1、ASD STANDARD NORME ASD ASD NORM prEN 4621 Edition P 1 June 2008 PUBLISHED BY THE AEROSPACE AND DEFENCE INDUSTRIES ASSOCIATION OF EUROPE - STANDARDIZATIONAvenue de Tervuren, 270 - B-1150 Brussels - Tel. + 32 2 775 8126 - Fax. + 32 2 763 3565 - www.asd-stan.orgICS: 49.030.20 Descriptors: Aircraft indu
2、stry ENGLISH VERSION Aerospace series Inserts, MJ threads, self-locking, with self-broaching keys Technical specification Srie arospatiale Douilles filetes, filetage MJ, freinage interne, clavettes auto-brochantes Spcification technique Luft- und Raumfahrt Gewindeeinstze, MJ-Gewinden, selbstsichernd
3、, mit selbstrumenden Stiften Technische Lieferbedingungen This “Aerospace Series“ Prestandard has been drawn up under the responsibility of ASD-STAN (The AeroSpace and Defence Industries Association of Europe - Standardization). It is published for the needs of the European Aerospace Industry. It ha
4、s been technically approved by the experts of the concerned Domain following member comments. Subsequent to the publication of this Prestandard, the technical content shall not be changed to an extent that interchangeability is affected, physically or functionally, without re-identification of the s
5、tandard. After examination and review by users and formal agreement of ASD-STAN, it will be submitted as a draft European Standard (prEN) to CEN (European Committee for Standardization) for formal vote and transformation to full European Standard (EN). The CEN national members have then to implement
6、 the EN at national level by giving the EN the status of a national standard and by withdrawing any national standards conflicting with the EN. Edition approved for publication 30 June 2008 Comments should be sent within six months after the date of publication to ASD-STAN Mechanical Domain Copyrigh
7、t 2008 by ASD-STAN prEN 4621:20082 Contents Page Foreword2 1 Scope 3 2 Normative references 3 3 Terms and definitions .3 4 Quality assurance6 5 Requirements.6 Annex A (normative) Definition of test block17 Annex B (normative) Assembly for rotational resistance test18 Annex C (normative) Axial tensil
8、e strength test.19 Annex D (normative) Assembly for reusability test .21 Annex E (normative) “GO“ gauge for inspection of the position of the keys .23 Foreword This standard was reviewed by the Domain Technical Coordinator of ASD-STANs Mechanical Domain. After inquiries and votes carried out in acco
9、rdance with the rules of ASD-STAN defined in ASD-STANs General Process Manual, this standard has received approval for Publication. prEN 4621:20083 1 Scope This standard specifies the characteristics, qualification and acceptance requirements for self-locking inserts, self-broaching keys with MJ thr
10、eads, for aerospace applications. It is applicable whenever referenced. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced
11、 document (including any amendments) applies. ISO 2859-1, Sampling procedures for inspection by attributes Part 1: Sampling schemes indexed by acceptance quality limit (AQL) for lot-by-Iot inspection. ISO 3452, Non-destructive testing Penetrant inspection General principles. ISO 4288, Geometrical Pr
12、oduct Specifications (GPS) Surface texture: Profile method Rules and procedures for the assessment of surface texture ISO 5855-1, Aerospace MJ threads Part 1: General requirements. ISO 5855-2, Aerospace MJ threads Part 2: Limit dimensions for bolts and nuts. EN 2638, Aerospace series Aluminium alloy
13、 2024-T3 extruded bar and section 1,2 mm (a or D) 150 mm with coarse peripheral grain control. 1)EN 4619, Aerospace series Inserts, MJ threads, self-locking, with self-broaching keys Installation and removal procedure. 1)EN 4620, Aerospace series Inserts, MJ threads, self-locking, with self-broachin
14、g keys Design standard. 1)EN 9133, Aerospace series Quality management systems Qualification Procedure for Aerospace Standard Parts. ASTM E 112-96, Standard Test Methods for Determining Average Grain Size. 2)3 Terms and definitions For the purposes of this document, the following terms and definitio
15、ns apply. 3.1 batch quantity of finished parts, of the same type and same diameter, produced from the same 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 s
16、urface treatments 1) Published as ASD Prestandard at the date of publication of this standard. 2) Published by : American Society for Testing and Materials (ASTM), 1916, Race Street, Philadelphia, PA 19103, USA. prEN 4621:20084 3.2 Surface discontinuities 3.2.1 crack rupture in the material which ma
17、y extend in any direction and which may be intercrystalline or transcrystalline in character 3.2.2 seam open surface defect 3.2.3 lap surface defect caused by folding over metal fins or sharp corners and then rolling or forging them into the surface 3.2.4 inclusions metallic or non-metallic particle
