1、NASM 7873-2000 Nut, Self-locking, 1200 Degree F_NATIONAL AEROSPACE STANDARD Q COPYRIGHT 2000 AEROSPACE INDUSTRIES ASSOCIATION OF AMERICA, INC. ALL RIGHTS RESERVED NASM7873 SPECIFICATION NUT, SELF-LOCKING, 1,200F 1. SCOPE 1.1 This specification covers self-locking nuts and self-locking plate nuts for
2、 use where temperatures will not exceed 1,200OF. 2. APPLICABLE DOCUMENTS 2.1 Government documents 2.1.1 SDecification and standards. Unless otherwise specified, issues of referenced documents are those in effect at the time of solicitation. Information regarding the latest issue of government docume
3、nts and adopted non-government documents can be obtained from the Department of Defense Index of Specification and Standards. SPECIFICATIONS Federal GGG-W436 GGG-W-641 PPP-H-1571 Military MIL-S-8879 STANDARDS Military AN503 MIL-STD-105 MIL-STD-129 MIL-STD-410 MIL-STD-1312 MIL-STD-1312-7 MIL-STD-1312
4、-8 Wrenches, Box and Open End (Nonadjustable) Wrench, Sockets (and Sockets, Handles, and Attachments for Socket Wrenches; Hand) Hardware (Fasteners And Related Items) Packing Of Screw Threads, Controlled Radius Root with Increased Minor Diameter, General Specification for Screw, Machine, Drilled, Fi
5、llister Head, Coarse Thread Sampling Procedure and Tables for Inspection by Attributes Marking for Shipment and Storage Nondestructive Testing Personnel (Qualification and Certification) Fastener, Test Methods Fastener, Test Method, Vibration Fastener, Test Method, Tensile Strength MIL-STD-1312-10 F
6、astener, Test Method, Stress Rupture MIL-STD-6866 Inspection, Liquid Penetrant MS20500 Nut, Self Locking, Hexagon, 1200f, 125 KSI Ftu MS20501 Nut, Self Locking, Plate, Two Lug, 120of, 125 KSI Ftu (Copies of specifications, standards, drawings, and publications required by suppliers in connections wi
7、th specific procurement functions should be obtained from the procuring activity or as directed by the contracting officer.) THE INITIAL RELEASE OF THIS DOCUMENT SUPERSEDES MIL-N-7873, REVISION B, AMENDMENT 1. LIST OF CURRENT SHEETS NO111213(4(516)71819) 10 REV I NEW I NEW I NEW I NEW I NEW I NEW I
8、NEW I NEW I NEW I NEW SHEET 1 OF 10 FSC 5310 APPROVAL DATE MARCH 2000 USE OF OR RELIANCE UPON THIS DOCUMENT OR ANY NATIONAL AEROSPACE STANDARD IS ENTIRELY VOLUNTARY. AIA DOES NOT QUALIFY SUPPLIERS OR CERTIFY CONFORMANCE OF ITEMS PRODUCED UNDER NATIONAL AEROSPACE STANDARDS. AIA MAKES NO REPRESENTATIO
9、N OR CLAIM RESPECTING (1) THE SUITABILIPI OF ITEMS FOR ANY PARTICULAR APPUCATION, OR (2) THE EXlSTENCE OF OR APPLICABILITY THERETO OF PATENT OR TRADEMARK RIGHTS. REVISION COPYRIGHT Aerospace Industries Association of America, Inc. (AIA/NAS)Licensed by Information Handling ServicesSTD.AIA/NAS NASM787
10、3-ENGL 2000 EU 0338743 0508765 950 m NATIONAL AEROSPACE STANDARD Q COPYRIGHT 2000 AEROSPACE INDUSTRIES ASSOCIATION OF AMERICA, INC. ALL RIGHTS RESERVED NASM7873 2.2 Other Dublications. Unless otherwise specified, issues of the referenced documents are those in effect at the time of solicitation. Inf
11、ormation regarding the latest issue of nongovernment documents not adopted by the government can be obtained from the organization responsible for their publications. American Societv of Mechanical Enaineers. ASME 846.1 Surface Texture (Surface Roughness, Waviness and Lay) (Copies of the above publi
12、cation may be obtained from the American Standards Association, Inc., 1 O East 40th Street, New York, N.Y. 10016.) Societv of Automotive Enaineers (Aerospace Material SDecifications) AMS 241 1 Silver Plating, For High Temperature Applications (Copies of SEA publications may be obtained from the Soci
