1、A. E. C. M .AI STAN DAR D NORME A. E.C. M .A. A.E.C.M.A. NORM Edition approved for publication 20th January 1989 prEN 2856 Issue P 1 January 1989 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
2、EDITE PAR LASSOCIATION EUROPENNE DES CONSTRUCTEURS DE MATERIEL AROSPATIAL 88, boulevard Malesherbes, 75008 PARIS - TEL. 45-63-82-85 UDC : Key words : ENGLISH VERSION Aerospace series Nuts, anchor, self-locking, fixed, closed corner, reduced series, with counterbore Classification : I I O0 MPa/235 OC
3、 Srie arospatiale crous river freinage interne, fixes, angle ferm, srie rduite, avec chambrage Classification : 1100 MPa/235 OC Luft- und Raumfahrt Annietmuttern, selbstsichernd, einseitiger verkrzter Eck-Flansch mit zylindrischer Aussenkung Klasse : 1100 MPa/235 OC This Aerospace Series pre-standar
4、d has been drawn up under the responsibility of AECMA (Association Europenne des Constructeurs de Matriel Arospatial). It is published on green paper for the needs of AECMA-Members. It has been technically approved by the experts of the concerned AECMA Commission following comment by the Member coun
5、tries. Subsequent to the publication of this pre-standard, 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) a
6、nd formal agreement of the Official Services of the Member countries it will be submitted as a draft European Standard to CEN (European Committee fur Standardization) for final vote. AECMA PREN2856 89 1iOL23Ll 000283 3 . prEN 2856 Page 3 Issue P 1 1 Scope This standard specifies requirements for clo
7、sed corner, counterbored, fixed, reduced series anchor nuts, with a self-locking feature achieved by forming the upper portion out-of-round. 2 Field of application These nuts are intended for use in aircraft assemblies, in which the fasteners are mainly subjected to shear loads. The counterbore is d
8、eep etiugh to accommodate a bolt shank in excess of assembly thickness, as well as the incomplete threads. They are intended to be used with threaded parts of 1100 NPa 1) tensile strength classification, The cadmium plating restricts the application to temperature not exceeding 235 “C. 3 References
9、IS0 3222, Aerospace - Self-locking, fixed, closed-corner anchor nuts, reduced series, with counterbore - Classifications 1100 MPa/235 OC, 1100 MPa/ 315 “C and 1100 MPa/425 “C - Dimensions 2) IS0 5855/2, Aerospace construction - MJ Threads - Part 2 : Dimensions for bolts and nuts IS0 5858, IS0 8788,
10、EN 2000, EN 2133, EN 2424, EN 2491, EN 2542, EN 2543, Aerospace - Fasteners - SeIf-locking nuts with maximum operating temperature less than or equal to 425 C - Procurement specifica- tion 2) Aerospace - Fasteners - Tolerances of form and position for nuts Aerospace series - Quality assurance requir
11、ements for the manufac- ture and procurement of EN aerospace standard products 4) Cadmium plating of steel with maximum specified tensile strength equal to or less than 1450 ma, and copper and copper alloys - Aerospace series 4) Identification marking of standard fasteners - Aerospace series 4) Aero
12、space series - Application of molybdenum disulphide dry filn lubricants to removable fasteners in titanium, titanium alloy, corrosion resisting steels and cadmium plated steels Aerospace series - Steel FE-PL43S - 1250 strip 0,3 5 a L 2 mm - Only Previous page is blank 1) This strength class applies
13、at room 2) In preparation. 3) Published as AECMA pre-standard. 4) Published as AECMA standard. -PL43S - 1250 for prevailing temperature. Rm 1400 MPa - torsue nuts 3) Sheet atid AECNA PREN2856 87 LOLZ3LL 0004284 5 prEN 2856 Page 4 Issue P 1 4 Required characteristics 4.1 Configuration - Dimensions -
14、Tolerances The configuration shall be in accordance with the figure ; the dimensions and tolerances shall conform to the values shown in the figure and in the table, after cadmium plating but before MOS The dimensions are in conformity with IS0 3222 and the geometrical tolerances with IS0 8788. lubr
15、ication. 2 UStails of form not defined are at the option of the manufacturer. 4.2. Surface roughness See figure. Values apply prior to cadmium plating and lubrication. They do not apply to the thread, sheared edges and punched edges ; the surface roughness will be as achieved by normal methods of ma
16、nufacture. 4.3 Materials Steel. EN 2542 or EN 2543. 4.4 Surface treatement Cadmium plating EN 2133, 5pm 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 M
17、OS EN 2491, mandatory on threads, optional on other surfaces. 2 prEN 2856 Page 5 Issue P 1 Ramwd etwp bdBBI va1 to u.4 Fo wt-of-round in this srea to schiee b &-locking requirement (toding marks pernYs6Md in these areas Thread 1) Code I Designation 1: I MJ 4 x 0:7 - 4H6H MJ 5 x 0,8 - 4H6H 060 IMJ 6
18、x 1 - 4H5H Figure - Configuration Table - Dimensions and mass Dimensions in millimetres 1) In conformity with IS0 5855 part 2. In the self-locking zone, the tolerances apply before deformation, 2) Is to sharp corners (chamfered) or point of tangency (radiused). 3) Is applicable at the rivet hole loc
19、ation. prEN 2856 Page 6 Issue P 1 5 Designation Each nut shall only be de i Description block NUT, AKCHOR - iiated as in the following example Identity block Number of EN standard 060 = Thread code (see table) Note . If necessary the originator code 19605 may be introduced between the description block and the identity block 6 Karking Each nut shall be markeci in any of the positions shown on the figure in accordance with EM 2424, sty16 h. 7 Technical specification IS0 5858 plus EN 2000 for those aspects not covered by this IS0 standard.
