1、MIL-N-85729 7 March 1988 MILITARY SPECIFICATON NUT, SELF-LOCKING, A-286, 160 ksi Ft.u, 450F, GENERAL SPECIFICATION FOR * This specification is approved for use by al 1 Departments and Agencies of the Department of Defense. l. SCOPE 1.1 Scope. This specification covers self-locking A-286 corrosion re
2、sistant nuts for use in temperatures up to and including 450F, in conjunction with expandable shank bolts conforming to MIL-B-85667. 2. APPLICABLE DOCUMENTS 2.1 Government documents. 2.1.1 Specifications and standards. The following specifications and standards from a part of this specification to t
3、he extent specified herein. Unless otherwise specified, the issues of these documents shall be those 1 isted in the issue of the Department of Defense Index of Specifications and Standards (DODISS) and supplement thereto, cited in the solicitation. 0 SPECIFICATIONS FEDERAL QQ-P-35 Passivation Treatm
4、ents for Corrosion Resisting Steel PPP-H-1581 Hardware (Fasteners and Related Items) Packaging and Packing for Shipment and Storage of Beneficial comments (recommendations, additions, deletions) and any pertinent data.which may be of use in improving this document should be addressed to - the Naval
5、Air Engineering Center, Systems Engineering and Standardization Department (Code 531, Lakehurst, NJ 08733-5100, by using the self-addressed Standardization Document Improvement Proposal (DD Form 1426) appearing at the end of this document or by letter. AMSC NIA FSC 5310 DISTRIBUTION STATEMENT A. App
6、roved for public release; distribution is ynlimited. Y T THIS DOCUMENT CONTAINS u PAGES. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-N-85729 SPECIFICATIONS (continued) MILITARY MIL-H-6875 MIL-S-8879 MIL-W-8982 MI L-L-8937 STAWARDS HELETARY MI
7、C-STD-I05 MIL-STD-129 MI L-STD-41 O MI C-STD- 1 3 1 2 MIL-STD-6866 MS33588 MS33787 Heat. Treatment of Steel- (Aircraft Practice), Process for Screw Threads, Control led Radius Root with Increased Mi nor Di ameter, General Specif i cation for Wrenches, Spl ined, High Strength, Thin Wal 1, General Spe
8、cification For- Lubricant, SoTid Film, Heat Cured, Corrosion Enhibiting, Nato-ode Number, S-1738 Sampling Procedures and Tables for Inspection by Attributes Marking far Shipment and Storage Non-Destructive TesEing Personnel Qualification and Cer t i f icat i OR Fastener, Te-st Nethods Inspecion, Liq
9、uid Penetrant Nut, Self-Lock ng, Aircraft, Design and Usage Requirements For Wrenching El-ement, External Spline, Dimensions For (Copies of specifications, standards, handbooks, drawings and publications and other Government documents required by contractors in connection with specific. acquisition
10、functions should be obtained from the contracting activity or as directed. ) 2.2 Other publications. The following docume,nt(s) forms a part of this specification to the extent specified herein. Unless otherwise specified, the issues of the documents which are DoD adopted shall be those 1 i sted in
11、the issue of the DoDISS specified in the sdicitation. Unless otherwise specified, the issues of documents not 1 isted in the DODISS shall be the issue of the nongovernment documents which is current on the date of the solicitation. AMERICAN NATIONAL STANDARDS INSTITUTE (ANSI) ANSI B46.1 Surface Text
12、ure (Surface Roughness, Waviness and Lay) (Application for coples should be addressed to the American Standards Institute, 1430 Broadway, New York, NY 10018.) Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,- MIL-N-B5729 53 W 9999906 O112470 T W MIL-N
13、-85729 SOCIETY OF AUTOMOTIVE ENGINEERS, INC. (SAE) AMS 5525 Steel, Sheet, Strip Where A = Cross sectional area (Sq-In.) per NAS 1348. Area based on maximum pitch diameter of bolt thread. Ftu = 160 KSI Ha = Axial Strength (lbs.) TABLE II. Stress Durability and Stress Corrosion. Nominal Nominal Grip S
14、ize Length of Bolt (In.) -1900-32 2.75 .8750-14 2.75 .7 500- 1 6 2.75 .6250-18 2.50 ,5625-18 2.50 .5000-20 2.50 .4375-20 2 .o0 -3750-24 2 .o0 -31 25-24 2 .O0 -2500-28 2 .o0 1 .oooo-12 3.00 1.1250-12 3 .O0 1 .2500-12 3 .O0 1 .3750-12 3 .O0 1 -5000-1 2 3.00 Bolt -Elongation (In.) ,0049 .0052 ,0053 . .
