BS A 342-1999 Nuts plain or slotted (castellated) - Procurement specification《普通或带槽(槽顶)螺母 采购规格》.pdf

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1、BRITISH STANDARD AEROSPACE SERIES BS A 342:1999 ISO 9139:1998 Nuts, plain or slotted (castellated) Procurement specification ICS 49.030.30BSA342:1999 This British Standard, having been prepared under the directionof the Engineering SectorCommittee, was publishedunder the authority ofthe Standards Co

2、mmittee andcomes into effect on 15 March 1999 BSI 05-1999 ISBN 0 580 32260 2 National foreword This British Standard reproduces verbatim ISO9139:1998 and implements it as the UK national standard. The UK participation in its preparation was entrusted by Technical Committee ACE/12, Aerospace fastener

3、s and fastening systems, to Subcommittee ACE/12/1, Aerospace fasteners and fastening systems (International), which has the responsibility to: aid enquirers to understand the text; present to the responsible international/European committee any enquiries on the interpretation, or proposals for chang

4、e, 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

5、European publications referred to in this document may be found in the BSI Standards Catalogue under the section entitled “International 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

6、necessary provisions 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. Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, t

7、heISO title page, pages ii to iv, pages 1 to 14 and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover. Amendments issued since publication Amd. No. Date CommentsBSA342:19

8、99 BSI 05-1999 i Contents Page National foreword Inside front cover Foreword iii Text of ISO9139 1ii blankBSA342:1999 ii BSI 05-1999 Contents Page Foreword iii 1 Scope 1 2 Normative references 1 3 Terms and definitions 1 4 Quality assurance 2 4.1 General 2 4.1.1 Approval of manufacturers 2 4.1.2 Qua

9、lification of nuts 2 4.1.3 Production acceptance of nuts 2 4.2 Qualification inspection and test conditions 3 4.3 Production acceptance inspection and test conditions 3 4.4 Use of “Statistical process control (SPC)” 3 5 Technical requirements 3 Annex A (normative) Types of permissible surface discon

10、tinuity 14 Annex B (informative) Cross-sectional area formula 14 Figure A.1 14 Table 1 Technical requirements 4 Table 2 Summary of qualification and production acceptance inspections and tests 8 Table 3 Loads to be applied in the80% axial load test 9 Table 4 Loads to be applied in the100% axial load

11、 test 10 Table 5 Torques to be applied in the stress embrittlement test 11 Table 6 Classification of visual and dimensional inspections 11 Table 7 Sampling plans for visual and dimensional inspections 12 Table 8 Sampling plans for the inspection of mechanical and metallurgical characteristics 12 Tab

12、le 9 Maximum depth of permissible surface discontinuities 13 Descriptors: Aircraft industry, fasteners, MJ threads, nuts (fasteners), specifications, mechanical properties, quality assurance, marking, metric system.BSA342:1999 BSI 05-1999 iii Foreword ISO (the International Organization for Standard

13、ization) 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 subject for which a technical committee has been established has the right to

14、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 Commission (IEC) on all matters of electrotechnical standardization. International Stand

15、ards are drafted in accordance with the rules given in the ISO/IEC Directives, Part3. 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 casti

16、ng a vote. International Standard ISO9139 was prepared by Technical Committee ISO/TC20, Aircraft and space vehicles, Subcommittee SC4, Aerospace fastener systems. Annex A forms an integral part of this International Standard. Annex B is for information only.iv blankBSA342:1999 BSI 05-1999 1 1 Scope

17、This International Standard specifies the required characteristics for metric plain or slotted (castellated) nuts, with MJ threads according to ISO5855-2, for use in aerospace construction. It is applicable to nuts as defined above, provided that reference is made to this International Standard in t

18、he relevant definition document. 2 Normative references The following normative documents contain provisions which, through reference in this text, constitute provisions of this International Standard. For dated references, subsequent amendments to, or revisions of, any of these publications do not

