1、Comments, suggestions, or questions on this document should be addressed to: Commander, Naval Sea Systems Command, ATTN: SEA 05Q, 1333 Isaac Hull Avenue, SE, Stop 5160, Washington Navy Yard DC 20376-5160 or emailed to CommandStandardsnavy.mil, with the subject line “Document Comment”. Since contact
2、information can change, you may want to verify the currency of this address information using the ASSIST Online database at http:/assist.daps.dla.mil. AMSC N/A FSC 5310 INCH-POUND MIL-DTL-32258 28 June 2007 SUPERSEDING MIL-N-25027/1A 28 April 1995 DETAIL SPECIFICATION NUT, SELF-LOCKING (RING TYPE NO
3、N-METALLIC INSERT), HEAVY HEX, CONTROLLED ROOT RADIUS, NICKEL-COPPER ALLOY This specification is approved for use by all Departments and Agencies of the Department of Defense. 1. SCOPE 1.1 Scope. This specification covers ring-type, self-locking, heavy hex, nickel-copper alloy nuts, with screw threa
4、ds with a controlled root radius for use in general shipboard applications. Coarse pitch series and eight pitch series of threads are covered by this specification. Nuts with a nominal diameter between and 2 inches are covered in this specification. 1.2 Classification. 1.2.1 Thread series. Self-lock
5、ing nuts have the following thread series: a. C - Coarse unified threads (UNJC) with a controlled root radius. b. 8 - Eight threads per inch unified threads (8-UNJ) with a controlled root radius. 1.2.2 Temperature rating. Self-locking nuts are of the following temperature ratings: a. A 250 F b. V 45
6、0 F 1.3 Part or identifying number (PIN). When specified (see 6.2), PINs to be used for ring-type, self-locking, heavy hex, nickel-copper alloy nuts acquired to this specification are created as follows: (see 1.3.1 through 1.3.4 for PIN Code designations) M Prefix Specification number Hyphen Lubrica
7、tion Temperature rating Thread series Nominal diameter M 32258 - U V C 04 The example above (M32258-UVC04) is for a 0.250-inch, 450 F, coarse graded pitch series, unlubricated nut. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-32258 1.3.1 L
8、ubrication. Nut lubrications are as follows: Lubrication PIN Code Lubricated L Unlubricated U 1.3.2 Temperature rating. Nut temperature ratings are as follows: Temperature rating PIN Code 250 F A 450 F V 1.3.3 Thread series. Nut thread series are as follows: Thread series PIN Code 8 constant pitch s
9、eries (UNCJ) 8 Coarse graded pitch series (8-UNJ) C 1.3.4 Nominal diameter. Nut nominal diameters are as follows: Nominal diameter (inches) PIN Code Nominal diameter (inches) PIN Code 0.250 04 1.125 18 0.312 05 1.250 20 0.375 06 1.375 22 0.500 08 1.500 24 0.625 10 1.750 28 0.750 12 2.000 32 0.875 14
10、 2.250 36 1.000 16 2.500 40 2. APPLICABLE DOCUMENTS 2.1 General. The documents listed in this section are specified in sections 3, 4, or 5 of this specification. This section does not include documents cited in other sections of this specification or recommended for additional information or as exam
11、ples. While every effort has been made to ensure the completeness of this list, document users are cautioned that they must meet all specified requirements of documents cited in sections 3, 4, or 5 of this specification, whether or not they are listed. 2 Provided by IHSNot for ResaleNo reproduction
12、or networking permitted without license from IHS-,-,-MIL-DTL-32258 2.2 Government documents. 2.2.1 Specifications, standards, and handbooks. The following specifications, standards, and handbooks form a part of this document to the extent specified herein. Unless otherwise specified, the issues of t
13、hese documents are those cited in the solicitation or contract. DEPARTMENT OF DEFENSE STANDARDS MIL-STD-792 - Identification Marking Requirements for Special Purpose Components MIL-STD-1916 - DoD Preferred Methods for Acceptance of Product (Copies of these documents are available online at http:/ass
