1、BRITISH STANDARD AEROSPACE SERIES BS A321:1997 ISO12274: 1997 Aerospace Nuts,anchor, self-locking, floating, self-aligning, single lug, with MJ threads, classifications: 900MPa(at ambient temperature)/235 C, 900MPa (at ambient temperature)/315 C and900MPa (atambient temperature)/425 C Dimensions ICS
2、49.030.30BSA321:1997 This British Standard, having been prepared under the directionof the Engineering SectorBoard, was published underthe authority of the Standards Board and comesintoeffect on 15 October1997 BSI09-1999 ISBN 0 580 28732 7 National foreword This British Standard reproduces verbatim
3、ISO12274:1997 and implements it as the UK national standard. The UK participation in its preparation was entrusted by Technical Committee ACE/12, Aerospace fasteners and fastening systems, to Subcommittee ACE/12/1, Aerospace fasteners and fastening systems (international), which has the responsibili
4、ty to: aid enquirers to understand the text; present to the responsible international/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
5、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 “International
6、 Standards Correspondence Index”, or by using the “Find” 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. Compliance with a British
7、Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, theISO title page, pagesii toiv, pages1 and 2 and a back cover. This standard has been updated (see copyright date) and may have had amen
8、dments incorporated. This will be indicated in the amendment table on the inside front cover. Amendments issued since publication Amd. No. Date CommentsBSA321:1997 BSI 09-1999 i Contents Page National foreword Inside front cover Foreword iii Text of ISO 12274 1ii blankBSA321:1997 ii BSI 09-1999 Cont
9、ents Page Foreword iii Introduction 1 1 Scope 1 2 Normative references 1 3 Configuration and dimensions 1 Figure 1 2 Table 1 2 Descriptors: Aircraft industry, fasteners, MJ threads, nuts (fasteners) anchor nuts, self-locking nuts, floating nuts, classification, form specifications, dimensions.BSA321
10、:1997 BSI 09-1999 iii Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a
11、 subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commissio
12、n (IEC) on all matters of electrotechnical standardization. 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 least75% of the member bodies casting a vote. International S
13、tandard ISO12274 was prepared by Technical Committee ISO/TC20, Aircarft and space vehicles, Subcommittee SC4, Aerospace fastenersystems.iv blankBSA321:1997 BSI 09-1999 1 Introduction The dimensions specified in this International Standard have been determined to satisfy the requirements of the procu
14、rement specification of ISO5858. 1 Scope This International Standard specifies the dimensions of floating, self-aligning, single lug anchor nuts, with MJ threads and a self-locking feature achieved by forming the upper portion out-of-round, of classifications:900MPa 1) /235 C 2) , 900MPa 1) /315 C 2
15、) and900MPa 1) /425 C 2) . This International Standard is only applicable for the compilation of aerospace product standards. 2 Normative references The following standards contain provisions which, through reference in this text, constitute provisions of this International Standard. At the time of
16、publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. Members of IEC and ISO maintain r
17、egisters of currently valid International Standards. ISO5855-2:1988, Aerospace MJ threads Part2: Limit dimensions for bolts and nuts. ISO5858:1991, Aerospace Self-locking nuts with maximum operating temperature less than or equal to425 C Procurement specification. ISO8788:1987, Aerospace Fasteners T
18、olerances of form and position for nuts. 3 Configuration and dimensions See Figure 1 and Table 1. Dimensions and tolerances are expressed in millimetres. They apply after any surface coating(s) but before the application of any lubricant. 1) Corresponds to the minimum tensile stress which the nut is
19、 able to withstand at ambient temperature without breaking or cracking when tested with a bolt of a higher strength class. 2) Maximum temperature that the nut is able to withstand, without permanent alteration to its original characteristics, after ambient temperature has been restored. The maximum
20、temperature is conditioned by the material or by the surface treatment.BSA321:1997 2 BSI 09-1999 Table 1 NOTETolerances of form and position shall conform to those specified in ISO8788. 1) These values, in micrometers, apply before any surface coating(s) is (are) applied. The values do not apply to
21、threads and sheared edges, the surface texture of which will be as achieved by the usual manufacturing methods. 2) Axial misalignment:8 minimum in any direction from central position Figure 1 Diameter code Thread a E F H K L M N b P R S T Radial floating Z min. max. max. max. max. min. max. min. 050
22、 MJ50,84H6H 8,75 12,7 7,9 3,5 15,2 26,7 8,3 0,9 6,7 3 2,5 7,2 0,7 060 MJ614H5H 4 17 31,7 10,2 7,6 7,8 0,75 080 MJ814H5H 5 20,5 33,3 11,8 1,1 11 3,5 3 8,4 a In accordance with ISO5855-2. In the self-locking zone, the tolerances apply before forming out-of-round. b Is applicable at the rivet hole loca
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