake to insure anyone utilizing a standard against liability forinfringement 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 r
9、ights, and the risk of infringement of such rights, isentirely their own responsibility.Participation by federal agency 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
10、those interpretations of this document issued in accordance with the establishedASME procedures and policies, which precludes 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
11、 permission of the publisher.The American Society of Mechanical EngineersThree Park Avenue, New York, NY 10016-5990Copyright 2012 byTHE AMERICAN SOCIETY OF MECHANICAL ENGINEERSAll rights reservedPrinted in U.S.A.CONTENTSForeword ivCommittee Roster . vCorrespondence With the B18 Committee vi1 Introdu
12、ction . 12 Terminology . 13 Product Families . 23Tables1 Common Applications of Threaded Fastener Head Styles 82 Type Designations for Tapping Screws and Metallic Drive Screws 333 Screw and Washer Assembly Combinations . 40Index 55iiiFOREWORDSectional Committee B18 on DimensionalStandardization of B
13、olts, Nuts, Rivets, Screws, and Simi-lar Fasteners was organized in March 1922 under theprocedure of the American Standards Association withthe Society of Automotive Engineers and The AmericanSociety of Mechanical Engineers as joint sponsors.Subcommittee 10 on the Glossary of Terms forMechanical Fas
14、teners was organized in February 1947.The purpose of the subcommittee was to promote andcoordinate the standardization of fastener nomenclaturefor those products falling under the scope of the variousother subcommittees of the B18 Sectional Committee,the definitions themselves being the responsibili
15、ty ofthe cognizant subcommittee. It was later decided thatterms not strictly in the above category but closely alliedshould be defined in the Glossary.During the development period, several drafts of theGlossary were prepared and studied by Subcommittee10 before a suitable format and content could b
16、e agreedupon.To cover completely the field of mechanical fasteners,it has been necessary to include in this Standard illustra-tions of certain fastener features and types of fastenersthat are of proprietary origin. Because it was impossibleto include all variations of such proprietary designs, thisS
17、tandard includes selected illustrations that exemplifythe type of fastener or feature described. This selectionwas made on an impartial basis. The inclusion of any oneivproprietary design in this Standard does not constituteendorsement by the committee or the sponsors, nor isomission of certain styl
18、es to be construed as rejectionof such styles by the committee and sponsors.ASA B18.12 was approved by the B18 SectionalCommittee, the sponsors, and the American StandardsAssociation, and it was designated as an AmericanStandard on June 22, 1962.In May 1995, Subcommittee 12 of the B18 StandardsCommi
19、ttee set forth the concept that a complete updateand significant revision of the Glossary of Terms wasnecessary. The content was completely reorganized toreflect a logical approach to basic fastener characteristicsand configurations. Many new sections and items, suchas blind fasteners and retaining
20、rings, were included.In total, 538 terms were included in the 2001 editionof the Standard. ASME B18.12-2001 was approved bythe American National Standards Institute onAugust 15, 2001.In this edition, para. 3.1.3 was revised in its entirety,and para. 3.1.4 was added.Suggestions for improvement of thi
21、s Standard will bewelcomed. They should be sent to The American Societyof Mechanical Engineers, Secretary, B18 StandardsCommittee, Three Park Avenue, New York, NY 10016-5990.This revision was approved as an American NationalStandard on January 9, 2012.ASME B18 COMMITTEEStandardization of Bolts, Nuts
22、, Rivets, Screws, Washers, andSimilar Fasteners(The following is the roster of the Committee at the time of approval of this Standard.)STANDARDS COMMITTEE OFFICERSJ. Greenslade, ChairD. S. George, Vice ChairR. D. Strong, Vice ChairC. J. Gomez, SecretarySTANDARDS COMMITTEE PERSONNELV. Cartina, Autocr