14、ist.daps.dla.mil/quicksearch/ or http:/assist.daps.dla.mil or from the Standardization Document Order Desk, 700 Robbins Avenue, Building 4D, Philadelphia, PA 19111-5094.) 2.3 Non-Government publications. The following documents form a part of this document to the extent specified herein. Unless othe
15、rwise specified, the issues of these documents are those cited in the solicitation or contract. ASME INTERNATIONAL ASME B1.2 - Gages and Gaging for Unified Inch Screw Threads (DoD adopted) ASME B1.3M - Screw Thread Gaging Systems for Dimensional Acceptability - Inch and Metric Screw Threads (UN, UNR
16、, UNJ, M and MJ) (DoD adopted) ASME B1.15 - Unified Inch Screw Threads, (UNJ Thread Form) ASME B46.1 - Surface Texture, Surface Roughness, Waviness and Lay (DoD adopted) (Copies of these documents are available online at www.asme.org or from ASME International, 22 Law Drive, PO Box 2900, Fairfield,
17、NJ 07007-2900.) ASTM INTERNATIONAL ASTM B880 - Standard Specification for General Requirements for Chemical Check Analysis Limits for Nickel, Nickel Alloys, and Cobalt Alloys ASTM D4066 - Standard Classification System for Nylon Injection and Extrusion Materials (PA) (DoD adopted) ASTM D6456 - Stand
18、ard Specification for Finished Parts Made from Polyimide Resin ASTM E1473 - Standard Test Methods for Chemical Analysis of Nickel, Cobalt, and High-Temperature Alloys ASTM F812 - Standard Specification for Surface Discontinuities of Nuts, Inch and Metric Series (Copies of these documents are availab
19、le online at www.astm.org or from ASTM International, 100 Barr Harbor Dr., PO Box C700, West Conshohocken, PA 19428-2959.) NATIONAL AEROSPACE STANDARDS NASM 1312-8 - Fastener Test Methods - Method 8 Tensile Strength (DoD adopted) (Copies of this document are available from http:/www.aia-aerospace.or
20、g or from the Aerospace Industries Association of America, 1250 Eye Street, N.W., Suite 1200, Washington, DC, United States, 20005-3924.) 3 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-32258 SAE INTERNATIONAL SAE AS5272 - Lubricant, Solid
21、Film, Heat Cured, Corrosion Inhibiting Procurement Specification SAE AS8879 - Screw Threads - UNJ Profile, Inch Controlled Radius Root with Increased Minor Diameter (DoD adopted) (Copies of these documents are available online at www.sae.org or from SAE World Headquarters, 400 Commonwealth Drive, Wa
22、rrendale, PA 15096-0001.) 2.4 Order of precedence. In the event of a conflict between the text of this document and the references cited herein, the text of this document takes precedence. Nothing in this document, however, supersedes applicable laws and regulations unless a specific exemption has b
23、een obtained. 3. REQUIREMENTS 3.1 Design. The self-locking nut or nut element shall be a self-contained unit with an unreinforced polyamide or an unfilled polyimide locking ring. The threads shall conform to the UNJ thread profile. The locking device shall not operate by separate movement from the i
24、nstallation and shall not depend on pressure on the bearing surface for locking action. 3.2 Manufacturing process. Nuts may be produced by any manufacturing process using any bar, rod, or wire, that is capable of meeting the requirements of this specification. The bar, rod, or wire used to make a lo
25、t of nuts shall consist of material from one heat, form, size, that has been heat treated in the same furnace charge. Threads used for the locking feature may be displaced or deformed in any manner which produces self-locking nuts conforming to this specification. 3.3 Recycled, recovered, or environ
26、mentally preferable materials. Recycled, recovered, or environmentally preferable materials should be used to the maximum extent possible, provided that the material meets or exceeds the operational and maintenance requirements, and promotes economically advantageous life cycle costs. 3.4 Materials.