19、apply. However, parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated references, the latest edition of the normative document referred to applies. Members

20、of ISO and IEC maintain registers of currently valid International Standards. ISO 1463:1982, Metallic and oxide coatings Measurement of coating thickness Microscopical method. ISO 2859-1:1989, Sampling procedures for inspection by attributes Part1: Sampling plans indexed by acceptable quality level

21、(AQL) for lot-by-lot inspection. ISO 3452:1984, Non-destructive testing Penetrant inspection General principles. ISO 3887:1976, Steel, non-alloy and low-alloy Determination of depth of decarburization. ISO 4288:1996, Geometrical Product Specifications (GPS) Surface texture: Profile method Rules and

22、procedures for the assessment of surface texture. ISO 5855-2:1988, Aerospace MJ threads Limit dimensions for bolts and nuts. ISO 7870:1993, Control charts General guide and introduction. ISO 7966:1993, Acceptance control charts. ISO 8258:1991, Shewhart control charts. ISO 8788:1987, Aerospace Fasten

23、ers Tolerances of form and position for nuts. ISO 9002:1994, Quality systems Model for quality assurance in production, installation and servicing. ISO 9003:1994, Quality systems Model for quality assurance in final inspection and test. ISO 9140:1998, Aerospace Plain or slotted (castellated) nuts Te

24、st methods. ISO 9227:1990, Corrosion tests in artificial atmospheres Salt spray tests. ISO/TR 13425:1995, Guide for selection of statistical methods in standardization and specification. 3 Terms and definitions For the purposes of this International Standard, the following terms and definitions appl

25、y. 3.1 definition document document specifying all the requirements for nuts, i.e.: metallurgical; geometrical and dimensional; functional (strength and temperature classes) NOTEThe definition document may be an International Standard, a national standard, an in-house standard or drawing. 3.2 finish

26、ed nut nut ready for use, inclusive of any possible treatments and/or surface coatings, as specified in the definition document 3.3 batch definite quantity of some commodity manufactured or produced under conditions which are presumed to be uniform NOTEFor the purposes of this International Standard

27、, a batch is a quantity of finished nuts, of the same type and same diameter, produced from a material obtained from the same melt, manufactured in the course of the same production cycle, following the same manufacturing route and having undergone all the relevant heat treatments and surface treatm

28、ents. 3.4 crack rupture in the material which may extend in any direction and which may be intercrystalline or transcrystalline in character 3.5 seem open surface defect resulting from extension of the metal 3.6 lap folding over of unwelded metal that can arise when the material is formed (drawing)

29、or in the finished product (pressing or forging) 3.7 inclusions non-metallic particles originating from the material manufacturing process NOTEThese particles may be isolated or arranged in strings.BSA342:1999 2 BSI 05-1999 3.8 critical defect defect that, according to judgement and experience, is l

30、ikely to result in hazardous or unsafe conditions for individuals using, maintaining, or depending upon the considered product, or that is likely to prevent performance of the function of a major end item 3.9 major defect defect other than critical, that is likely to result in a failure or to reduce

31、 materially the usability of the considered product for its intended purpose 3.10 minor defect defect that is not likely to reduce materially the usability of the considered product for its intended purpose, or that is a departure from established specifications having little bearing on the effectiv

32、e use or operation of this product 3.11 sampling plan plan according to which one or more samples are taken in order to obtain information and possibly reach a decision NOTEFor the purposes of this International Standard, each sampling plan specifies the number of nuts to be inspected as a function

33、of the size of the batch and the acceptance number number of defective items acceptable (Ac) 1) . 3.12 simple random sampling sampling of n items from a population of N items in such a way that all possible combinations of n items have the same probability of being chosen 3.13 acceptable quality lev

34、el AQL maximum percent defective (or the maximum number of defects per hundred units) that, for purposes of sampling inspection, can be considered satisfactory as a process average NOTEVariant: quality level which in a sampling plan corresponds to a specified but relatively high probability of accep

