1、AECMA PREN275q 87 LOL23LL_OOY113 O A. E .C. M .A. STAN DARD prEN2754 NORME A.E.C.M.A. Issue P 1 A.E.C.M.A. NORM February 1987 DIT PAR LASSOCIATION EUROPENNE DES CONSTRUCTEURS DE MATRIEL AROSPATIAL 88, boulevard Malesherbes, 75008 PARIS -TL. 45-63-82-85 Edition approved for publication 16 February 19
2、87 UDC : d 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 Key words : ENGLISH VERSION Aerospace series Nuts, anchor, self locking two lug, floating with counterbore Classification : I I O0 MPa/
3、235 OC Srie arospatiale Luft- und Raumfahrt Ecrous river freinage interne flottants, double patte Classification : 1 I O0 MPa/235 OC Gehuse-Annietmuttern, selbstsichernd, beweglich, beiderseitiger Flansch Klasse : 1 1 O0 MPa/235 OC avec chambrage mit zylindrischer Aussenkung This standard is initial
4、ly 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 countries, After examination and signatur
5、e 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. AECMA PREN2754 87 W JOL23LL OOOYLLY 2 W Issue P 1 prEN2754 Page 3 1 Scope This standard specifies the ch
6、aracteristics of two lug, counterbored, floating anchor nuts, with a self-locking feature achieved by forming the upper portion out-of-round, the dimensions of which are in conformity with IS0 3209. 2 Field of application These nuts are intended for use in aircraft assemblies, in which the fasteners
7、 are mainly subjected to shear loads. The counterbore of nuts with thread diameter equal to or greater than 4 mm is deep enough to accomodate a bolt shank in excess of assembly thickness, as well as the incomplete threads. a - The 3 mm diameter nut has no counterbore. They are intended to be used wi
8、th threaded parts of 1100 MPa 1) tensile strength classification. The cadmium plating restricts the application to temperatures not exceeding 235 OC, 3 References IS0 3209, IS0 585511, O IS0 585512, IS0 5858, IS0 8788, Aerospace - Metric fasteners - Nuts, anchor, self-locking, floating, two-lug, wit
9、h counterbore - Dimensions 2) Aerospace construction - MJ Threads - Part 1 : Basic profile Aerospace construction - MJ Threads - Part 2 : Dimensions for bolts and nuts Aerospace - Fasteners - Self locking nuts with maximum operating temperature less than or equal to 425 OC - Procure- ment specificat
10、ion 2) Aerospace - Fasteners - Tolerances of form and position for nuts 2) 1) This strength class applies at room temperatures. 2) In preparation O Previous page is blank Issue P 1 prEN2754 Page 4 ENZOOB, Aerospace series - Quality Assurance requirements for the manufacture and procurement of EN aer
11、ospace standard products EN2133, Cadmium plating of steels with maximum specified tensile strength equal or less than 1450 MPa, and copper and copper alloys - Aerospace series - EN2424, Identification marking of standard fasteners - Aerospace series EN2491, Aerospace series - Molybdenum disulphide s
12、olid film lubri- cants for application to removable fasteners in titanium, titanium alloy, corrosion resisting steel and cadmium plating steel 2) EN2542, EN2543, Aerospace series - Steel FE-PL43S Rm 1400 MPa - Bar and wire - De - 40 mm - Only for prevailig torque nuts 2) Aerospace series - Steel FE-
13、PL43S - 1250 Rm 1400 MPa - Sheets and strips - 0,3 - A - 2 mm - Only for prevailing torque nuts 2) 4 Required characteristics 4,l Configuration - Dimensions - Tolerances The configuration shall be in accordance with the figure ; the dimensions and tolerances shall conform to the values shown in the
14、figure and in table 1, before cadmium plating and MoS2 lubrication. 4.2 Surface roughness See figure. The values apply before cadmium plating and MoS2 lubrication. They donot apply to the thread, sheared-off edges and punched holes obtained by common manufacturing processes. 4.3 Materials Steel EN25
15、42 or EN2543. 4.4 Surface treatment Cadmium plating EN2133, 5 pm minimum on the threads and all areas which can be contacted by a 20 mm diameter ball. On all other areas, a continuous deposit shall be present, but no minimum value is Specified. Lubrication by Mos2 EN2491, mandatory on threads, optio
16、nal on other surfaces. 2) In preparation. AECIA PREN2754 87 1012311 OOOYlLb b . Issue P 1 prEN2754 Page 5 “V ( “U) Break sharp edges 0,l to 0,4 mm Section Y-Y * Floaf included Radius 5 L U C al 0 C m w u- O U AECMA PREN2754 87 W LO1Z3Ll O_O_OLlLI8 T W Number of EN Standard Issue P 1 prEN2754 Page 7
17、a - = hole code (see table 2) i 5 Designation Each nut shall only be designated as in the following example : Description Block NUT, ANCHOR Table 2 identity Block Plain rivet holes Dimpled rivet holes Note : If necessary the originator code 59005 may be introduced between the description block and the identity block. 6 Marking O Each nut shall be marked in any of the positions shown on the figure in accordance with EN2424, Style F. 7 Technical specification Conforming to IS0 5858 except for quality assurance requirements - See ENZOOO.