23、aft IndustrialD. A. Clever, ConsultantA. P. Cockman, Ford Motor Co.C. D. de la Garza, Texas Screw ProductsD. S. George, Ramco SpecialtiesC. J. Gomez, The American Society of Mechanical EngineersJ. Greenslade, Industrial Fasteners InstituteJ. J. Grey, Contributing Member, Fastener Consulting Services
24、, Inc.A. Herskovitz, ConsultantJ. Hubbard, Leland-Powell Fasteners, Inc.J. Jennings, Contributing Member, Naval Surface Warfare CenterW. H. King, Porteous Fastener Co.W. H. Kopke, ConsultantSUBCOMMITTEE 12 GLOSSARY OF TERMSC. J. Wilson, Chair, ConsultantD. A. Clever, ConsultantC. D. de la Garza, Tex
25、as Screw ProductsM. A. Elmi, ConsultantJ. S. Foote, Trade Association Management, Inc.D. S. George, Ramco SpecialtiesJ. Greenslade, Industrial Fasteners InstituteJ. Jennings, Naval Surface Warfare CenterW. H. King, Porteous Fastener Co.W. H. Kopke, ConsultantM. Levinson, ITW Shakeproof Industrial Pr
26、oductsvW. J. Lutkus, Emhart TeknologiesD. A. McCrindle, Canadian Fasteners InstituteM. D. Prasad, Contributing Member, GlobalM however, they shouldnot contain proprietary names or information.Requests that are not in this format may be rewritten in the appropriate format by the Committeeprior to bei
27、ng 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. Further, persons aggrieved by aninterpretation may appeal to the cogniza
28、nt ASME Committee or Subcommittee. ASME does not“approve,” “certify,” “rate,” or “endorse” any item, construction, proprietary device, or activity.Attending Committee Meetings. The B18 Standards Committee regularly holds meetings thatare open to the public. Persons wishing to attend any meeting shou
29、ld contact the Secretary ofthe B18 Standards Committee.viASME B18.12-2012GLOSSARY OF TERMS FOR MECHANICAL FASTENERS1 INTRODUCTION1.1 ScopeThis Standard is a summary of nomenclature and ter-minology currently used to define and/or describemechanical fasteners, related characteristics, and themanufact
30、uring processes that produce these products.Utilization of these terms by manufacturers and con-sumers is intended to reduce or eliminate confusion andserve as a sound basis for communication.(a) Primary Operations. Mechanical fasteners are pro-duced by forming or screw machine operations. Formingis
31、 generally scrapless and, depending upon size, mayproduce fasteners at rates exceeding 500 pieces perminute. Screw machining, although more tightly toler-anced, is significantly slower and generates scrapbecause it involves the removal of material.(b) Secondary Operations. Fasteners generally underg
32、oseveral secondary operations or processes, such asthread rolling, heat treating, or plating.(c) Fastener. A fastener is a mechanical devicedesigned specifically to hold, join, couple, assemble, ormaintain equilibrium of single or multiple components.The resulting assembly may function dynamically o
33、rstatically as a primary or secondary component of amechanism or structure. Based on the intended applica-tion, a fastener is produced with varying degrees ofbuilt-in precision and engineering capability, ensuringadequate, sound service under planned, pre-establishedenvironmental conditions.(d) Bolt
34、s, Studs, Screws, Nuts, Washers, Rivets, Pins, andCustom-Formed Parts. These items are the general prod-uct families in which mechanical fasteners are best classi-fied. Within each product family are numerous typesthat may have a name conforming to the technical lan-guage of a national standard or a
35、lternately may have aname that has its origins in commercial or marketingnomenclature often taken from its intended application.Such names, for example, include the “stove bolt” and“carriage bolt.” Because mechanical fasteners are used injust about every mechanical assembly, they necessarilyhave bee
36、n designed to meet a broad range of applica-tions from watch and computer assembly to the spaceshuttle design. The names given to fasteners appear tobe as limitless as the designers imagination. While manyfasteners may look alike, they generally have definedengineered capabilities based upon their i
