1、- - _ STD-AECMA PREN 2881-ENGL 1778 E LO12311 0034823 b47 AECMA STANDARD prEN 2881 NORME AECMA Edition P 1 AECMA NORM June 1998 Edition approved for publication I 998-06-30 PUBLISHED BY THE EUROPEAN ASSOCIATION OF AEROSPACE INDUSTRIES (AECMA) Guliedeiie 94 - 8-1200 BRUXELLES - Tel. (+32) 2 775 81 10
2、 - Fax. (+32) 2 775 81 11 Comments should be sent within six months C3 Chairman after the date of publication to Guliedeiie 94 AECMA Mr Arena B-1200 BRUXELLES ICs: 49.030.30 I ENGLISH VERSION Aerospace series Nuts, anchor, self-locking, fuel resistant, sealing, floating, two lug, with counterbore, i
3、n corrosion resisting steel, passivated, Mos2 lubricated Classification: 900 MPa (at ambient temperature) / 120 OC Srie arospatiale crous river, freinage interne, tanches au carburant, flottants, double patte, avec chambrage, en acier rsistant la corrosion, passivs, lubrifis Mos2 Classification : 90
4、0 MPa temprature ambiante) / 120 OC Luft- und Raumfahrt Annietmuttern, selbstsichernd, druckdicht, kraftstoffbestnding, beweglich, beiderseitiger Flansch, mit zylindrischer Aussenkung, aus korrosionsbestndigem Stahl, passiviert, MoS2-geschmiert Klasse: 900 MPa (bei Raumtemperatur) / 120 OC This “Aer
5、ospace Series Prestandard has been drawn up under the responsibility of AECMA (The European Association of Aerospace Industries). It is published on green paper for the needs of AECMA-Members. It has been technically approved by the experts of the concerned Technical Committee following comment by t
6、he Member countries. 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 signature of the AECMA Standard Checking C
7、entre INPSI and formal agreement of the Official Services of the Member countries it will be submitted as a draft European Standard to CEN (European Committee for Standardization) for formal vote. Page 3 prEN 2881 : 1998 I Scope This standard specifies the characteristics of self-locking, fuel resis
8、tant, sealing, floating, two lug anchor nuts, with counterbore, in corrosion resisting steel, passivated, Mos2 lubricated. Classification: 900 MPa 1) / 120 OC 2) 2 Normative references IS0 5855-2 IS0 5858 IS0 8788 IS0 8940 EN 2000 EN 2424 EN 2491 EN 2516 EN 3042 MIL-R-6855 E TR 3791 Aerospace - MJ t
9、hreads - Part 2: Limit dimensions for bolts and nuts Aerospace - Self-locking nuts with maximum operating temperature less than or equal to 425 OC - Procurement specification Aerospace - Fasteners - Tolerances of form and position for nuts Aerospace - Nuts, anchor, self-locking, sealing, floating, t
10、wo lug, with counterbore, classifications 900 MPa / 120 OC, 900 MPa / 175 OC and 900 MPa / 235 OC - Dimensions Aerospace series - Quality assurance - EN aerospace products - Approval of the quality systems of manufacturers Aerospace series - Marking of aerospace products Aerospace series - Molybdenu
11、m disulphide dry lubricants - Coating methods Aerospace series - Passivation of corrosion resistant steels and decontamination of nickel base alloys Aerospace series - Quality assurance - EN aerospace products - Qualification procedure Rubber, Synthetic, Sheets, Strips, Molded or Extruded Shapes, Ge
12、neral Specification For 3) Aerospace series - Materials for self-locking nuts, threaded inserts and screw thread inserts of temperature classes I425 OC 4) 1) Corresponds to the minimum tensile stress which the nut is able to withstand at ambient temperature without breaking or cracking when tested w
13、ith 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 temperature is conditioned by the seal material. 3) Published by: Department of Defe
14、nse (DoD), the Pentagon, Washington, D.C. 20301, USA 4) Published as AECMA Technical Report at the date of publication of this standard 3 Required characteristics 3.1 See figure 1 and table 1. Configuration - Dimensions - Masses Dimensions and tolerances are: in conformity with IS0 8940, expressed i
15、n millimetres and apply after surface treatment but before Mos2 lubrication. Details of form not stated are at the manufacturers option. 3.2 Tolerances of form and prosition ISO a788 3.3 Materials Cage, seal retainer and nut element: TR 3791 Sealing ring: rubber, fuel resistant per MIL-R-6855, class
16、 1, grade 60 or equivalent 3.4 Surface treatments Cage and seal retainer: EN 2516 Nut element: EN 2491, thickness not specified, mandatory on threads, optional on other surfaces STD-AECMA PREN 2882-ENGL 1778 M LOL23LL UUL482b 35b M Page 5 prEN 2881: 1998 Diameter Thread 1) EFGHJKLMQ code min. min. m
17、ax. max. max. 050 MJ50,8-4H6H 9,5 19 6 3,4 16,2 14,4 24,6 060 MJ6xl-4H5H 11 22 7 19,2 17 29 080 MJ8xl-4H5H 13 26 9 20,3 19,4 32,5 4,l Remove sharp edges 0,l to 0,4. max. max. 7,9 12,5 9,5 16 11,3 18,5 Y-Y W 2) I Form out-of-round in this area to achieve the S + 0,2 O 2,5 3 I L Choice of flange at i
18、manufacturers discretion W Mass21 max. 14,4 4,3 17,4 7 18,5 10 1 2,8max. IJ 4 1) These values in micrometres apply before surface treatment. They do not apply to threads, punched holes or sheared edges the surface texture of which will be as achieved by usual manufacturing methods. 2) Maximum bolt t
19、hread intrusion 3) Minimum radial float of nut element: 0,5 4) Lug thickness at the rivet location Figure 1 Table 1 I 1 ) In accordance with IS0 5855-2. In the self-locking zone the tolerances apply before forming out-of-round. 2) Approximate values (kgll O00 pieces), given for information purposes
20、only STD-AECMA PREN 2881-ENGL 1778 101231L 0014827 272 Page 6 prEN 2881: 1998 4 Designation EXAMPLE: Description block Identity block Number of this standard Diameter code (see table 1) NOTE: If necessary, the code 19005 shall be placed between the description block and the identity block. 5 Marking EN 2424, style N. See figure 1. 6 Technical specification IS0 5858, except for: - Approval of manufacturers: see EN 2000; - Qualification of products: see EN 3042.
