EN 1666

| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | BRITISH STANDARD BS EN 1666:1998 The European Standard EN 1666:1997 has the status of a British Standard ICS 21.060.20 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW Prevailing torque type hexagon nuts with flange (with non-metallic insert) with metric fine pitch thread (ISO 12125:1997, modified) This British Standard, having been prepared under the direction of the Engineering Sector Board, was published under the authority of the Standards Board and comes into effect on 15 April 1998  BSI 1998 ISBN 0 580 29326 2 BS EN 1666:1998 Amendments issued since publication Amd. No. Date Text affected National foreword This British Standard is the English language version of EN 1666:1997. The UK participation in its preparation was entrusted by Technical Committee FME/9, Bolts, nuts and accessories, to Subcommittee FME/9/10, Male and female prevailing torque fasteners, which has the responsibility to: ± aid enquirers to understand the text; ± present to the responsible European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; ± monitor related international and European developments and promulgate them in the UK. A list of organizations represented on this subcommittee can be obtained on request to its secretary. Cross-references The British Standards which implement international or European publications referred to in this document may be found in the BSI Standards Catalogue under the section entitled ªInternational Standards Correspondence Indexº, or by using the ªFindº facility of the BSI Standards Electronic Catalogue. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. WARNING The United Kingdom, as a member of CEN, is obliged to publish EN 1666:1997 as a British Standard. However, attention is drawn to the fact that during the development of this European Standard the United Kingdom has consistently voted against its approval as a European Standard. The UK believes that the corresponding ISO Standard, ISO 12125:1997 should have been implemented as the European Standard. As far as the UK is concerned, it is dangerous and not acceptable to have a separate European Standard that differs from the corresponding ISO Standard by the across flats dimension for one size of fastener, all other requirements being identical between the two standards concerned. As part of BSI's duty of care, we draw attention of users of this standard to our concerns that M10 nuts to this standard differ from similar fasteners conforming to ISO 12125:1997 in the across flats dimension only. This is 16 mm in the European Standard and 15 mm in the ISO. BSI will assume no liability whatsoever for the failure on the part of any user of this standard not to consider this aspect. Precautions are urged to ensure that comingling of M10 nuts to the two standards concerned is avoided. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, the EN title page, pages 2 to 6, an inside back cover and a back cover. CEN European Committee for Standardization Comite EuropeÂen de Normalisation EuropaÈisches Komitee fuÈ r Normung Central Secretariat: rue de Stassart 36, B-1050 Brussels  1997 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 1666:1997 E EUROPEAN STANDARD EN 1666 NORME EUROPE ENNE EUROPAÈ ISCHE NORM December 1997 ICS 21.060.20 Descriptors: Fasteners, nuts: fasteners, hexagonal nuts, flanged nuts, self locking nuts, metals, screw threads, dimensions, dimensional tolerances, characteristics, verification, designation English version Prevailing torque type hexagon nuts with flange (with non-metallic insert) with metric fine pitch thread (ISO 12125:1997, modified) Ecrous hexagonaux embase, autofreineÂs, (avec anneau non meÂtallique), aÁ filetage meÂtrique aÁ pas fin (ISO 12125:1997, modifieÂe) Sechskantmuttern mit Klemmteil und Flansch (mit nichtmetallischem Einsatz), und metrischem Feingewinde (ISO 12125:1997, modifiziert) This European Standard was approved by CEN on 1997-10-24. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the Central Secretariat or to any CEN member. This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the Central Secretariat has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. Page 2 EN 1666:1997  BSI 1998 Foreword This European Standard has been prepared by Technical Committee CEN/TC 185, Threaded and non-threaded mechanical fasteners and accessories, 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 by endorsement, at the latest by June 1998, and conflicting national standards shall be withdrawn at the latest by June 1998. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom. Endorsement notice The text of the International Standard ISO 12125:1997 was approved by CEN as a European Standard with agreed common modifications given as below. The dimensions of nuts correspond to those given in EN 1661 plus prevailing torque feature. Nuts according to this European Standard correspond to those specified in the International Standard ISO 12125 with the exception that the width across flats for M10 is 16 mm (instead of 15 mm). Page 3 EN 1666:1997  BSI 1998 1) Prevailing torque element, shape optional. 2) mw is the wrenching height; see note to Table 1. 3) u = 908 to 1208. 4) d = 158 to 258. 5) c is measured at dw min. 6) Edge contour optional. Figure 1 1 Scope This European Standard specifies the characteristics of prevailing torque type hexagon nuts with flange, with non-metallic annular insert and metric fine pitch thread with nominal thread diameters d from 8 mm up to and including 20 mm, in product grade A for d# 16 mm and product grade B for d > 16 mm and with property classes 6, 8 and 10. 