37、ntendedapplication.11.2 Referenced DocumentsIn the development of this Standard, a number ofterms were written based upon language found in morethan 230 standards and other publications of the follow-ing organizations:(a) American Society for Testing and Materials(ASTM International), 100 Barr Harbo
38、r Drive, P.O. BoxC700, West Conshohocken, PA 19428-2959(www.astm.org)(b) The American Society of Mechanical Engineers(ASME), Three Park Avenue, New York, NY 10016-5990;Order Department: 22 Law Drive, P.O. Box 2900,Fairfield, NJ 07007-2900 (www.asme.org)(c) Industrial Fasteners Institute (IFI), 6363O
39、ak Tree Boulevard, Independence, OH 44131(www.indfast.org)(d) Society of Automotive Engineers(SAE International), 400 Commonwealth Drive,Warrendale, PA 15096 (www.sae.org)2 TERMINOLOGY2.1 Basic Fastener Terminology2.1.1commercial fastener: manufactured to publishedconsensus standards and stocked by
40、manufacturers ordistributors.2.1.2compression fastener: a fastener whose primary functionis to resist compressive forces.2.1.3endurance limit or endurance strength: the maximum alter-nating stress that a fastener can withstand for a specifiednumber of stress cycles without failure.2.1.4headed fasten
41、er: a fastener having one end enlarged orformed.2.1.5headless fastener: a fastener, either threaded orunthreaded, that does not have either end enlarged.2.1.6high-strength fastener: a fastener having high tensile andshear strengths attained through combinations ofmaterials, work-hardening, and heat
42、treatment. Thesefasteners usually have a tensile strength in excess of120,000 psi.ASME B18.12-20122.1.7lockpins and collars: a headed and externally groovedmechanical device designed for insertion through holesin assembled parts. A cylindrical collar is swaged intothe external groove as the lock pin
43、 is hydraulically ten-sioned. Collars are either smooth bored or may containa fit-tab. An optional flange provides a built-in washer.2.1.8mechanical properties: identify the reaction of a fastenerto applied loads. Rarely are the mechanical propertiesof the fastener those of the raw material from whi
44、ch itwas made. Properties such as tensile and yield strengths,hardness, and ductility will vary widely, dependingupon choice of manufacturing methods and metallurgi-cal treatments.2.1.9modified standard: a part that is standard with one ormore of its features or characteristics slightly changed.Such
45、 a part that is normally ordered to a customersprint is used by that customer in a particular application,but the part is such that any interested manufacturercan produce it.2.1.10nonstandard fastener or special fastener: a fastener that dif-fers in size, length, configuration, material, or finishfr
46、om established and published standards.2.1.11physical properties: inherent in the raw material andremain unchanged or with only slight alteration in thefastener following manufacture. Such properties aredensity, thermal conductivity, and magneticsusceptibility.2.1.12Part Identifying Number (PIN): a
47、21-character code thatidentifies an ASME B18 manufactured product by spe-cific characteristic fields, such as fastener family identifi-cation, B18 standard identification, fastener style or type,thread series, nominal diameter, nominal length ordimensional/other characteristics, material and treat-m
48、ent, plating, coating, and passivation and special fea-tures relevant to the fastener product.2.1.13precision fastener: manufactured to close dimensional andgeometric tolerances.2.1.14proof load: a tensile load that the fastener must supportwithout evidence of permanent deformation. Proof loadis an
49、absolute value, not a maximum or minimum value.For most carbon or alloy steel fastener strength gradesor property classes, proof loads are established atapproximately 90% to 93% of the expected minimumyield strength. Proof loads are frequently used as designvalues in joint analysis and fastener selection.22.1.15proof test: a form of tensile test where the maximumload applied is the proof load value in the applicablespecification.2.1.16fastener quality: the accuracy of manufacture of the fas-tener such that it conforms to its specified tolerances,limits, and requirements.2.1.17a
