1、ASD-STAN STANDARD NORME ASD-STAN ASD-STAN NORM prEN 2943 Edition P 2 October 2014 PUBLISHED BY THE AEROSPACE AND DEFENCE INDUSTRIES ASSOCIATION OF EUROPE - STANDARDIZATION Rue Montoyer 10 - 1000 Brussels - Tel. 32 2 775 8126 - Fax. 32 2 775 8131 - www.asd-stan.org ICS: 49.030.10 Supersedes issue P 1
2、 of October 1990 and will supersede EN 2943:1998 Descriptors: ENGLISH VERSION Aerospace series Inserts, screw thread, helical coil, self-locking Technical specification Srie arospatiale Filets rapports freinage interne Spcification technique Luft- und Raumfahrt Draht-Gewindeeinstze, selbstsichernd T
3、echnische Lieferbedingung 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 has been technically approved by t
4、he 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 standard. After examination and r
5、eview 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 the EN at national level by giv
6、ing the EN the status of a national standard and by withdrawing any national standards conflicting with the EN. Edition approved for publication 1st October 2014 Comments should be sent within six months after the date of publication to ASD-STAN Mechanical Domain Copyright 2014 by ASD-STAN prEN 2943
7、:2014 (E) 2 Contents Page Foreword 2 1 Scope 3 2 Normative references 3 3 Terms and definitions . 4 4 Quality assurance 6 5 Requirements . 7 Annex A (normative) Definition of maximum and minimum mandrels for the permanent set test 14 Annex B (normative) Assembly for reusability tests . 16 Annex C (n
8、ormative) Definition of test bolt for reusability tests 17 Annex D (normative) Definition of spacer for reusability tests 18 Annex E (informative) Standard evolution form . 19 Foreword This standard was reviewed by the Domain Technical Coordinator of ASD-STANs Mechanical Domain. After inquiries and
9、votes carried out in accordance with the rules of ASD-STAN defined in ASD-STANs General Process Manual, this standard has received approval for Publication. prEN 2943:2014 (E) 3 1 Scope This standard specifies the characteristics, qualification and acceptance requirements for self-locking helical co
10、il screw thread inserts in NI-PH2801 or FE-PA3004, with or without surface coating. It is applicable whenever referenced. 2 Normative references The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references,
11、only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. EN 2398, Aerospace series Heat resisting steel FE-PA2601 (X6NiCrTiMoV26-15) Rm 900 MPa Bars for machined bolts D 25 mm EN 2945, Aerospace series Inserts, screw th
12、read, helical coil, self-locking Assembly procedure EN 3044, Aerospace series Installation holes for inserts, screw thread, helical coil, self-locking Design standard EN 3219, Aerospace series Heat resisting nickel base alloy (NI-P100HT) Cold worked and softened Bar and wire for continuous forging o
13、r extrusion for fasteners 3 D 30 mm 1) EN 9133, Aerospace series Quality management systems Qualification procedure for aerospace standard parts EN ISO 4288, Geometrical Product Specifications (GPS) Surface texture: Profile method Rules and procedures for the assessment of surface texture (ISO 4288:
14、1996/Cor 1:1998) ISO 2859-1:1989, Sampling procedures for inspection by attributes Part 1: Sampling plans indexed by acceptable quality level (AQL) for lot-by-lot inspection ISO 3353 (all parts), Aerospace Lead and runout threads ISO 3534-2:2006, Statistics Vocabulary and symbols Part 2: Applied sta
15、tistics ISO 3951 (all parts), Sampling procedures for inspection by variables ISO 5855-2, Aerospace MJ threads Part 2: Limit dimensions for bolts and nuts ISO 9000:2005, Quality management systems Fundamentals and vocabulary 1) Published as ASD-STAN Prestandard at the date of publication of this sta
16、ndard. http:/www.asd-stan.org/ prEN 2943:2014 (E) 4 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 batch quantity of finished thread inserts, of the same type and same diameter, produced from a material obtained from the same melt, manufactu
17、red in the course of the same production cycle, following the same manufacturing route and having undergone all the relevant heat treatments and surface treatments 3.2 surface discontinuities 3.2.1 crack rupture in the material which may extend in any direction and which may be intercrystalline or t
18、ranscrystalline 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 compressing them into the surface 3.2.4 inclusions non-metallic particles originating from the material manufacturing process NOTE 1 to entry: These partic