15、O056 . O068 .0070 .0073 .O08 1 ,0084 .0088 .0096 .0100 , O1 03 . O1 06 . o1 o9 5 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MI L-N-85729 (a).Test bolt-shall be stressed by torquing the nut until elongation is within 0.0005 of value specified. Th
16、is elongation will indicate a stress of 50% of the minimum axial strength. (b) Bolt elongations awcalculated usi.ng bushing assembly lengths “A“ (dimensions “L“ per table VIII). (c1 Other bolt grip lengths permissible. Calculate elongation per MIL-STD-1312-14, using values for “A“ equal to nominal g
17、rip length plus three times the thread pitch, TABLE. III. Torque Values. Nomi na1 Size .19(30-32 ,2500-28 3125-24 .3750-24 .4375-20 -5000-20 .5625-18 -6250-1 8 -7500- 1 6 8750-1 4 1 . 0000- T 2 1.1250-12 1.2500-12 1 -3750-1 2 1.5000-1 2 - 1/ Values Seat i ng Torquc For Torque Effectivity Test (In-Lb
18、s. 1 56 130 2 90 480 700 980 1,360 T, 780 3,020 4,980 6,840 8,870 TO, 840 12,800 14,400 2 Maxi mum Lock Room Temperature (In-Lbs. ) 18 30 60 80 1 O0 1 50 200 300 400 600 800 900 1,000 1,100 1,250- g Torques i/. Room Temperature After Bake (In-Lbs. 1 36 60 120 160 200 300 400 600 800 1,200 1,600 1,80
19、0 2,000 2,200 2,500 T kpply to nuts as 1 ubricated by manufacturer. 6 Mi nimm Breakaway Torque (In-Lbs. 1 2.0 3.5 6 5- 9.5 14.0 18.0 24 .o 32.0 50.0 70.0 90.0 117.0. 143.0 165.0 195.0 Assembly Torque Vi brat i on 32 53 107 142 177 2 67 356 533 SEE 4.5.4.1 “I Provided by IHSNot for ResaleNo reproduct
20、ion or networking permitted without license from IHS-,-,-MIL-N-85727 53 999770b OLL2q74 7 * MIL-N-85729 3.14 Stress corrosion. The nuts shall show no evidence of cracking when tested as specified in 4.5.6. 3.15 Discontinuities, Discontinuities in the nuts shall not exceed the depth limitations shown
21、 in table IV, see 4.5.7. Care shall be exercised not to confuse cracks with discontinuities, see 6.4.3. Cracks are not permitted in any location. TABLE IV. Nomi na1 rhread Si ze .1900-32 .2500-28 .3125-24 -3750-24 .4375-20 .5000-20 .5625-18 .6250- 18 ,7500-1 6 .8750-l4 1 .oooo-12 - 1 .1250-12 l. 250
22、0-1 2 1.3750-12 1 .5000-12 Discontinuity Depth Limits, Maximum, Inch 11. Limits .O05 .O05 ,005 .O06 ,007 .O08 .O08 .O08 .O08 .O08 .O08 .O08 ,008 .O08 .O08 “ L Rejectable Cri teria Any crack, regardless of location. Discontinuties in excess of specified limits. - 11 Samples of nuts having indications
23、 may be sectioned and micro-examined to determine whether the indications are due to tool or die marks, or due to discontinuities, and to determine conformance of discontinuities to the depth limits specified in table IV. 3.16 Heat treatment. The nuts and washers shall be heat treated in accordance
24、with MIL-H-6875 to develop the mechanical properties as specified herei n. 3.17 Workmanship. Workmanship shall be consistent with the type or product, finish, and the class of thread fit specified. Sharp edges shall be broken; hanging burrs and sl ivers shall be removed. 4. QUALITY ASSURANCE PROVISI
25、ONS 4.1 Responsibility for inspection. Unless otherwise specified in the contract or purchase order, the contractor is responsible for the performance of all inspection requirements as specified herein. Except as otherwise specified in the contract or purchase order, the contractor may use his own o
26、r any other facilities sui table for the performance of the inspection requirements specified herein, unless disapproved by the Government. The Government reserves the right to perform any of the inspections set forth in the specification where such inspections are deemed necessary to assure suppl i