13、ety of Automotive Engineers, Inc., 400 Commonwealth Drive, Warrendale, PA 15068-0001. American Societv for Testina and Materials (ASTM) ASTM A342 Standard Test Method For Permeability of Feebly Magnetic Materials. (Application for copies should be addressed to the American Society for Testing and Ma
14、terials 1916 Race St. Philadelphia, Pa. 19103. 3. REQUIREMENTS 3.1 Militarv standards. The individual item requirements shall be as specified herein and in accordance with the applicable standards. In the event of a conflict between requirements of this specification and the standard, the latter sha
15、ll govern. 3.2 Qualification. The nut manufacturer shall be responsible for conducting qualification tests and furnishing part drawings, certified qualification test reports (if required by the purchaser) and test samples. The nuts furnished under this specification shall be produced using the same
16、manufacturing methods as those used to produce nuts that have passed qualification tests. The purchaser may apply any or all tests specified herein to any product represented as meeting this specification, at any time, to verify conformance. 3.2.1 Retention of Qualification. Requalification will be
17、required in the event any change is made in the product design, construction, materials, method of manufacture, heat treatment, finish, lubricant, or manufacturers part number or designation. 3.3 Materials. Nuts shall be fabricated from heat-resisting and corrosion-resisting austenitic steel which i
18、s not subject to intergranular deterioration at 1,200F f 25F. In the event the applicable standard drawing specifies a particular material for fabrication of the nuts, the specified material shall be used. 3.4 Desian. Self-locking nut design shall conform to the applicable standard. 3.5 Construction
19、. The self-locking nut element shall be a self contained, all metal unit, including the self-locking device. The locking device shall be of the prevailing torque type and shall not operate by means of separate movement from the installation and shall not depend upon pressure on the bearing surface f
20、or locking action. 3.5.1 Bearing surface. The bearing surface shall be normal to the axis of the thread pitch cylinder of the threads within ,003 inch full indicator reading for sizes up to ,5000 inch, and within .O05 inch for sizes larger than 5000 inch (see 4.5.1.1). The wrenching surface circular
21、 runout to the thread pitch cylinder shall be within .O10 inch full indicator movement. 3.5.1 .i The bearing surface roughness average of the nuts shall not exceed 125 microinches (Ra) in accordance with ASME 846.1 (see 4.5.1.2). 3.5.2 Threads.- Unless otherwise specified, the threads shall be in co
22、nformance with MIL-S-8879 prior to incorporation of the locking feature. Threads used on the locking device may be displaced or deformed in any manner which provides self-locking nuts conforming to this specification. After incorporation of the locking feature, the nut shall allow the go gage to ent
23、er a minitnum of 1.5 turns before engagement of the locking element. 3.5.3 Plate nut rivet-bolt hole alianment. Plate nut rivet-bolt hole alignment shall be in accordance with the applicable standard (see 4.5.1.3). 2 APPROVAL DATE MARCH 2000 REVISION QUALIFY SUPPLIERS OR CERTIFY CONFORMANCE OF ITEMS