19、les may be isolated or arranged in strings. 3.3 test temperature ambient temperature, unless otherwise specified 3.4 simple random sampling sampling where a sample of n sampling units is taken from a population in such a way that all the possible combinations of n sampling units have the same probab
20、ility of being taken NOTE 1 to entry: In bulk sampling, if the sampling unit is an increment, the positioning, delimitation and extraction of increments is such that all sampling units have an equal probability of being selected. SOURCE: ISO 3534-2:2006, 1.3.4; modified: without references to the so
21、urce document 3.5 defect non-fulfilment of a requirement related to an intended or specified use NOTE 1 to entry: The distinction between the concepts defect and nonconformity is important as it has legal connotations, particularly those associated with product liability issues. Consequently, the te
22、rm “defect” should be used with extreme caution. NOTE 2 to entry: The intended use by the customer can be affected by the nature of the information, such as operating or maintenance instructions, provided by the customer. SOURCE: ISO 9000:2005, 3.6.3 prEN 2943:2014 (E) 5 3.6 sampling plan bulk mater
23、ial specification of the type of sampling to be used combined with the operational specification of the entities or increments to be taken, the samples to be constituted and the measurements/tests to be made NOTE 1 to entry: The plan may specify, for example, that the sampling is systematic and in t
24、wo stages. In combination with the specification of the type of sampling, the plan, in this example, also may specify the number of increments to be taken from a lot, the number of composite samples (or gross samples) per lot, the number of test samples per composite sample, and the number of measur
25、ements/tests per test sample. SOURCE: ISO 3534-2:2006, 5.4.3; modified: without references to the source document 3.7 limiting quality in a sampling plan, the quality level which corresponds to the specified 10 % probability of acceptance 3.8 Acceptable Quality Level AQL acceptance sampling worst to
26、lerable quality level NOTE 1 to entry: This concept only applies when an acceptance sampling scheme with rules for switching and for discontinuation, such as ISO 2859-1 and ISO 3951, is used. NOTE 2 to entry: Although individual lots with quality as bad as the acceptance quality limit can be accepte
27、d with fairly high probability, the designation of an acceptance quality limit does not suggest that this is a desirable quality level. NOTE 3 to entry: Acceptance sampling schemes found in standards such as ISO 2859-1 with their rules for switching and for discontinuation of sampling inspection are
28、 designed to encourage suppliers to have process averages consistently better than the acceptance quality limit. If suppliers fail to do so, there is a high probability of being switched from normal inspection to tightened inspection where lot acceptance becomes more difficult. Once on tightened ins
29、pection, unless action is taken to improve the process, it is very likely that the rule requiring discontinuation of sampling inspection pending such improvement will be invoked. NOTE 4 to entry: The use of the abbreviation AQL to mean “acceptable quality level” is no longer recommended. SOURCE: ISO
30、 3534-2:2006, 4.6.15; modified: without references to the source document 3.9 finished thread insert a thread insert ready for use, inclusive of any possible treatments and/or surface coatings, as specified in the product standards or definition document 3.10 definition document document specifying
31、all the requirements for finished thread inserts 3.11 self-locking torque The torque to be applied to the associated bolt to maintain its movement of rotation in relation to the thread insert assembly which is under no axial load and the thread insert locking zone being completely engaged with the b
32、olt (minimum protrusion of two pitches, including the end chamfer) 3.12 seating torque the tightening torque to be applied to the thread insert and bolt assembly to introduce or to increase the axial load in the assembly prEN 2943:2014 (E) 6 3.13 unseating torque the untightening torque to be applie
33、d to the thread insert and bolt assembly to reduce or remove the axial load in the assembly 3.14 breakaway torque the torque required to start unscrewing the associated bolt with respect to the installed thread insert, with the insert locking zone still fully engaged on the bolt, but after the axial
