1、FED. SUP CLASS 5310 1. THE APPLICATION OF PRELOAD LOCKING “.ITS IN DESIGN AND CONSTRUCTION SRALL BE IN ACCORDANCE WITH THE FOLLOWING REQUIREMENTS; .1.1 PRELOAD LOCKING V“s MAY BE USED IN THE FOLLOWING APPLICATIONS: 1.1.1 WITH BOLTS, SCREWS, STUDS OR OTHER EXTERNALLY THREADED PARTS THAT HAVE ROCKWELL
2、 “C HARDNESS EQUAL TO THE NUT HARDNESS OR WITHIN THE HEAT TREAT RANGE IN TABLE I. TABLE I. HARDNESS AND HEAT TREAT RANGES I MATING BOLT, SCREW, STUDS OR I (HEAT TREAT RANGE) PRELOADING NUT (ROCKWELL .C“ HARDNESS) OTHER EXTERNALLY THREADED PART I - C32 - C36 C32 - Ci9 (150 KSI TO 180 KSI) C36 - C40 C
3、34 - C43 (160 KSI TO 200 KSI) C40 - C44 C39 - C49 (180 KSI TO 240 KSI) 1.1.2 ALLJOINTS IN CONTROL SYSTEMS AT SINGLE ATTACHMENTS OR WHERE LOSS OF BOLT WOULD AFFECT SAFETY OF FLIGHT WHEN THREADED PARTS ARE HELD BY A POSITIVE LOCKING DEVICE THAT REQUIRES SHEARING OR RUPTURE OF MATERIALS BEFORE TORSIONA
4、L LOADS WOULD RELIEVE INITIAL STRESS. 1.1.3 ON ANY EXTERNALLY THREADED PART THAT SERVES AS AN AXIS OF ROTATION FOR ANOTHER PART WHEN . THREADED PART TO RELIEVE INITIAL STRESS, AND THE THREADED PARTS HAVE IMPEDANCE TYPE THERE ARE NO TORSIONAL LOADS WHICH CAN BE APPLIED TO EITHER AN EXTERNALLY OR INTE
5、RNALLY LOCKING ELEMENTS IN ACCORDANCE WITH MIL-F-18240, MIL-F-8961 OR MIL-N-25027. 1.1.4 IN AIRPRAHES, AIRFRAMES MECHANICAL AND FLUID SUBSYWWS RND AIRBORNE SPECIAL MISSION SYSTEMS, IF USED IN COMBINATION WITH AN APPROVED IHPDANCETYPE SELF-LOCKING SCREW THREAD ELEMENT, AS IDENTIFIED BY MIL-F-18240, M
6、IL-F-8961, AND MIL-N-25027: OR WITH AN APPROVED POSITIVE LOCKING DEVICE SUCH Ac COTTER PIN OR LOCKWIRE WHERE A SINGLE DISCONNECT, MISSING, FAILURE, OR LOSS OF THE THREADED PART, DURING ANY OPERATING CONDITION, COULD CAUSE ONE OR MORE OF THE FOLLOWING SITUATIONS. A. LOSS OF AIRCRAFT B. PRECLUDE CONTI
7、NUED FLIGHT AND LANDING WITHIN THE DESIGN LIMITATIONS OF THE AIRCRAFT, USING NORHAL PILOT SKILL AND STRENGTH. C. SIGNIFICANT INJURY TO OCCUPANTS OF THE AIRCRAFT OR GROUND PERSONNEL. D. RENDER A MAJOR SUBSYSTEM OR SPECIAL MISSION SYSTEM INOPERATIVE, OR CAUSE ITS DESTRUCTION. E. CAUSE THE UNINTENTIONA
8、L RELEASE OR INABILITY TO RELEASE ANY EXTERNAL STORE, CARGO, OR LOAD. 1.2 PREWAD LOCKING SiW SHALL NOT BE USED IN THE FOLLOWING APPLICATIONS: 1.2.1 AT JOINTS IN CONTROL SYSTEMS AT SINGLE ATTACHMENTS OR WHERE LOSS OF THE THREADED PART WOULD WFECT SAFETY OR FLIGHT (EXCEPT AS NOTED IN 1.1.2). 1.2.2 ON
9、ANY EXTERNALLY THREADED PART THAT SERVES AS AU AXIS OF ROTATION FOR ANOTHER PART (EXCEPT AS NOTED IN 1.1.3). EXAMPLE: PULLEYS, CRANKS, LEVERS, LINKAGES, HINGE PINS AND CAM FOLLOWERS. 1.2.3 WITH BOLTS, SCREWS OR OTHER THREADED PARTS ON JET ENGINE AIRCRAFT, WITHIN LOCATIONS WHERE, IN THE EVENT THAT HA
10、RDWARE BECOMES LOOSE, THE NUT, BOLT OR SCREW, OR OTHER THREADED PART COULD BE DRAWN INTO THE ENGINE AIR INTAKE DUCT. 1.2.4 WITH BOLTS, SCREWS, STUDS OR OTHER THREADED PARTS TO ATTACH ACCESS PANELS, WORS OR ANY PARTS THAT ARE ROUTINELY DISASSEMBLED PRIOR TO OR AFTER EACH FLIGHT. 1.3 THE BOLT, SCREW O
11、R STUDS OR OTHER EXTERNALLY THREADED PARTS SHALL BE FLUSH OR EXTEND BEYOND THE TOP OF THE NUT AFTER INSTALLATION. INSTAUATION TORQUE SHALL CONFORM TO THE APPLICABLE PART DRAWING OR STANDARD. 1.4 DESIGN STANDARD FOR USE WITH MIL-N-Sf7.57, ITLE .A (FASTENERS) INTERNALLY THREADED, PRELU4D M Il IT ARY ST AH DA RD .A, IAVY -AS khrrh LOCKING, 450F. BOOOF, 1200P, RELIABILITY AND MINTAINABILITY DESIGN REQUIREMENTS FOR MS 14194 ISAF - * rRMY - MI Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
