1、1 AECMA PREN2648 87 e LOL234L00037BL 3 W - Edition approved for publication 16 February 1987 A.E.C. M.A. STAN DARD prEN2648 NORME A.E.C.M.A. Issue P 1 A.E.C.M.A. NORM February 1987 EDIT PAR LASSOCIATION EUROPENNE DES CONSTRUCTEURS DE MATRIEL AROSPATIAL 88, boulevard Malesherbes, 75008 PARIS -TL. 45-
2、63-82-85 Comments should be sent within six months C3 Chairman after the date of publication decision 88, Bd. Malesherbes A.E.C.M.A. Mr ARENA 75008 PARIS - FRANCE UDC : Key words : Srie arospatiale Rondelles, concaves ENGLISH VERSION Aerospace series Washers, concave Luft- und Raumfahrt Scheiben fr
3、Neigungsausgleich This standard is initially published on green paper for the needs of AECMA-Members (Association Europenne des Constructeurs de Matriel Arospatial). It has been technically approved by the experts of the concerned AECMA Commission following comment by the manufacturers of the Member
4、 countries. 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 published in its final version on yellow paper as an AECMA Standard. Nota - Extra copies can be supplied by B.N.A.E. - 8, rue Morea
5、u-Vauthier - 92100 BOULOGNE-BILLANCOURT I I Copyright Association Europeene des Constructeurs de Materiel Aerospatial Provided by IHS under license with AECMANot for ResaleNo reproduction or networking permitted without license from IHS-,-,-AECMA PREN2bQ8 87 1OL231L 0003782 5 BPI Issue P 1 prEN2648
6、Page 3 Previous page is blank 1 This standard specifies the characteristics of concave washers, for use in aerospace applications, normally in conjunction with EN2647. These two items, when used together, allow misalignment of the bearing surface with respect to the assembly axis of 6 maximum. Scope
7、 and field of application The cadmium plating restricts the application to temperatures not exceeding 235OC. 2 References EN2133, Cadmium plating of steels with maximum specified tensile strength equal to or less than 1450 MPa, and copper and copper alloys - Aerospace series EN2424, Identification m
8、arking of standard fasteners - Aerospace series EN2542, Aerospace series - Steel FE-PL43S - 1250 MPa Rm 1400 MEa - Bars De 5 40 mm - Only for prevailing torque nuts 1)- EN2647, Aerospace series - Nuts, hexagon, self-locking, ball seat - Classification 900 MPa/235 OC. 3 Required characteristics 3.1 C
9、onfiguration - Dimensions - Tolerances The configuration shall correspond with the figure ; the dimensions and tolerances shall conform to the values shown in the figure and in the table after cadmium plating. 3.2 Surface roughness See figure. The values apply prior to cadmium plating. They do not a
10、pply to the sheared edges ; the surface roughness will be as achieved by normal methods of manufacture. n 3 3 Materials Steel EN2542. 3.4 Surface treatment Cadmium plating, EN2133, 8 to 14 um. i) in preparation. Copyright Association Europeene des Constructeurs de Materiel Aerospatial Provided by IH
11、S under license with AECMANot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Issue P 1 prEN248 Page 4 - AECMA PRENZb4B 87 = 1012311 0003783 7 M Break all corners 0,1 to 0,4 rnrn. Marking to be applied on periphery. (see clause 5) Section X-X Figure - Configuration Tab
12、le - Dimensions and masses Dimensions in millimetres Size i) G L M R T Mass O O max . 050 10,3 7 290 8 835 098 06 O 13,O 892 295 9 9,2 194 080 17,O 11 395 12,5 13,25 333 1 O0 21 ,o 13,8 4 16 16,9 695 120 24,O 16,5 590 18 19,5 839 code +os2 +0,2 - +o, 1 +os5 - 3632 kg/1000 pieces 1) Size code aligns
13、with thread code of companion nut, Copyright Association Europeene des Constructeurs de Materiel Aerospatial Provided by IHS under license with AECMANot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Issue P 1 prEN2648 Page 5 4 Designation Each washer shall only be de
14、signated as in the following example : Description Block WASHER, CONCAVE Identity Block EN: _. Number of EN Standard 48-0f - 060 : Size code (see table) Note : If necessary the originator code S9005 may be introduced between the description block and the identity block. 5 Marking Each washer shall be marked in the position shown on the figure in accor- dance with EN2424, Style H. Copyright Association Europeene des Constructeurs de Materiel Aerospatial Provided by IHS under license with AECMANot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
