1、BS EN ISO2320:2008ICS 21.060.20NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBRITISH STANDARDPrevailing torquetype steel nuts Mechanicaland performanceproperties (ISO2320:2008)Copyright European Committee for Standardization Provided by IHS under license with CENNot for Resal
2、eNo reproduction or networking permitted without license from IHS-,-,-This British Standardwas published underthe authority of theStandards Policy andStrategy Committee on 32008 BSI 2008ISBN 978 0 580 58341 4Amendments/corrigenda issued since publicationDate CommentsBS EN ISO 2320:2008National forew
3、ordThis British Standard is the UK implementation of EN ISO 2320:2008. Itsupersedes BS EN ISO 2320:1998 which is withdrawn.The UK participation in its preparation was entrusted to TechnicalCommittee FME/9/1, Mechanical properties of fasteners.A list of organizations represented on this committee can
4、 be obtained onrequest to its secretary.This publication does not purport to include all the necessary provisionsof a contract. Users are responsible for its correct application.Compliance with a British Standard cannot confer immunityfrom legal obligations.1DecemberCopyright European Committee for
5、Standardization Provided by IHS under license with CENNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-EUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NORMEN ISO 2320November 2008ICS 21.060.20 Supersedes EN ISO 2320:1997 English VersionPrevailing torque type steel nuts -
6、 Mechanical and performanceproperties (ISO 2320:2008)crous autofreins en acier - Caractristiques mcaniqueset performances (ISO 2320:2008)Muttern aus Stahl mit Klemmteil - Mechanische undfunktionelle Eigenschaften (ISO 2320:2008)This European Standard was approved by CEN on 25 October 2008.CEN member
7、s are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this EuropeanStandard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such nationalstandards may be obtained on application t
8、o the CEN Management Centre or to any CEN member.This European Standard exists in three official versions (English, French, German). A version in any other language made by translationunder the responsibility of a CEN member into its own language and notified to the CEN Management Centre has the sam
9、e status as theofficial versions.CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland,France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,Roman
10、ia, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMIT EUROPEN DE NORMALISATIONEUROPISCHES KOMITEE FR NORMUNGManagement Centre: rue de Stassart, 36 B-1050 Brussels 2008 CEN All rights of exploitation in any form and by any means reservedworl
11、dwide for CEN national Members.Ref. No. EN ISO 2320:2008: ECopyright European Committee for Standardization Provided by IHS under license with CENNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-BS EN ISO 2320:2008EN ISO 2320:2008 (E) 3 Foreword This document (EN IS
12、O 2320:2008) has been prepared by Technical Committee ISO/TC 2 “Fasteners“ in collaboration with Technical Committee CEN/TC 185 “Fasteners” the secretariat of which is held by DIN. This European Standard shall be given the status of a national standard, either by publication of an identical text or
13、by endorsement, at the latest by May 2009, and conflicting national standards shall be withdrawn at the latest by May 2009. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN and/or CENELEC shall not be held responsible for ident
14、ifying any or all such patent rights. This document supersedes EN ISO 2320:1997. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denma
15、rk, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. Endorsement notice The text of ISO 2320:2008 has been approved
16、 by CEN as a EN ISO 2320:2008 without any modification. Copyright European Committee for Standardization Provided by IHS under license with CENNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-BS EN ISO 2320:2008ISO 2320:2008(E) ISO 2008 All rights reserved iiiConten
17、ts Page Foreword iv 1 Scope . 1 2 Normative references . 1 3 Terms and definitions. 2 4 Symbols . 2 5 Thread 3 6 Lubrication 3 7 Mechanical properties of prevailing torque type nuts 3 8 Performance requirements for prevailing torque properties . 3 9 Test method. 12 9.1 General. 12 9.2 Proof load tes
18、t. 12 9.3 Prevailing torque test . 12 Annex A (normative) Temperature resistance of prevailing torque non-metallic insert type nuts . 17 Annex B (informative) Basis for the evaluation of the total coefficient of friction, tot. 18 Bibliography . 19 Copyright European Committee for Standardization Pro
19、vided by IHS under license with CENNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-BS EN ISO 2320:2008ISO 2320:2008(E) iv ISO 2008 All rights reservedForeword ISO (the International Organization for Standardization) is a worldwide federation of national standards b
20、odies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizati
21、ons, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. International Standards are drafted in accordance with the rules given in the
22、 ISO/IEC Directives, Part 2. The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of t
23、he member bodies casting a vote. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO 2320 was prepared by Technical Committee ISO/TC 2, Fasteners, Su
24、bcommittee SC 1, Mechanical properties of fasteners. This fourth edition cancels and replaces the third edition (ISO 2320:1997), which has been technically revised. It also incorporates the Technical Corrigendum ISO 2320:1997/Cor.1:2006. Copyright European Committee for Standardization Provided by I
25、HS under license with CENNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-BS EN ISO 2320:2008INTERNATIONAL STANDARD ISO 2320:2008(E) ISO 2008 All rights reserved 1Prevailing torque type steel nuts Mechanical and performance properties 1 Scope This International Stan
26、dard specifies the mechanical and performance properties for prevailing torque type steel nuts when tested at an ambient temperature range of +10 C to +35 C. It includes a single test to determine the prevailing torque properties (performance properties) and/or the torque/clamp force properties. Thi
27、s International Standard applies to prevailing torque all metal type nuts and prevailing torque non-metallic insert type nuts: a) with triangular ISO thread according to ISO 68-1; b) with diameter/pitch combination according to ISO 261 and ISO 262; c) with coarse pitch thread M3 to M39 and mechanica
