1、AECMA STANDARD NORME AECMA AECMA NORM Edition approved for publication Comments should be sent within six months after the date of oublication to prEN 2878 Edition P 1 June 1998 C3 Chairman PUBLISHED BY THE EUROPEAN ASSOCIATION OF AEROSPACE INDUSTRIES (AECMA) Gulledelle 94 - 8-1200 BRUXELLES - Tel.
2、(+32) 2 775 81 1 O - Fax. (32) 2 775 81 11 ICs: 49.030.30 Descriptors: ENGLISH VERSION Aerospace series Nuts, anchor, self-locking, air resistant, sealing, floating, two lug, with counterbore, in alloy steel, cadmium plated, Mos2 lubricated Classification: 900 MPa (at ambient temperature) / 235 OC S
3、rie arospatiale crous river, freinage interne, tanches lair, flottants, double patte, avec chambrage, en acier alli, cadmis, lubrifis Mos2 Classification : 900 MPa ( temprature ambiante) I235 OC Luft- und Raumfahrt Annietmuttern, selbstsichernd, druckdicht, luftbestnding, beweglich, beiderseitiger F
4、lansch, mit zylindrischer Aussenkung, aus legiertem Stahl, verkadmet, MoSz-geschmiert Klasse: 900 MPa (bei Raumtemperatur) / 235 OC This “Aerospace Series“ Prestandard has been drawn up under the responsibility of AECMA (The European Association of Aerospace Industries). It is published on green pap
5、er for the needs of AECMA-Members. It has been technically approved by the experts of the concerned Technical Committee following comment by the Member countries. Subsequent to the publication of this Prestandard, the technical content shall not be changed to an extent that interchangeability is aff
6、ected, physically or functionally, without re-identification of the standard. After examination and signature of the AECMA Standard Checking Centre (NPS) and formal agreement of the Official Services of the Member countries it will be submitted as a draft European Standard to CEN (European Committee
7、 for Standardization) for formal vote. 1998-06-30 AECMA Guiledelie 94 I E-1 200 BRUXELLES I Mr Arena 1 Scope Page 3 prEN 2878: 1998 This standard specifies the characteristics of self-locking, air resistant, sealing, floating, two lug anchor nuts, with counterbore, in alloy steel, cadmium plated, Mo
8、s2 lubricated. Classification: 900 MPa 1) / 235 OC 2) 2 Normative references IS0 5855-2 IS0 5858 Aerospace - MJ threads - Part 2: Limit dimensions for bolts and nuts Aerospace - Self-locking nuts with maximum operating temperature le equal to 425 OC - Procurement specification Aerospace - Fasteners
9、- Tolerances of form and position for nuts IS0 8788 s than or IS0 8940 EN 2000 EN 2133 EN 2424 EN 2491 EN 3042 AMS 3304G TR 3791 Aerospace - Nuts, anchor, self-locking, sealing, floating, two lug, with counterbore, classifications 900 MPa / 120 OC, 900 MPa / 175 OC and 900 MPa / 235 OC - Dimensions
10、Aerospace series - Quality assurance - EN aerospace products - Approval of the quality systems of manufacturers Aerospace series - Cadmium plating of steels, with maximum specified tensile strength equal to or less than 1 450 MPa, copper, copper alloys and nickel alloys 3) Aerospace series - Marking
11、 of aerospace products Aerospace series - Molybdenum disulphide dry lubricants - Coating methods Aerospace series - Quality assurance - EN aerospace products - Qualification procedure Silicone Rubber General Purpose 70 Durometer 4) Aerospace series - Materials for self-locking nuts, threaded inserts
12、 and screw thread inserts of temperature classes 5 425 OC 5) 1) Corresponds to the minimum tensile stress which the nut is able to withstand at ambient temperature without breaking or cracking when tested with a bolt of a higher strength class. 2) Maximum temperature that the nut is able to withstan
13、d, without permanent alteration to its original characteristics, after ambient temperature has been restored. The maximum temperature is conditioned by the cadmium plating. 3) Published as AECMA Standard at the date of publication of this standard 4) Published by: Society of Automotive Engineers, In
14、c. (SAE), 400 Commonwealth Drive, Warendale, 5) Published as AECMA Technical Report at the date of publication of this standard P.A. 15096-0001, USA Previous page is blank LOL23LL OOLqB40 72b Page 4 prEN 2878: 1998 3 Required characteristics 3.1 See figure 1 and table 1. Dimensions and tolerances ar
15、e: in conformity with IS0 8940, expressed in millimetres and apply after cadmium plating but before Mos2 lubrication. Configuration - Dimensions - Masses Details of form not stated are at the manufacturers option. 3.2 IS0 8788 Tolerances of form and prosition 3.3 Materials Cage, seal retainer and nu
16、t element: TR 3791 Sealing ring: rubber, air resistant per AMS 3304 or equivalent 3.4 Surface treatments Cage and seal retainer: EN 2133, 5 pm min. on all surfaces which can be contacted by a 20 mm diameter ball. On all other surfaces, a continuous deposit shall be present. Nut element: - EN 2133, 5
17、 pm min. on all surfaces which can be contacted by a 20 mm diameter ball. On all other surfaces, a continuous deposit shall be present; - EN 2491 , thickness not specified, mandatory on threads, optional on other surfaces. Remove sharp edges 0,l to 0,4. Diameter Thread 1) code 050 MJ50,8-4H6H 060 MJ
18、6x1-4H5H 080 MJ8x1-4H5H Y-Y E F G H J K L M Q S W Mass21 min. min. max. max. max. max. max. O max. + 0,2 9,5 19 6 3,4 16,2 14,4 24,6 7,9 12,5 14,4 4,3 2,s 11 22 7 19,2 17 29 9,5 16 17,4 7 13 26 9 20,3 19,4 32,5 11,3 18,5 3 18,5 10 4,1 Choice of flange at manufacturers discretion 2 holes S Page 5 prE
19、N 2878: 1998 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 thread intrusion 3) Minimum radial float of nut element: 0,5 4) Lu
20、g thickness at the rivet location Figure 1 Table 1 Page 6 prEN 2878: 1998 4 Designation EXAMPLE: Description block Identity block NUT ENy78-060 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.