27、 3.4.1 Nut. The nut material shall conform to the chemical requirements of Table I. Nuts machined from barstock may be made from free machining bar, rod, or wire (see Table I). 3.4.2 Ring material. The locking ring on nuts with temperature rating A shall be in accordance with ASTM D6456, Type 1 or A
28、STM D4066 Group 1, Class 1 or 2, Grade 1, 2, 3, 4, 5, or 6. The nut locking ring on nuts with temperature rating B shall be in accordance with ASTM D6456, Type 1. 4 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-32258 TABLE I. Chemical compo
29、sition. Chemical Percent Chemical Percent Nickel + Cobalt 63 70 Sulfur 0.0151/Iron 2.50 (max) Copper Remainder Aluminum 0.5 (max) Lead 0.006 (max) Manganese 2.0 (max) Tin 0.006 (max) Cobalt 0.25 (max) Zinc 0.02 (max) Carbon 0.21/(max) Phosphorus 0.02 (max) Silicon 0.5 (max) NOTE: 1/Free machining ro
30、d, bar, and wire shall have and a sulfur content of 0.025 to 0.060 percent and a maximum carbon content of 0.3 percent. 3.5 Dimensions before the incorporation of the locking feature. 3.5.1 Nut dimensions. The width across flats and the width across corners shall be in accordance with the dimensiona
31、l requirements of Table II. 3.5.2 Bearing surface. The bearing surface shall be normal to the axis of the pitch diameter of the threads within the values shown in Table II (see 4.3.1.1.2). 3.5.3 Bearing surface roughness. The bearing surface roughness average shall be no greater than 125 microinches
32、 (see 4.3.1.1.3). 3.5.4 Threads. The threads shall meet the thread profile, dimensions, and tolerances of ASME B1.15, with Class 3B threads, or SAE AS8879, Category 1. The thread profile, dimensions, and tolerances in SAE AS8879 are identical to and interchangeable with the thread profile, dimension
33、s, and tolerances for ASME B1.15, with Class 3B threads. 3.6 Dimensions after the incorporation of the locking feature. 3.6.1 Nut dimensions. The threaded length, overall nut height, and the wrenching flat height shall be in accordance with the dimensional requirements of Table II. 3.6.2 Threads. Th
34、e nut, after incorporation of the locking feature and prior to lubrication, shall allow the GO gage to enter not less than half a turn. 5 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-32258 TABLE II. Dimensional requirements of nuts. Nomina
35、l diameter (L) Threaded length1/(H) Overall nut height (F) Width across flats2/(G) Width across corners3/(B) Wrenching flat height4/(A) Bearing surface squareness Inches Inches Inches Inches Inches Inches Inches Threads per inch min max min max min min min max 0.250 20 0.230 0.390 0.360 0.504 0.492
36、0.552 0.290 0.005 0.312 18 0.260 0.453 0.423 0.566 0.553 0.622 0.335 0.006 0.375 16 0.354 0.562 0.532 0.692 0.679 0.766 0.392 0.006 0.500 13 0.482 0.718 0.688 0.880 0.865 0.978 0.544 0.007 0.625 11 0.593 0.874 0.844 1.068 1.052 1.191 0.677 0.008 0.750 10 0.761 1.015 0.985 1.257 1.239 1.403 0.790 0.0
37、09 0.875 9 0.872 1.140 1.110 1.446 1.427 1.615 0.883 0.010 1.000 8 0.920 1.312 1.250 1.634 1.614 1.826 1.000 0.012 1.125 7 1.038 1.469 1.407 1.822 1.801 2.038 1.096 0.013 1.250 7 1.190 1.672 1.610 2.011 1.973 2.232 1.250 0.014 1.375 6 1.328 1.828 1.766 2.200 2.159 2.444 1.376 0.015 1.500 6 1.376 1.9
38、53 1.891 2.388 2.344 2.622 1.413 0.016 1.750 5 1.707 2.376 2.250 2.766 2.715 3.075 1.630 0.018 2.000 4 1.816 2.469 2.343 3.142 3.086 3.497 1.750 0.020 2.250 4 2.073 2.876 2.780 3.518 3.457 3.918 2.063 0.020 2.500 4 2.381 3.204 3.078 4.020 3.875 4.393 2.475 0.020 NOTES: 1/The tapped hole shall be cou
