1、BRITISH STANDARD AEROSPACE SERIES BS EN 3721:1995 Nuts, bihexagonal, self-locking, deep counterbored, in heat resisting steel FE-PA92HT (A286), MoS 2coated Classification: 1100MPa (at ambient temperature)/425 C The European Standard EN3721:1995 has the status of a BritishStandardBSEN3721:1995 This B
2、ritishStandard, having been prepared under the directionof the Engineering SectorBoard, was published underthe authority oftheStandards Board and comes into effect on 15November1995 BSI 12-1999 The following BSI references relate to the work on this standard: Committee reference ACE/12 Draft for com
3、ment91/76462 DC ISBN 0 580 24492 X Committees responsible for this BritishStandard The preparation of this BritishStandard was entrusted to Technical Committee ACE/12, Aerospace fasteners and fastening systems, upon which the following bodies were represented: Association of Electronics, Telecommuni
4、cations and Business Equipment Industries British Industrial Fasteners Federation Ministry of Defence Society of British Aerospace Companies Ltd. Amendments issued since publication Amd. No. Date CommentsBSEN3721:1995 BSI 12-1999 i Contents Page Committees responsible Inside front cover National for
5、eword ii Foreword 2 1 Scope 3 2 Normative references 3 3 Required characteristics 3 4 Designation 5 5 Marking 5 6 Technical specification 5 Figure 1 4 Table 1 4 List of references Inside back coverBSEN3721:1995 ii BSI 12-1999 National foreword This BritishStandard has been prepared by Technical Comm
6、ittee ACE/12 and is the English language version of EN3721:1995 Aerospace series Nuts, bihexagonal, self-locking, deep counterbored, in heat resisting steel, FE-PA92HT (A286), MoS 2coated Classification:1100MPa (at ambient temperature)/425 C, published by the European Committee for Standardization (
7、CEN). EN3721:1995 was produced as a result of international discussions in which the United Kingdom took an active part. Cross-reference There are no BritishStandards corresponding to the European Standards referred to in the text. A British Standard does not purport to include all the necessary pro
8、visions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Publication referred to Corresponding BritishStandard ISO5855-2:1988 BS6293 Aerospace. MJ threads Part2:1994
9、Limit dimensions for bolts and nuts Summary of pages This document comprises a front cover, an inside front cover, pagesi andii, theEN title page, pages2 to6, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This wil
10、l be indicated in the amendment table on the inside front cover.EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN3721 July1995 ICS 49.040.20 Descriptors: Aircraft industry, hexagonal nut, self-locking nut, heat resistant steel, coating, classification, dimension, dimensional tolerance, designatio
11、n English version Aerospace series Nuts, bihexagonal, self-locking, deep counterbored, in heat resisting steel, FE-PA92HT (A286), MoS 2coated Classification:1100MPa (at ambient temperature)/425 C Srie arospatiale crous bihexagonaux, freinage interne, chambrs, en acier rsistant chaud FE-PA92HT (A286)
12、, revtus MoS 2 Classification:1100MPa ( temprature ambiante)/425 C Luft- und Raumfahrt Zwlfkantmuttern, selbstsichernd, mit zylindrischer Aussenkung, aus hochwarmfestem Stahl FE-PA92HT (A286), MoS 2beschichtet Klasse:1100MPa (bei Raumtemperatur)/425 C This European Standard was approved by CEN on199
13、5-03-18. 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 obta
14、ined 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 Secr
15、etariat has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and UnitedKingdom. CEN European Committee
16、 for Standardization Comit Europen de Normalisation Europisches Komitee fr Normung Central Secretariat: rue de Stassart 36, B-1050 Brussels 1995 Copyright reserved to CEN members Ref. No. EN3721:1995 EEN3721:1995 BSI 12-1999 2 Foreword This European Standard has been prepared by the European Associa
17、tion of Aerospace Manufacturers (AECMA). After inquiries and votes carried out in accordance with the rules of this Association, this standard has successively received the approval of the National Associations and the Official Services of the member countries of AECMA, prior to its presentation to
18、CEN. This European Standard shall be given the status of a national standard, either by the publication of anidentical text, or by endorsement, at the latest by January1996, and conflicting national standards shall be withdrawn at the latest by January1996. According to the CEN/CENELEC Internal Regu
19、lations, the following countries are bound to implement this European Standard: Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom.EN3721:1995 BSI 12-1999 3 1 Scope This st
20、andard specifies the characteristics of self-locking bihexagonal nuts with deep counterbore, in FE-PA92HT, MoS 2coated, for aerospace applications. Classification:1100MPa 1) /425 C 2) 2 Normative references This European Standard incorporates by dated or undated reference provisions from other publi
21、cations. 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 revisio
22、n. For undated references the latest edition of the publication referred to applies. ISO4095, Fasteners for aerospace construction Bi-hexagonal wrenching configuration. ISO5855-2, Aerospace MJ threads Part2: Limit dimensions for bolts and nuts. EN2399, Heat resisting steel FE-PA92-HT R m U 900MPa Ba
23、rs for forged bolts Dk 25mm Aerospace series 3) . EN2424, Aerospace series Marking of aerospace products. EN2491, Aerospace series Molybdenum disulphide dry lubricants Coating methods 4) . EN3639, Aerospace series Heat resisting alloy FE-PA2601 Softened and cold worked Wire for forged fasteners Dk 1
24、5mm 900MPak R m k 1100MPa 5) . EN3752, Aerospace series Nuts, self-locking, MJ threads, in heat resisting steel FE-PA92HT (A286), MoS 2coated Classification:1100MPa (at ambient temperature)/425 C Technical specification 5) . 3 Required characteristics 3.1 Configuration Dimensions Tolerances Masses S
25、ee Figure 1 and Table 1. Dimensions and tolerances are in millimetres. They apply before MoS 2coating. 3.2 Materials EN2399 or EN3639 3.3 Surface treatment EN2491 1) Corresponds to the minimum tensile stress which the nut is able to withstand at ambient temperature without breaking or cracking when
26、tested with a bolt of a higher strength class. 2) Maximum test temperature of the parts 3) Published as AECMA Standard at the date of publication of this standard 4) In preparation at the date of publication of this standard 5) Published as AECMA Prestandard at the date of publication of this standa
27、rdEN3721:1995 4 BSI 12-1999 Table 1 Figure 1 Thread a E F H J K L M N T Y Z Mass kg/1000 parts Code Designation max. min. max. max. min. min. min. max. 0,2 050 MJ50,8-4H6H 5,8 5,2 7 11,5 9,1 8,3 5,7 2 9,4 4,5 0,1 0,2 2,87 060 MJ61-4H5H 7,1 6,3 8 12,9 10,6 9,8 5,95 2,3 10,3 4,75 3,98 070 MJ71-4H5H 8,
28、1 7,3 9 14,1 12,1 11,3 6,2 2,6 11,1 5 4,95 080 MJ81-4H5H 9,1 8,3 10 15,7 13,6 12,8 6,45 2,8 12,2 5,25 6 100 MJ101,25-4H5H 11,1 10,3 12 18,5 16,8 15,8 6,7 3,1 14,3 5,5 0,13 0,3 8,84 a In accordance with ISO5855-2. In the self-locking zone, the tolerances apply before forming out-of-round.EN3721:1995
29、BSI 12-1999 5 4 Designation EXAMPLE: NOTEIf necessary, the code19005 shall be placed between the description block and the identity block. 5 Marking EN2424, style A, as indicated on Figure 1. 6 Technical specification EN37526 blankBSEN3721:1995 BSI 12-1999 List of references See national foreword.BS
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