34、 load in the assembly has been removed by unscrewing half a turn followed by a halt in rotational movement 4 Quality assurance 4.1 Qualification See EN 9133. Qualification inspections and tests (requirements, methods, numbers of thread inserts) are specified in Table 1. They shall be carried out on:
35、 each type and diameter of thread insert; 26 thread 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 similar types and
36、 diameters of thread inserts provided that the design and manufacturing conditions are identical. Table 2 indicates the allocation of thread insert specimens 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
37、, by a method representative of actual use conditions, with the uncertainty inherent to statistical sampling, that the thread inserts constituting the batch satisfy the requirements of this standard. 4.2.2 Conditions Acceptance inspections and tests (requirements, methods, numbers of thread inserts)
38、 are specified in Table 1. They shall be carried out on each batch. Thread inserts from the batch to be tested shall be selected by simple random sampling. Each thread insert may be submitted to several inspections or tests. If a more stringent inspection is deemed necessary, all or part of the qual
39、ification inspections and tests may be performed during the acceptance inspection and testing. In this case, the number of thread 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 tes
40、ts shall be carried out by the manufacturer, or under his responsibility. prEN 2943:2014 (E) 7 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. Table 1 Technical requirements and test meth
41、ods (1 of 4) Clause Characteristic Requirement Inspection and test method Q/A a Sample size 5.1 Material In accordance with the product standard or definition document Chemical analysis or certificate of compliance issued by the manufacturer of the semi-finished product Q A 5.2 Dimensions, tolerance
42、s and tolerances of form and position In accordance with the product standard or definition document Standard gauging Q 26 A Table 3 5.2.1 Thread In accordance with the product standard or definition document Standard gauging According to Table 4 The gauging has to be done from the opposite site of
43、the tang. The minimum requested number of coils above locking coil is 1.75. If specified part does not provide the minimum, test parts has to be produced and gauged. Q 5 A Table 3 5.3 Manufacturing 5.3.1 Surface roughness In accordance with the product standard or definition document EN ISO 4288 Vis
44、ual examination Q 3 A Table 3 5.3.2 Surface coating In accordance with the product standard or definition document See applicable coating standard. Q 23 A Table 3 5.4 Mechanical properties Thread inserts shall be assembled into test equipment according to EN 2945 (see Table 4). prEN 2943:2014 (E) 8
45、Table 1 Technical requirements and test methods (2 of 4) Clause Characteristic Requirement Inspection and test method Q/A a Sample size 5.4.1 Permanent set test (ambient temperature) Measured torques of the thread Inserts shall not exceed the maximum self-locking torque nor shall be less than the mi
46、nimum breakaway torque, see Table 5. When screwing and unscrewing the maximum and minimum mandrels, the rotation of the thread insert in its location shall not exceed 90. Lubricate the maximum Mandrel using clean engine oil. Fit the maximum mandrel in the thread insert, until it protrudes at least t
47、wo pitches beyond the locking zone of the thread insert, measuring the self-locking torque on screwing. Unscrew, removing the maximum mandrel completely from the thread insert. Carry out the same chronological sequence of operations using the minimum mandrel, measuring the breakaway torque. Check th
48、at the mandrel dimensions are within the limits given in annex A and that their threads have not been damaged. The rotation of the mandrels shall be sufficiently slow so that the temperature of the thread insert does not exceed 45 C during operations. Q 3 5.4.2 Reusability test When screwing and uns
49、crewing the bolt, the rotation of the thread insert in its location shall not exceed 90. Test equipment, see Table 4. Assembly, see Annex B. The self-locking torques shall be recorded for each cycle. prEN 2943:2014 (E) 9 Table 1 Technical requirements and test methods (3 of 4) Clause Characteristic Requirement Inspection and test method Q/A a Sample size 5.4.2.1 Self-locking torque at ambient temperature (15 cycles)