28、l properties according to ISO 898-2; d) with fine pitch thread M81 to M393 and mechanical properties according to ISO 898-6; e) within the temperature range of 50 C to +150 C for prevailing torque all metal type nuts; NOTE 1 See Clause 7, paragraph 3. f) within the temperature range of 50 C to +120
29、C for prevailing torque non-metallic insert type nuts. NOTE 2 See Clause 7, paragraph 4. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition
30、of the referenced document (including any amendments) applies. ISO 273:1979, Fasteners Clearance holes for bolts and screws ISO 898-1, Mechanical properties of fasteners made of carbon steel and alloy steel Part 1: Bolts, screws and studs ISO 898-2, Mechanical properties of fasteners Part 2: Nuts wi
31、th specified proof load values Coarse thread ISO 898-6, Mechanical properties of fasteners Part 6: Nuts with specified proof load values Fine pitch thread ISO 965-2, ISO general purpose metric screw threads Tolerances Part 2: Limits of sizes for general purpose external and internal screw threads Me
32、dium quality ISO 16047, Fasteners Torque/clamp force testing Copyright European Committee for Standardization Provided by IHS under license with CENNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-BS EN ISO 2320:2008ISO 2320:2008(E) 2 ISO 2008 All rights reserved3 T
33、erms and definitions For the purposes of this document, the terms and definitions given in ISO 16047 and the following apply. 3.1 prevailing torque type nut nut which is not free-running on a mating thread by virtue of a self-contained prevailing torque feature, and which provides a degree of resist
34、ance to rotation independent of clamping or compression forces 3.2 prevailing torque developed by the nut torque necessary to rotate the nut on its mating externally threaded component and with no axial force in the mating component 3.3 prevailing-on torque torque to rotate the nut on its mating ext
35、ernally threaded component with the torque measured while the nut is in motion and with no clamp force 3.4 prevailing-off torque torque to rotate after backing off the nut until the removal of the clamp force in the externally threaded component in the following 360 rotation of the nut 3.5 prevailin
36、g torque all metal type nut nut which has a one piece or a multiple piece metal construction and derives its prevailing torque characteristics from a controlled distortion of the nut thread and/or body or from metallic insert(s) 3.6 prevailing torque non-metallic insert type nut nut which has a mult
37、iple piece construction and derives its prevailing torque characteristics from insert(s) of non-metallic material located and retained in the nut 3.7 seating point point in the tightening process where clamp force first appears 4 Symbols For the purpose of this International Standard, the following
38、symbols apply together with those defined in ISO 16047. Symbol Designation d nominal diameter d4diameter of the hole of the fixture FPproof load F65lower load limit for the evaluation of the coefficient of total friction at 65 % of FPF75upper load limit for the evaluation of the coefficient of total
39、 friction at 75 % of FPF80test clamp force (shut-down force for the tightening process) at 80 % of FPP pitch of the thread TFvprevailing-on torque, in newton metres Copyright European Committee for Standardization Provided by IHS under license with CENNot for ResaleNo reproduction or networking perm
40、itted without license from IHS-,-,-BS EN ISO 2320:2008ISO 2320:2008(E) ISO 2008 All rights reserved 3TFdprevailing-off torque, in newton metres T65lower torque limit for the evaluation of the coefficient of total friction at F65T75upper torque limit for the evaluation of the coefficient of total fri
41、ction at F75T80test torque corresponding to 80 % of the proof load, in newton metres (see Tables 1 to 8) totcoefficient of total friction 5 Thread Threads for prevailing torque type nuts shall be in accordance with ISO 965-2 except for the prevailing torque feature: a) for prevailing torque non-meta
42、llic insert type nuts, the GO gauge shall be suitable for free installation (by hand) until it is seated against the prevailing torque feature; b) for prevailing torque all metal type nuts, the GO gauge shall be suitable for free installation (by hand) to one pitch at least. 6 Lubrication At the opt
43、ion of the manufacturer a lubricant may be applied to the manufacturing lot to fulfil the performance requirements. 7 Mechanical properties of prevailing torque type nuts The mechanical properties of prevailing torque type nuts shall conform to ISO 898-2 or ISO 898-6. With regard to proof load, the
44、test method specified in 9.2 shall apply. For prevailing torque all metal type nuts, users should consult an experienced fastener materials expert for temperatures outside the range of 50 C to +150 C to determine appropriate choices for a given application. For prevailing torque non-metallic insert
45、type nuts, use at or near the temperature limits of 50 C and +120 C may reduce the prevailing torque capability and may require the use of an adequate non-metallic material. Users should consult an experienced fastener materials expert for temperatures outside the range of 50 C to +120 C to determin
46、e appropriate choices for a given application. 8 Performance requirements for prevailing torque properties The prevailing-on torque shall not exceed the value specified for the applicable nut in Tables 1 to 8. The prevailing-off torque shall exceed the value specified for the applicable nut in Table
47、s 1 to 8. For delivery inspection, the 1st installation/removal test applies, unless otherwise agreed. For initial type testing and in case of dispute, a 5th removal test shall also be applied unless otherwise agreed. Prevailing torque performance decreases as a function of the number of reuses; the
48、 consumer should take into consideration the consequences of the decreased performance before any reuse of the nut. By request of the customer, a temperature resistance test for prevailing torque non-metallic insert type nuts as given in Annex A may be carried out. Paragraphs 3 and 4 of Clause 7 also apply to performance requirements. Copyright European Committee for Standardization Provided by IHS under license with CENNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-BS EN ISO 2320:2008ISO 2320:2008(E) 4 ISO 2008