24、 PRODUCED UNDER NATIONAL AEROSPACE STANDARDS. AIA MAKES NO USE OF OR RELIANCE UPON THIS DOCUMENT OR ANY NATIONAL AEROSPACE STANDARD IS ENTIRELY VOLUNTARY. AIA DOES NOT OR APPLICABILITY THERETO OF PATENT OR TRADEMARK RIGHTS. REPRESENTATION OR CLAIM RESPECTING (1) THE SUITABILITY OF ITEMS FOR ANY PART
25、ICULAR APPLICATION, OR (2) THE EXISTENCE OF COPYRIGHT Aerospace Industries Association of America, Inc. (AIA/NAS)Licensed by Information Handling ServicesSTD.AIA/NAS NASM7873-ENGL 2000 0338743 0508766 897 W NATIONAL AEROSPACE STANDARD Q COPYRIGHT 2000 AEROSPACE INDUSTRIES ASSOCIATION OF AMERICA, INC
26、. ALL RIGHTS RESERVED NASM7873 3.6 Platina and surface treatment. The threads shall be silver plated in accordance with AMS 241 l. Nominal thread size .2500 Nominal thread size under ,2500 inch shall show .O003 to ,0005 inch thick silver plate on bearing surface. Silver plate shall be inch and large
27、r shall show a minimum of .O002 inch thick silver plate on thread flank and show compiete coverage of threads. optional on other areas except, no plating shall be applied in the area of the projecting weld nibs of weld plate nuts. 3.7 Mechanical ProDerties 3.7.1 Axial tensile strenath. The nuts shal
28、l have a minimum axial tensile strength of not less than the values specified in table I, when tested as specified in 4.5.2. 3.7.2. Stress ruDture tensile strenath. Nuts shall withstand the tensile load specified in table I, when tested at elevated temperature as specified in 4.5.2. TABLE 1. Minimum
29、 strength requirements Thread size ,1380-32 .1640-32 ,1900-32 .2500-28 .3125-24 .3750-24 .4375-20 .5000-20 .5625-18 .6250-18 .7500-16 ,8750-14 1 .oooo-12 3.7.3 Toraue Axial strength At room temp (lbs. min.) 1,130 1,720 2,460 4,580 7,390 1 1,450 15,450 21,110 26,81 O 34,130 50,020 68,440 92,180 Axial
30、 strength after baking at 1,200F for 6 hours (lbs. min.) 850 1,290 1,840 3,430 5,500 8,600 11,600 15,800 20,l O0 25,600 37,500 51,300 69,100 Stress rupture Tensile load 96 hours at i ,200F (lbs. min.) 940 1,710 2,730 4,130 5,580 7,520 9,540 12,000 17,600 23,900 32,000 3.7.3.1 Wrench toraue. Wrenchab
31、le nuts shall withstand the wrench torque listed in table II (see 4.5.3.1). There shall be no permanent deformation that may interfere with the use of a box or socket wrench conforming to GGG-W-636 and GGG-W-641, respectively. TABLE II. Wrench toraue at room temp. after 6-hour (+25 hr -.O00 hr) bake
32、 at 1,200F f 25F Wrench torque Size Inch-Pounds ,1380-32 .1640-32 .1900-32 ,2500-28 .3125-24 .3750-24 .4375-20 ,5000-20 .5625-18 .6250-18 .7500-16 .8750-14 1 .oooo-12 20 30 60 150 360 650 1,200 1,600 2,300 4,000 6,000 8,000 11,000 TABLE 111. Maximum lockina and minimum breakawav toraue values. 3 APP
33、ROVAL DATE MARCH 2000 REVISION USE OF OR RELIANCE UPON THIS DOCUMENT OR ANY NATIONAL AEROSPACE STANDARD IS ENTIRELY VOLUNTARY. AIA DOES NOT QUALIFY SUPPLIERS OR CERTIFY CONFORMANCE OF ITEMS PRODUCED UNDER NATIONAL AEROSPACE STANDARDS. AIA MAKES NO OR APPLICABILITY THERETO OF PATENT OR TRADEMARK RIGH
34、TS. REPRESENTATION OR CLAIM RESPECTING (1) THE SUITABILITY OF ITEMS FOR ANY PARTICULAR APPLICATION, OR (2) THE EXISTENCE OF COPYRIGHT Aerospace Industries Association of America, Inc. (AIA/NAS)Licensed by Information Handling Services STD.AIA/NAS NASM7873-ENGL 2000 m 0318743 05087b7 723 NATIONAL AER
35、OSPACE STANDARD O COPYRIGHT 2000 AEROSPACE INDUSTRIES ASSOCIATION OF AMERICA, INC. ALL RIGHTS RESERVED Thread size Locking torque (in- lbs.) (installation or removal .i 380-32 UNJC .1640-32 UNJC .1900-32 UNJF 18 ,2500-28 UNJF .3125-24 UNJF .3750-24 UNJF .4375-20 UNJF .5000-20 UNJF .5625-18 UNJF .625