2 Normative references This European Standard incorporates by dated or undated reference, provisions from other publications. These normative references are cited at the appropriate places in the text and the publications are listed hereafter. For dated references, subsequent amendments to or revisions of any of these publications apply to this European Standard only when incorporated in it by amendment or revision. For undated references the latest edition of the publication referred to applies. EN 493, Fasteners Ð Surface discontinuities Ð Nuts prEN ISO 2320, Prevailing torque type steel hexagon nuts Ð Mechanical and performance properties (ISO/DIS 2320:1994) prEN ISO 4042, Fasteners Ð Electroplated coatings (ISO/DIS 4042:1996) prEN ISO 4759-1, Tolerances for fasteners Ð Part 1: Bolts, screws, studs and nuts Ð Product grades A, B and C (ISO/DIS 4759-1:1997) ISO 724, ISO general purpose metric screw threads Ð Basic dimensions ISO 965-2, ISO general purpose metric screw threads Ð Tolerances Ð Part 2: Limits of sizes for general purpose bolt and nut threads Ð Medium quality ISO 3269, Fasteners Ð Acceptance inspection ISO 8992, Fasteners Ð General requirements for bolts, screws, studs and nuts 3 Dimensions Dimensions shall be in accordance with Figure 1 and Table 1. NOTE Symbols and designations of dimensions are specified in EN 20225. Page 4 EN 1666:1997  BSI 1998 Table 1 Dimensions in millimetres Thread, d 3 P2) M8 3 1 M10 3 1 M10 3 1,25 M123 1,5 M12 3 1,25 (M14 3 1,5)1) M16 3 1,5 M20 3 1,5 c min. 1,2 1,5 1,8 2,1 2,4 3 da min. 8,0 10,0 12 14,0 16,0 20,0 max. 8,75 10,8 13 15,1 17,3 21,6 dc max. 17,9 21,8 26 29,9 34,5 42,8 dw min. 15,8 19,6 23,8 27,6 31,9 39,9 e min. 14,38 17,77 20,03 23,36 26,75 32,95 h min. 11,1 13,5 16,1 18,2 20,3 24,8 max. 10,4 12,8 15,4 16,9 19,0 22,7 m3) min. 7,6 9,6 11,6 13,3 15,3 18,7 mw min. 4,6 5,9 6,8 7,7 8,9 10,7 s max. 13,00 16,00 18,00 21,00 24,00 30,00 min. 12,73 15,73 17,73 20,67 23,67 29,16 r4) max. 0,48 0,6 0,72 0,88 0,96 1,2 1) The size in brackets should be avoided if possible. 2) P is the pitch of the thread. 3) Minimum thread height. 4) Radius r applies both at the corners and the flats of the hexagon. NOTE If the product passes the gauging given in annex A, the requirements for dimensions e, c and mw are satisfied. Page 5 EN 1666:1997  BSI 1998 4 Requirements and reference European or International Standards The requirements given in Table 2 apply. If, in special cases, specifications other than those listed in this European Standard are required, they shall be selected from existing European or International Standards, for example ISO 724, ISO 965-2, prEN ISO 2320, prEN ISO 4759-1. 5 Designation EXAMPLE: Designation of a prevailing torque type hexagon nut with flange, with non-metallic insert, thread M12 3 1,5 and property class 8: Hexagon nut EN 1666 ± M12 3 1,5 ± 8 Table 2 Material Nut body Steel Insert For example, polyamid General requirements International Standard ISO 8992 Thread Tolerance 6H International Standards ISO 724, ISO 965-2 Property class 6 8 10 Mechanical and Style decisive for d # 16 mm d > 16 mm performance properties mechanical properties1) style 1 style 2 style 1 style 2 European Standard prEN ISO 2320 Tolerances Product grade For d# 16 mm: A For d > 16 mm: B European Standard prEN ISO 4759-1 As processed Requirements for electroplated coatings are covered in prEN ISO 4042. Finish If different electroplating requirements are desired or if requirements are needed for other finishes, they should be negotiated between customer and supplier. Limits for surface discontinuities are covered in EN 493. Acceptability For acceptance inspection ISO 3269 applies. 1) Based on the thread height (dimension mmin) nuts to this standard are of style 2. However, since for style 2 prEN ISO 2320 does not specify mechanical properties for all property classes and sizes as specified in this standard, in some cases nuts have to be tested according to style 1. Page 6 EN 1666:1997  BSI 1998 Annex A (normative) Gauging of hexagon nuts with flange A.1 Recommended method for gauging of hexagon (see Figure A.1 and Table A.1) The nut shall be gauged using two plain ring gauges, A and B, to demonstrate the coincidental acceptability of hexagon height, wrenching height, corner fill and width across corners. Gauge A shall be placed over the hexagon and shall be seated on the flange. Gauge B shall be placed on the top of the nut normal to the nut axis. The two gauges shall not be in contact. A.2 Recommended method for gauging of flange (see Figure A.1 and Table A.1) Gauge C is a flat feeler or ring gauge. It is used to prove that the flange thickness at the junction of the gauge with the hexagon portion is equal to or greater than specified values. The acceptance criterion is that gauge C will fit under gauge A without contact when the nut is seated on a flat plate. 1 Gauge A 2 Gauge B 3 Gauge C NOTE Wa, min = etheoretical Wb, max = emin 2 0,01 mm Ta, max = mw, min Figure A.1 Table A.1 Dimensions in millimetres Nominal thread diameter Gauge A Gauge B Gauge C Wa Ta Wb Tb Wc Tc d max. min. max. min. max. min. min. min. max. min. 8 15,02 15,01 4,60 4,59 14,37 14,36 4 20 1,31 1,30 10 18,49 18,48 5,90 5,89 17,76 17,75 5 24 1,65 1,64 12 20,79 20,78 6,0 6,79 20,02 20,01 5 29 2,20 2,19 14 24,26 24,25 7,70 7,69 23,35 23,34 6 32,5 2,55 2,54 16 27,72 27,71 8,90 8,89 26,74 26,73 6 37 2,96 2,95 20 34,65 34,64 10,70 10,69 32,94 32,93 6 45 3,70 3,69 blank BSI 389 Chiswick High Road London W4 4AL | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | BSI Ð British Standards Institution BSI is the independent national body responsible for preparing British Standards. 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