35、tance. 3.14 limiting quality LQ (sampling plan) quality level which corresponds to a specified and relatively low probability of acceptance NOTE 1It is the limiting lot quality characteristic that the consumer is willing to accept with a low probability that a lot of this quality would occur. NOTE 2

36、For the purposes of this International Standard, the limiting quality given in Table 7 corresponds to a consumers risk of10%. 4 Quality assurance 4.1 General 4.1.1 Approval of manufacturers The manufacturer shall conform to the quality assurance and approval procedures defined in ISO9003 for nuts of

37、 strength classes less than1550MPa and/or of temperature classes less than650C. The manufacturer shall conform to the quality assurance and approval procedures defined by ISO9002 for nuts of strength classes greater than or equal to1550MPa and/or of temperature classes greater than or equal to650C.

38、The purpose of these procedures is to ensure that a manufacturer has a quality system and the capability for continuous production of nuts complying with the specified quality requirements. Approval of the manufacturer shall be granted by the Certification Authorities, or their appointed representat

39、ive, who may be the prime contractor. 4.1.2 Qualification of nuts The purpose of qualification inspections and tests of nuts is to check that the design and manufacturing conditions of a nut allow it to satisfy the requirements of this International Standard. The qualification is applicable to nuts

40、of strength classes greater than or equal to1550MPa and/or of temperature classes greater than or equal to650C. It shall be granted by the Certification Authorities in the purchasers country, or their appointed representative, who may be the prime contractor. 4.1.3 Production acceptance of nuts The

41、purpose of production acceptance inspection and tests of a nut is to check, as simply as possible, using a method which is inexpensive but the most representative of the actual conditions of use, with the uncertainty inherent in statistical sampling, that the nuts satisfy the requirements of this In

42、ternational Standard. Production acceptance inspections and tests shall be carried out by the manufacturer, or under his responsibility. The manufacturer is responsible for the quality of the nuts manufactured. 1) Supplementary information taken from ISO 2859-1.BSA342:1999 BSI 05-1999 3 4.2 Qualific

43、ation inspection and test conditions Qualification inspections and tests (requirements, methods, numbers of nuts) are specified in Table 1. They shall be carried out on: each type and diameter of nut of strength classes greater than or equal to1550MPa and/or of temperature classes greater than or eq

44、ual to650C; 75 nuts selected from a single inspection lot by simple random sampling. The test programme may possibly be reduced, or qualification of a nut granted without inspection or testing; any such decision shall be based on the results obtained on similar types and diameters of nuts provided t

45、hat the design and manufacturing conditions are identical. The inspections and tests shall be repeated on any nut if the supplier or the manufacturing conditions have changed. Qualification inspections and tests are summarized in Table 2. 4.3 Production acceptance inspection and test conditions Prod

46、uction acceptance inspections and tests (requirements, methods, numbers of nuts) are specified in Table 1. They shall be carried out on each batch. Nuts from the batch to be tested shall be selected by simple random sampling. Each nut may be submitted to several inspections or tests. The nuts to be

47、subjected to destructive inspections or tests may be those on which non-destructive inspections or tests have been carried out. If a more stringent inspection is deemed necessary, all or part of the qualification inspections and tests may be performed during the production acceptance inspections and

48、 testing. This disposition applies to each nut, whatever its strength or temperature class. In this case, the number of nuts submitted to these inspections and tests is the same as that submitted for qualification inspections and tests. Batches declared unacceptable after the production acceptance r

49、equirements shall be submitted for re-inspection only after all the defective units have been removed and/or defects have been corrected. In this case, the attribute(s) which caused the rejection shall be verified using a sample of twice the normal size with the same number of detective items acceptable. Production acceptance inspections and tests are summarized in Table 2. 4.4 Use of “Statistical process control (SPC)” Where a characteristic is obtained by a controlled statistical process, the manufa