36、0-18 UNJF .7500-16 UNJF .8750-14 UNJF .OOOO-12 UNJF 30 60 80 1 O0 150 200 300 400 600 800 Minimum Breakaway torque (in- lbs.) 15th removal 1 .o I .5 2.0 3.5 6.5 9.5 14.0 18.0 24.0 32.0 50.0 70.0 90.0 NASM7873 3.7.3.2 Lockinq toraue 3.7.3.2.1 Maximum lockina toraue. Observe the maximum locking toque
37、during installation and the maximum torque during the removal cycle. The torque for installation or removal shall not exceed the values specified in table 111 when tested at room temperature. After baking at 1 ,20OoFk25F. the maximum locking toque of the nut shall not exceed twice the value specifie
38、d in table 111. (see 4.5.3.2). 3.7.2.2 Minimum breakaway toraue. The torque required to start unloading the nut in the removal direction shall be measured and shall not be less than the values specified in table 111. (see 4.5.3.2). 3.7.3.2.3 Reusabikf. Unless otherwise specified, nuts shall be capab
39、le of 15 unloaded installation and removal cycles without damage to the nut. (see 4.5.3.2.3). 3.7.3.3 Toraue out. Torque out values for plate nuts shall be not less than the values listed in table IV. (see 4.5.3.3). The nut or assembly shall conform to the values specified without cracking the nut r
40、etainer. The nut shall not become malformed sufficiently to preclude the application of the same torque in the opposite direction. TABLE IV. Toraue out I Thread size Torque (inch- pounds) ,1380-32 I 30 ,1640-32 ,1900-32 ,2500-28 .3125-24 ,3750-24 240 3.8 Push out. Push out values for the plate nuts
41、shall be not less than the values listed in table V. (see 4.5.4). The minimum load required to push out the nut from the retainer of any plate nut shall be not less than the values specified in table V. Additionally, for any plate nut, the minimum load required to effect a pennanent deformation axia
42、l with the nut element of .O30 inch, measured at the thread centerline between the test plate and the base of the threaded element, shall be not less than the values specified in table V. 4 REVISION APPROVAL DATE MARCH 2000 USE OF OR RELIANCE UPON THIS DOCUMENT OR ANY NATIONAL AEROSPACE STANDARD IS
43、ENTIRELY VOLUNTARY. AIA DOES NOT QUALIFY SUPPLIERS OR CERTIFY CONFORMANCE OF ITEMS PRODUCED UNDER NATIONAL AEROSPACE STANDARDS. AIA MAKES NO REPRESENTATION OR CLAIM RESPECTING (1) THE SUlTABlLrrY OF ITEMS FOR ANY PARTICULAR APPLICATION. OR (2) THE EXISTENCE OF OR APPLICABILITY THERETO OF PATENT OR T
44、RADEMARK RIGHTS. COPYRIGHT Aerospace Industries Association of America, Inc. (AIA/NAS)Licensed by Information Handling ServicesNATIONAL AEROSPACE STANDARD COPYRIGHT 2000 AEROSPACE INDUSTRIES ASSOCIATION OF AMERICA, INC. ALL RIGHTS RESERVED NASM7873 TABLE V. Push out Thread size Torque (inch- ounds .
45、I 380-32 .1640-32 .1900-32 I O0 2500-28 and over 125 3.9 Vibration. Wrenchable and plate nuts shall show no evidence of failure when subjected to the vibration test (see 4.5.5). Vibration test on nuts larger than SOO inch thread size are waived, provided that nuts 300 thread sue and smaller of the s
46、ame type and design of locking device have p.assed the vibration test. Vibration testing is not required for sizes smaller than .1W. Vibration tests on plate nuts having locking devices identical to qualifed wrenchable nuts are waived. Plate nuts requiring vibration tests shall be vibrated after removal of plate lugs. 3.10 Discontinuities. Discontinuities in the nuts shall not exceed the depths shown in table VI when tested as specified in 4.5.6.