18、s originating from the manufacturing process. These particles may be isolated or arranged in strings. 3.2.5 test temperature ambient temperature, unless otherwise specified 3.2.6 simple random sampling the taking of n items from a population of N items in such a way that all possible combinations of
19、 n items have the same probability of being chosen 3.2.7 critical defect a defect that, according to judgement and experience, is likely to result in hazardous or unsafe conditions for individuals using, maintaining, or depending upon the considered product, or that is likely to prevent performance
20、of the function of a major end item 3.2.8 major defect a defect other than critical, that is likely to result in a failure or to reduce materially the usability of the considered product for its intended purpose 3.2.9 minor defect a defect that is not likely to reduce materially the usability of the
21、 considered product for its intended purpose, or that is a departure from established specification having little bearing on the effective use or operation of this product 3.2.10 sampling plan a plan according to which one or more samples are taken in order to obtain information and possibly to reac
22、h a decision prEN 4621:2008 5 3.2.11 limiting quality (LQ10) in a sampling plan, the quality limit which corresponds to a specified 10 % probability of acceptance NOTE 1 It is the limiting lot quality characteristic that the consumer is willing to accept with a low probability that a lot of this qua
23、lity would occur. NOTE 2 For the purposes of this Standard, the limiting quality quoted in Table 4 corresponds to a probability of acceptance of 10 %. 3.2.12 acceptance quality limit (AQL) a quality limit which in a sampling plan corresponds to a specified but relatively high probability of acceptan
24、ce It is the maximum per cent defective (or the maximum number of defects per hundred units) that, for purposes of sampling inspection can be considered satisfactory as a process average. 3.2.13 finished insert an insert ready for use, inclusive of any possible treatments and/or surface coatings, as
25、 specified in the definition document 3.2.14 definition document document specifying all the requirements for finished inserts 3.2.15 self-locking torque the torque to be applied to the associated bolt to maintain movement of rotation in relation to the part, the assembly being under no axial load a
26、nd the insert locking zone being completely engaged with the bolt (minimum protrusion of two pitches, including the end chamfer) 3.2.16 seating torque the tightening torque to be applied to the insert or bolt to introduce or to increase the axial load in the assembly 3.2.17 unseating torque the unti
27、ghtening torque to be applied to the insert or bolt to reduce or remove the axial load in the assembly 3.2.18 breakaway torque the torque required to start unscrewing the insert or the bolt from the associated part, with the insert locking device still fully engaged on the bolt, but after the axial
28、load in the assembly has been removed by unscrewing half a turn followed by a halt in rotational movement prEN 4621:20086 4 Quality assurance 4.1 Qualification EN 9133 Qualification inspections and tests (requirements, methods, numbers of inserts with self-broaching keys) are specified in Table 1. T
29、hey shall be carried out on: each type and diameter of inserts; 39 inserts selected from a single batch by simple random sampling. The test programme may possibly be reduced, or the qualification be granted without inspection or testing: Any such decision shall be based on the results obtained on si
30、milar types and diameters of inserts provided that the design and manufacturing conditions are identical. Table 2 indicates the allocation of insert samples for the inspections and tests. 4.2 Acceptance 4.2.1 Purpose The purpose of acceptance inspections and tests is to check, as simply as possible,
31、 by a method representative of actual use conditions, with the uncertainty inherent to statistical sampling, that the inserts constituting the batch satisfy the requirements of this standard. 4.2.2 Conditions Acceptance inspections and tests (requirements, methods, numbers of inserts) are specified
32、in Table 1. They shall be carried out on each batch inserts from the batch to be tested shall be selected by simple random sampling. Each insert may be submitted to several inspections or tests. If a more stringent inspection is deemed necessary, all or part of the qualification inspections and test
33、s may be performed during the acceptance inspections and tests. In this case, the number of inserts submitted to these inspections and tests is the same as that submitted for qualification inspection and tests. 4.2.3 Responsibility Acceptance inspections and tests shall be carried out by the manufac