27、es and servi ces conform to prescribed requirements. O Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-t MI L-N-85729 4.2 Classification of inspections. The inspection requirements specified herein are classified as foTlows: a. Qualification Inspecti
28、on (4.3) b. Quati ty Cotiformance Inspection (4.4) 4.3 Qualification inspection, 4.3.1 Sample Qualification est samples (see table V) shall consist of 50 nuts for each size upon which qualification is desired. All bolts, screws, and mandrels necessary for tesEs specified herein shall be furnished by
29、 the manufacturer. Complete description and name of lubricating material used on the nuts shall be furnished. Samples shaTl be identified as required and forwarded to the activity responsible for qualification designated in the letter of authorization from that activity, see 6.3. TABLE V. Qualificat
30、ion test plan. Test Paragraph Exami nation of Product 4.5.1 Thread Fit 4.5.1 Bearing Surface Squweness 4.5.1.1 Axial Strength Wrench Torque Torque Effecti vi ty , Room Temp (Locki ng El ement 1 Torque Effectivity, 450F (Locking Element) Locki ng Torque Permanent Se Stress Corrosion Rccelerated Vibra
31、tion Stress Durabi T i ty Discontinuities 4.5.2 4.5.31 4.5.3.2 4.5.3.2. T 4.5.3.3 4.5.3.4 4.5.6 4.5.4 4.5.5 4.5.7 Required Required Al 1 Al 1 3 5 5 5 5- 3 3 6 5 6 Al 1 O o O 5 5 5 4.3.2 Inspections The qualification inspections shall consist of all tests and examinations specified in 4.5. te th re 4
32、.3.3 Certified test report. The manufacturer shall furnish a certified st report showing that the manufacturers product satisfactorily conforms to is specification. The test report shall include, as a minimum, actuaT sults of the tests specified herein. When this report is submitted, it shall be acc
33、omDanied by a dated drawing which describes the manufacturer I S inent dimensions and tolerances, composition of luded on the above drawing. and the heat treat. The manufacturers part number product by speci f) material selected, for each size shal fing pert coat i ng 1 be inc the Provided by IHSNot
34、 for ResaleNo reproduction or networking permitted without license from IHS-,-,-MI L-N-85729 * 4.3.4 Retention of qualification. Certification shall be requested by the Naval Air Development Center (NAVAIRDEVCEN), Code 6013, Marminster, PA 18974, from each manufacturer. NAVAIRDEVCEN will forward cer
35、tification to the Naval Air Engineering Center (NAVAIRENGCEN), Code 5311, who is acting as agent for the Naval Air Systems Command (NAVAIR), AIR-53033G). Certification shall be at the time of the two year review and shall be signed by a responsible official of management, attesting that the listed p
36、rsduct(s1 is still available from the listed plant, can be produced under the same conditions as originally qualified; (i.e., same process, materials, construction, design, manufacturers part number, or designation); and meets the requirements of the current issue of the specification. Failure to pr
37、ovide the certification will be cause for removal from the QPL. After completion of the certification review, the QPL will be reprinted to show the date of certification. (DD Form 1718, Certification of Qualified Products, shall be used for obtaining certification.) 4:4 Quality conformance inspectio
38、n. The quality conformance inspections shall consist of those examinations and tests listed in 4.4.2 on samples selected in accordance with sampling plans A, B, and C. 4.4.1 Selection of samples. Sample nuts shall be selected at random from each inspection lot as specified herein. 4.4.1.1 Inspection