39、ntersunk on the bearing surface. The maximum countersink diameter shall be equal to the nominal diameter plus 0.030 for 0.375 nominal diameter nuts and smaller, and 1.08 times the nominal diameter for nuts larger than a 0.375 nominal diameter. No part of the threaded portion shall project beyond the
40、 bearing surface. The measurement of the dimension (L) shall include effective length of the thread engagement, and one countersunk height at the bearing surface. The dimension (L) shall not include the self-locking insert height. 6 Provided by IHSNot for ResaleNo reproduction or networking permitte
41、d without license from IHS-,-,-MIL-DTL-32258 TABLE II. Dimensional requirements of nuts. Continued. NOTES: 2/The minimum width across flats applies only to transverse sections through the nut between 25 percent and 75 percent of the height of the wrenching flat, measured from the bearing surface. 3/
42、A rounding or lack of fill at the junction of the hex corners with the bearing surface chamfer shall be permissible provided the width across the corners is within specified limits at and beyond a distance equal to 17.5 percent of the nominal diameter from the bearing surface.4/The diameter of the b
43、earing surface chamfer circle shall be within the limits of the maximum width across the flats and 95 percent of the minimum width across the flats.3.7 Axial tensile strength. The nuts shall have a minimum axial tensile strength as specified in Table III. 3.8 Locking torque. The torque required for
44、installation and/or removal shall not be greater than the maximum locking torque values specified in Table III (see 4.4.3). The torque required to start the unseated nut in the removal direction shall not be less than the minimum breakaway torque values specified in Table III (see 4.4.3). TABLE III.
45、 Mechanical property test requirements. Nominal diameter Minimum axial strength Maximum locking torque Minimum breakaway torque Inches Pounds FootPounds FootPounds 0.250 6,000 30 4.5 0.312 8,600 60 7.5 0.375 12,700 80 12.0 0.500 24,800 150 24.0 0.625 38,300 300 40.0 0.750 54,000 400 60.0 0.875 73,00
46、0 600 82.0 1.000 95,800 800 110.0 1.125 121,100 900 137.0 1.250 146,600 1,000 165.0 1.375 186,000 1,200 200.0 1.500 200,000 1,400 230.0 1.750 205,000 1,800 300.0 2.000 233,000 2,200 360.0 2.250 390,000 2,600 430.0 2.500 500,000 3,000 500.0 3.9 Permanent set. The nuts shall meet the minimum breakaway
47、 torque requirements on minimum material condition bolts or studs, subsequent to installation on maximum material condition bolts or studs, when tested in accordance with 4.4.3.2. The nuts shall not exceed the maximum locking torque nor be below the minimum breakaway torque values specified in Table
48、 III when subjected to this test. 3.10 Discontinuities. Discontinuities shall not be greater than permitted in 4.4.5. Cracks, clean crystalline breaks passing through the grain or grain boundary without the inclusion of foreign elements, are not permitted. 7 Provided by IHSNot for ResaleNo reproduct
49、ion or networking permitted without license from IHS-,-,-MIL-DTL-32258 3.11 Manufacturers identification. Nuts shall be marked on the wrenching surface with the manufacturers identification symbol, material symbol, and the lot number. Nuts with a temperature rating of 250 F shall be marked with material symbol “NICU”. Nuts with a temperature rating of 450 F shall be m