34、turer, or under his responsibility. 4.2.4 Inspection and test report A test report showing actual numerical values shall be provided if specified in the purchase order. 5 Requirements See Table 1. prEN 4621:2008 7 Table 1 Technical requirements and test methods Clause Characteristic Requirement Insp
35、ection and test method Q/A aSample size Q 5.1 Material In accordance with the definition document Chemical analysis or certificate of conformity issued by the manufacturer of the semi-finished product A Q 39 5.2 Dimensions, tolerances and tolerances of form and position In accordance with the defini
36、tion document A “GO” inspection gauge is to be fitted on the insert keys. On completion of this inspection, the keys must neither be bent nor moved. Standard gauging See Annex E. A Tables 3 and 4 5.3 Manufacturing 5.3.1 Process Insert threads may be produced by machining or forming. Manufacturing me
37、thod shall be indicated on test report. The heat treatment medium or atmosphere shall not cause any surface contamination. Calibration of the heat treatment equipment shall be confirmed. Any scale which will not be removed by subsequent machining shall be removed by abrasive blasting with an appropr
38、iate equipment. Visual examination 5.3.2 Heat treatment The material shall be heat treated in accordance with the material specification defined in the definition document. Examination of the heat treatment specification 5.3.3 Q 39 Thread deformation (form out-of round) Threads in the locking zone m
39、ay be deformed in any manner provided that the insert meets the requirements of this standard. The finished inserts shall allow the “GO“ thread plug gauge to enter a minimum of three turns, when gauged from the installation side before engagement in the locking zone. Standard gauging A Tables 3 and
40、4 Q 3 5.3.4 Surface roughness In accordance with the definition document ISO 4288 A Tables 3 and 4 Q 36 A Tables 3 and 4 5.3.5 Surface coating In accordance with the definition document See applicable coating standard. A Table 6 continued prEN 4621:2008 8 Table 1 (continued) Clause Characteristic Re
41、quirement Inspection and test method Q/A aSample size 5.4 Mechanical properties Q 5 5.4.1 Installation requirement The screwing of insert shall be possible freely by hand. After testing, the inserts shall show no signs of: buckling and/or incomplete fitting of the keys; deformation of the internal t
42、hread of the insert caused by keys installation. Inserts shall be installed into test block (see Annex A, normative) in accordance with EN 4619. Use a tool specified in accordance with EN 4619. Visual examination at a suitable magnification of 10 to 20 The recorded hardness of the test blocks must b
43、e indicated in the test report A Table 5 5.4.1.1 into test block in aluminium See 5.4.1. See 5.4.1. Q 14 5.4.1.2 into test block in corrosion resisting steel See 5.4.1. See 5.4.1. Q 16 5.4.1.3 into test block in titanium alloy See 5.4.1. See 5.4.1. Q 6 5.4.2 Rotational resistance Q 5 5.4.2.1 into te
44、st block in aluminium alloy Inserts shall withstand the torque specified in Table B.1 without rotation. Inserts shall be installed in accordance with 5.4.1.1 The installed inserts shall be tested in a counter clockwise direction as shown in Annex B (normative). Q 5 5.4.2.2 into test block in corrosi
45、on resisting steel bSee 5.4.2.1. Inserts shall be installed into test block in corrosion resisting steel (see Annex A). Test method, see 5.4.2.1. continued prEN 4621:2008 9 Table 1 (continued) Clause Characteristic Requirement Inspection and test method Q/A aSample size Q 6 c5.4.3 Axial loadbInserts
46、 shall withstand axial strength corresponding to the strength class given in the definition document or in the material specification. Insert shall not axially move from the test block. Minimal length of external thread of the insert shall be fixed in the producer design. After testing inserts shall
47、 be free from: cracks; tearing or deformation of the internal thread of the insert preventing disassembly of the bolt. Permanent distortion or loss up to 40 % of the locking torque with regard with the breakaway torque recorded before axial load application is acceptable. Inserts shall be installed
48、in accordance with 5.4.1.1 and 5.4.1.2. The breakaway torque shall be recorded. The axial strength values specified in Annex C (normative) or in the definition document shall apply. 5.4.4 Reusability General: After testing, inserts shall not show any indications of distortion, galling or scratches o
49、f such a depth as to prevent reassembly of bolts freely, by hand, up to the self-locking zone. Bolt threads shall remain serviceable and permit assembly with a new insert freely, by hand, up to the self-locking zone. Test assembly see Annex D (normative) A new bolt shall be used for each complete 3, 5 and 25 cycles test. The pitch diameter of the bolts selected shall be in the lower 1/3 of tolerance specified in ISO 5855-1 and ISO 5855-2. During testing, the pitch diameter of the bolts may be checked and if fou
