1、BRITISH STANDARD AEROSPACE SERIES BS A 343: 1999 ISO 9140:1998 Nuts, plain or slotted (castellated) Test methods ICS 49.030.30BSA 343:1999 This British Standard, having been prepared under the directionof the Engineering SectorCommittee, was publishedunder the authorityofthe Standards Committee and
2、comes into effect on 15April1999 BSI 02-2000 ISBN 0 580 32261 0 National foreword This British Standard reproduces verbatim ISO9140:1998 and implements it as the UK national standard. The UK participation in its preparation was entrusted by Technical Committee ACE/12, Aerospace fasteners and fasteni
3、ng 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 change, and keep t
4、he 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 publ
5、ications 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 necessary pro
6、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. Summary of pages This document comprises a front cover, an inside front cover, pagesi andii, theISO title pag
7、e, pagesii toiv, pages1 to4 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 CommentsBSA 343:1999 BSI 02-2000 i Co
8、ntents Page National foreword Inside front cover Foreword iii Text of ISO 9140 1ii blankBSA 343:1999 ii BSI 02-2000 Contents Page Foreword iii 1 Scope 1 2 Normative references 1 3 Inspections and tests 1 Figure 1 2 Figure 2 3 Figure 3 4 Table 1 Pitch diameter of the mandrel of the bearing surface sq
9、uareness test 2 Descriptors: Aircraft industry, fasteners, MJ threads, nuts (fasteners), tests, hardness tests, mechanical tests, metric system.BSA 343:1999 BSI 02-2000 iii Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO m
10、ember 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 organizations, governm
11、ental 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 ISO/IEC Dir
12、ectives, 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 casting a vote. International Standard ISO9140 was prepared by Technical Co
13、mmittee ISO/TC20, Aircraft and space vehicles, Subcommittee SC4, Aerospace fastener systems.iv blankBSA 343:1999 BSI 02-2000 1 1 Scope This International Standard specifies test methods for metric plain or slotted (castellated) nuts, with MJ threads in accordance with ISO5855-2, for use in aerospace
14、 construction. It describes the test device and the method for each test. It is applicable to nuts as defined above, provided that the relevant documents (product standard, definition document, procurement specification, etc.) refer to this International Standard. This International Standard is to b
15、e used in conjunction with ISO9139 or any other similar 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,
16、any of these publications do not 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 docum
17、ent referred to applies. Members of ISO and IEC maintain registers of currently valid International Standards. ISO 691:1997, Assembly tools for screws and nuts Wrench and socket openings Tolerances for general use. ISO 1024:1989, Metallic materials Hardness test Rockwell superficial test (scales 15N
18、, 30N, 45N, 15T, 30T and 45T). ISO 5855-2:1988, Aerospace MJ threads Limit dimensions for bolts and nuts. ISO 6507-1:1997, Metallic materials Vickers test hardness Part 1: Test method. ISO 6508:1986, Metallic materials Hardness test Rockwell test (scales A B C D E F G H K). ISO 9139:1998, Aerospace
19、Nuts, plain or slotted (castellated) Procurement specification. 3 Inspections and tests 3.1 Hardness test 3.1.1 Procedure The procedure is a function of the nut configuration and of the available apparatus. The authorized procedures are as follows: Rockwell hardness, in accordance with ISO6508; Vick
20、ers hardness HV5 to HV100, in accordance with ISO6507-1; Rockwell superficial hardness, in accordance with ISO1024; microhardness. 3.1.2 Method This test shall be carried out at ambient temperature. The measurement shall be taken on the bearing surface or on one of the flats. Should this not be poss
21、ible, carry out this test on a cut section after moulding the nut into a thermosetting resin. Remove all possible coating (protection, lubrication, paint, etc.) in the measurement zone. True up the bearing surface to obtain the required relationship. These two operations shall not generate any heat
22、liable to modify the characteristics of the material constituting the nut to be tested. Carry out the test and then check conformity with the requirements of the dimensional standard or of the definition document. Nuts subjected to this test shall not be reused. 3.2 Bearing surface squareness test 3