39、 lot. A lot shall consist of finished nuts of the same type and diameter fabricated by the same process, from one heat of material, heat treated in the same manner, and produced as one continuous run, order, or part thereof. O 4.4.1.2 Sampling Plan A. Sampling sizes for examination of product and th
40、read fit (4.5.1) and bearing surface squareness (4.5.1.1) shall be in accordance with MIL-STD-105, inspection level S-1, as specified in table VI. The acceptance and rejection criteria shall be applied to the following acceptance quality levels (AQLs) pertaining to the corresponding class of charact
41、eristics: Major AA Major A Major B Major C Major D 0.0 percent 0.4 percent 1.5 percent 2.5 percent 4.0 percent 4.4.1.2.1 Classification of defects. The classification of defects for self-locking nuts shall be: Major AA Visual inspection of package marking. Major A Visual presence of locking configur
42、ation. Bearing surface squareness. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Lot Size Jnder 26 26 thru 50 51 thru 90 91 thru 150 151- thru 280 281 thru 500 501 thru 1,200 1,201 thru 3,200 3,201 thru 10,000 10,001 thru 35,000 )ver 35,000 MIL-N-8
43、5729 Major B Thread Fi t Major C Wrench Size - Height of wrenchable portion. Overall Height - Diameter of bearng surface. Loose or hanging burrs - Concentricity of threads to base diameter. All dimensional characteristics not covered above. Kajor D Part identification per applicable standard or dr a
44、wi trg . TABLE VI. Inspection Sampling Plan A I O. ;ample Size 25 32 32 32 32 32 T25 125 200 31 5 500 Ac - O O O O O O 1 1 2 3 5 - Re - 1 1 1 1 1 1 2 2 3 4 6 - 8 8 8 32 32 50 80 125 1 O0 31 5 500 - - AC AC O O O 1 1 2 3 5 7 1( 11 Re 1 1 1 2 2 3 4 6 8 11 1: Where sample size i S equal to or greater t
45、han lot 5 5 20 20 32 50 80 125 200 31 5 500 AQ Ac - O O 1 1 2 3 5 7 10 14 21 t 4. - Re - 1 1 2 2 3 4 6 8 11 1E 22 jamplf Size 3 13 13 20 32 50 80 125 200 31 5 31 5 size 100% inspect. Ac - O 1 1 2 3 5 7 IO 14 !1 ?1 1 4 6 8 11 15 22 22 Provided by IHSNot for ResaleNo reproduction or networking permitt
46、ed without license from IHS-,-,-MIL-N-85729 4.4.1.3 Sampling Plan B. For the axial strength test (4.5.21, locking torque test (4.5.3.31, and permanent set (4.5.3.4), the samples shall be selected in accordance with table VII. TABLE VI1 . Sampl i ng pl an B. I- l Lot Size 1 Sample Size 1 Acceptance N
47、umber 5 10 15 27 O o o 1 I I 4.4.1.4 Sampling Plan C. For stress durability (4.5.51, sample size shall be 5 for each lot and the acceptance number zero. 4.4.2 Tests. The qual i ty conformance tests shall consist of: a. Examination of Product (4.5.1 and 4.5.1.1) b. Axial Strength (4.5.2) c. Locking T
48、orque (4.5.3.3) d. Discontinuities (4.5.7) 4.5 Test methods. 4.5.1 Examination of product. The nuts shall be examined for conformance to this specification and applicable approved standards with respect to material , workmanship, dimensions, design and construction, and finish. 4.5.1.1 Bearing surfa
49、ce. After removal of washer from the nut bearing surface values shall be measured by means of a table squareness gage, with a seating surface diameter equal to or greater than the base diameter of the nut being examined, in conjunction with a feeler gage, with a class 3A threaded member at engagement in the locking device, and turned finger tight. 4.5.2 Axial strength. The nuts shall be assembled on test bolt
