1、AECMA PREN*4249 96 m 3032333 0030546 832 m Nota - Extra copies can be supplied by B.N.A.E. - Technopolis 54 - 199, rue Jean-Jacques Rousseau - 921 38 ISSY-LES-MOULINEAUX CEDEX Comments should be sent within six months after the date of publication to C3 Chairman Edition approved for publication AECM
2、A STANDARD NORME AECMA AECMA NORM I prEN 4249 Edition P 1 May 1996 L PUBLISHED BY THE EUROPEAN ASSOCIATION OF AEROSPACE INDUSTRIES (AECMA) Gulledelle 94 - 8-1200 BRUXELLES - Tel. 132) 2 775 81 10 - Fax. (32) 2 775 81 11 ICs : 49.040.20 ENGLISH VERSION Aerospace series Nuts, anchor, self-locking, fix
3、ed, single lug, reduced series, with counterbore, in heat resisting steel, silver plated Classification : 1 1 O0 MPa (at ambient temperature) / 425 OC Srie arospatiale crous river, freinage interne, fixes, simple patte, srie rduite, avec chambrage, en acier rsistant chaud, argents Classification : 1
4、 100 MPa ( temprature ambiante) I425 OC Luft- und Raumfahrt Annietmuttern, selbstsichernd, einseitiger verkrzter Flansch, mit zylindrischer Aussenkung, aus hochwarmfestem Stahl, versilbert Klasse : 1 100 MPa (bei Raumtemperaturl / 425 OC This “Aerospace Series“ Prestandard has been drawn up under th
5、e 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 the Member countries. Subsequent to the publication o
6、f 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 Centre (NPS) and formal agreement of the Official Ser
7、vices of the Member countries it will be submitted as a draft European Standard to CEN (European Committee for Standardization) for formal vote. 1996-05-31 AECMA Gulledelle 94 B-1200 BRUXELLES Mr Arena I I I I aecrna 1996 Page 3 prEN 4249 : 1996 1 Scope This standard specifies the characteristics of
8、 self-locking, fixed, single lug anchor nuts, reduced series, with counterbore, in heat resisting steel, silver plated. Classification : 1 100 MPa 1) / 425 OC 2) 2 Normative references IS0 31 91 Aerospace - Self-locking, fixed, single-lug anchor nuts, reduced series, with counterbore, strength class
9、ification 1 1 O0 MPa and maximum operating temperature 235 OC IS0 5855-2 Aerospace - MJ threads - Part 2 : Limit dimensions for bolts and nuts IS0 5858 Aerospace - Self-locking nuts with maximum operating temperature less than or equal to 425 OC - Procurement specification IS0 8788 Aerospace - Faste
10、ners - Tolerances of form and position for nuts EN 2000 Aerospace series - Quality assurance - EN aerospace products - Approval of the quality system of manufacturers EN 2424 Aerospace series - Marking of aerospace products EN 2786 Aerospace series - Electrolytic silver plating of fasteners 3) EN 30
11、42 Aerospace series - Quality assurance - EN aerospace products - Qualification procedure TR 3791 Aerospace series - Materials for all metal self-locking nuts and thin wall inserts of temperature classes I425 OC 4) 1) Corresponds to the minimum tensile stress which the nut is able to withstand at am
12、bient temperature without breaking or cracking when tested with 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 condition
13、ed by the dimensions. 3) Published as AECMA Prestandard at the date of publication of this standard 4) Published as AECMA Technical Report at the date of publication of this standard _ AECMA PWEhl*4Z!it% efb = 1012311 0030549 543 Page 4 prEN 4249 : 1996 3 Required characteristics 3.1 See figure 1 an
14、d table 1. Dimensions and tolerances are : in conformity with IS0 3191, expressed in millimetres and apply after surface treatment. Details of form not stated are at the manufacturers option. The cap shall remain joined (type of attachment at the users discretion) to the nut at the maximum operating
15、 temperature. See test conditions in IS0 5858. Configuration - Dimensions - Masses 3.2 Tolerances of form and position IS0 8788 3.3 Materials TR 3791 3.4 Surface treatment EN 2786, thickness : - on external surfaces : 5 pm to 15 pm ; - on pitch diameter : 5 pm min. for nuts MJ6. Nuts MJ5 and smaller
16、 shall show complete coverage over complete profile. AECMA PREN*424 b 1012311 0010550 2b3 Remove sharp edges 0,l to 0,4 Radius= K/2 - Page 5 prEN 4249 : 1996 I Y-Y - Form out-of-round in this area to achieve the self-locking torque requirement 2). Configuration with cap P- I) These values in microme
17、tres 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) Tooling marks are permitted in this area. Figure 1 Diameter1 Thread 1 C 1 D 1 E max. max. code 1 MJ4x0,7-4H6H 1 11,:
18、1 MJ50,8-4H6H 0.4 7,4 MJ6xl-4H5H Table 1 1 ) In accordance with IS0 5855-2. In self-locking zone the tolerances apply before forming out-of-round. 2) Measured at sharp corners (chamfered) or points of tangency iradiused) 3) Measured at the rivet hole location 4) Maximum protrusion of the bolt 5) App
19、roximate values (kg/l O00 pieces), given for information puposes only. They apply to anchor nuts without cap. AECMA PREN*424 b = 1012311 0010551 1TT Description block Page 6 prEN 4249 : 1996 Identity block 4 Designation EXAMPLE : NOTE : If necessary, the code 19005 shall be placed between the cscription block and the identity block. Table 2 without with 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.