23、.2.1 Test device The test device is illustrated inFigure 1. The test device includes the following elements: a) a threaded mandrel with an end in accordance with ISO5855-2, except for the pitch diameter which shall be in accordance with the values specified inTable 1; b) a collar sliding on the plai
24、n portion of the threaded mandrel the external diameter B of which shall be at least equal to the across flat dimension of the nut to be tested; c) a feeler gauge the thickness of which shall be equal to the permissible out-of-squareness specified in the product standard, in the definition document
25、or the procurement specification.BSA 343:1999 2 BSI 02-2000 Table 1 Pitch diameter of the mandrel ofthebearing surface squareness test 3.2.2 Method The test shall be carried out at ambient temperature. Manually screw the nut to be tested onto the mandrel until the thread is fully engaged. Move the c
26、ollar into contact with the nut. Evaluate the out-of-squareness by means of the feeler gauge then check conformity with the requirements of the product standard, or the definition document or the procurement specification. 3.3 Axial load test 3.3.1 Test device The test device is illustrated inFigure
27、 2. The test device includes the following elements: a) a bearing plate made of steel, heat-treated to HRCW 40; b) a bolt with the following characteristics; 1) threads: in accordance with ISO5855-2, 2) tensile strength class: greater than that of the nut to be tested, 3) material and coating: no sp
28、ecific requirement. Figure 1 Dimensions in millimetres Thread d 2 3 0,5 2,662 3,5 0,6 3,096 4 0,7 3,53 5 0,8 4,464 6 1 5,333 7 1 6,333 8 1 7,332 10 1,25 9,169 12 1,25 11,167 14 1,5 13,003 16 1,5 15,002 18 1,5 17,001 20 1,5 19 22 1,5 20,999 24 2 22,673 27 2 25,672 30 2 28,67 33 2 31,67 36 2 34,67 39
29、2 37,67 0 0,01BSA 343:1999 BSI 02-2000 3 3.3.2 Method The axial load is transmitted to the nut by the bolt, the nut resting on the bearing plate. 3.3.2.1 80% test This test shall be carried out at ambient temperature. Fit the bolt into the bearing plate then assemble the nut to be tested with a prot
30、rusion of two pitches minimum (including chamfer). Position the assembly on the tensile test machine. Apply the load slowly and progressively. Reduce the load slowly and progressively when the value stipulated in the procurement specification has been reached. Remove the assembly from the tensile te
31、st machine. Remove the nut, then submit it to a visual examination and, if necessary, to an examination at a magnification of 10 after sectioning, to check conformity with the requirements of the procurement specification. 3.3.2.2 100% test Proceed in the same way as for the80% test, with only the l
32、oad to be applied being different. Nuts subjected to this test shall not be reused. 3.4 Stress embrittlement test This test is only applicable to nuts heat-treated to HRCW 39 except when stated otherwise in the procurement specification or definition document. 3.4.1 Test device The test device is il
33、lustrated inFigure 3. The test device includes the following elements: a) a block with parallel faces made of steel, heat treated to HRCW 40; b) a bolt with the following characteristics: 1) threads: in accordance with ISO5855-2, 2) tensile strength class: greater than that of the nut to be tested,
34、3) material: cadmium-plated steel or steel with any other suitable coating with an equivalent coefficient of friction; c) a washer. 3.4.2 Method This test shall be carried out at ambient temperature without additional lubrication. Fit the bolt into the test block and hold it by the head. Fit the was
35、her, then the nut to be tested. Apply to the nut the seating torque specified in the procurement specification with a socket or closed wrench, the opening tolerance of which is in accordance with ISO691. Maintain the nut under axial tension during the length of time specified in the procurement spec
36、ification. After this time, dismantle the assembly, then submit the nut to a visual examination and, if necessary, to an examination at a magnification of 10 after sectioning, to check conformity with the requirements of the procurement specification. Nuts subjected to this test shall not be reused.
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