1、AMSC N/A FSC 5306 INCH-POUND MIL-DTL-45912B 6 August 2013 SUPERSEDING MIL-B-45912A 8 August 1969 DETAIL SPECIFICATION BOLT, SELF-LOCKING, HEXAGON HEAD, STEEL INACTIVE FOR NEW DESIGN AFTER 6 August 2013 This specification is approved for use by all Departments and Agencies of the Department of Defens
2、e. 1. SCOPE 1.1 Scope. This specification covers one type of steel, hexagon head, self-locking bolt. 1.2 Classification. The bolt shall be furnished in the following compositions: Composition A SAE Grade 5 Composition B SAE Grade 8 2. APPLICABLE DOCUMENTS 2.1 General. The documents listed in this se
3、ction are specified in sections 3, 4, or 5 of this standard. This section does not include documents cited in other sections of this standard or recommend for additional information or as examples. While every effort has been made to ensure the completeness of this list, document users are cautioned
4、 that they must meet all specified requirements of documents cited in sections 3, 4, or 5 of this standard, whether or not they are listed. 2.2 Government documents. 2.2.1 Specifications, standards, and handbooks. The following specifications and standards form a part of this document to the extent
5、specified herein. Unless otherwise specified, the issues of these documents are those cited in the solicitation or contract. FEDERAL STANDARDS FED-STD-H28/2 Screw-Thread Standards for Federal Services Section 2 Unified Inch Screw Threads- UN and UNR Thread Forms FED-STD-H28/20 Screw-Thread Standards
6、 for Federal Services Section 20 Inspection Methods for Acceptability of UN, UNR, UNJ, M and MJ Screw Threads Comments, suggestions, or questions on this document should be addressed to Defense Supply Center Philadelphia (DSCP), ATTN: DSCP-NASA, 700 Robbins Avenue, Philadelphia, PA 19111-5096 or e-m
7、ail to dscpg&ispecommentsdla.mil . Since contact information can change, you may want to verify the currency of this address information using the ASSIST Online database at https:/assist.dla.mil . Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-D
8、TL-45912B 2 DEPARTMENT OF DEFENSE SPECIFICATIONS MIL-DTL-16232 Phosphate Coating, Heavy, Manganese or Zinc Base DEPARTMENT OF DEFENSE STANDARDS MS35763 Bolt, Self-Locking, Hexagon Head, Steel, Grade 5, UNC-2A and UNF-2A (Inactive for new design) MS35764 Bolt, Self-Locking, Hexagon Head, Steel, Grade
9、 8, UNC-2A and UNF-2A (Inactive for new design) (Copies of these documents are available online at https:/assist.dla.mil/quicksearch/ or from the Standardization Document Order Desk, 700 Robbins Avenue, Building 4D, Philadelphia, PA 19111-5094.) 2.3 Non-Government publications. The following documen
10、ts form a part of this document to the extent specified herein. Unless otherwise specified, the issues of these documents are those cited in the solicitation or contract. AMERICAN SOCIETY FOR QUALITY (ASQ) ASQ Z1.4 Sampling Procedures and Tables for Inspection by Attributes. (Copies of this document
11、 are available from www.asq.org American Society for Quality Control, 600 North Plankinton Avenue, Milwaukee, WI 53203.) SOCIETY OF AUTOMOTIVE ENGINEERS (SAE) SAE AMS-QQ-P-416 Plating, Cadmium (Electrodeposited) SAE-J429 Fasteners, Externally Threaded, Mechanical and Material Requirements for (Copie
12、s of these documents are available from www.sae.org or the Society of Automotive Engineers, Inc., 400 Commonwealth Drive, Warrendale, PA 15096-0001.) 2.4 Order of precedence. Unless otherwise noted herein or in the contract, in the event of a conflict between the text of this document and the refere
13、nces cited herein, the text of this document takes precedence. Nothing in this document, however, supersedes applicable laws and regulations unless a specific exemption has been obtained. 3. REQUIREMENTS 3.1 Material. The bolts shall conform to the material composition of SAE Grade 5 or Grade 8 in a
14、ccordance with SAE J429. Composition A SAE Grade 5 (MS35763) Composition B SAE Grade 8 (MS35764) 3.2 Design. The bolts shall conform to the design, dimensions and tolerances specified on MS35763 or MS35764 and in Figure 1 and Table I. 3.3 Protective finish. The bolts shall be cadmium plated or phosp
15、hate coated as specified on the applicable Military Standard. Cadmium plating shall conform to the requirements of Type II, Class 2 of SAE AMS-QQ-P-416. Zinc phosphate coating shall conform to the requirements of Type Z, Class 2 of MIL-DTL-16232. Provided by IHSNot for ResaleNo reproduction or netwo
16、rking permitted without license from IHS-,-,-MIL-DTL-45912B 3 FIGURE 1. Head Design. TABLE I. Head Dimensions. Nominal Size 1/4 5/16 3/8 7/16 1/2 9/16 5/8 3/4 7/8 1 1-1/4 B Recess Max Dia Min .166 .146 .208 .188 .250 .230 .288 .268 .332 .312 .374 .354 .416 .396 .500 .480 .584 .564 .666 .646 .834 .81
17、4 C Checking Max Height Min .110 .090 .145 .125 .185 .165 .205 .185 .220 .200 .260 .240 .290 .270 .335 .315 .390 .370 .455 .435 .590 .570 J Recess Dia Max Large Min K Recess Max Depth Min .317 .307 .396 .386 .474 .464 .536 .526 .630 .620 .693 .683 .750 .740 .875 .865 1.000 .990 1.125 1.115 1.380 1.3
18、70 .007 .004 .013 .010 .013 .010 .013 .010 .013 .010 .013 .010 .013 .010 .013 .010 .013 .010 .013 .010 .013 .010 J1Recess Dia Max Small Min K Recess Max Depth Min .312 .302 .375 .365 .437 .427 .500 .490 .562 .552 .624 .614 .687 .677 .812 .802 .937 .927 1.062 1.052 1.312 1.302 .007 .003 .013 .006 .01
19、3 .006 .013 .006 .013 .006 .013 .006 .013 .006 .013 .006 .013 .006 .013 .006 .013 .006 Max R Radius Min .031 .018 .031 .018 .031 .018 .031 .018 .031 .018 .031 .018 .031 .018 .031 .018 .062 .031 .062 .031 .062 .031 Max R1Radius Min 2.00 1.50 2.00 1.50 2.00 1.50 2.00 1.50 2.00 1.50 2.00 1.50 3.50 3.00
20、 3.88 3.38 4.62 4.12 6.88 6.38 19.88 19.38 NOTE: Wide slots in top of head located with wide recess on underside of head. Narrow slots in top of head located with narrow recess. 3.3.1 Hydrogen embrittlement. Cadmium plated, Grade 8 bolts specified herein shall be subjected to SAE AMS-QQ-P-416 embrit
21、tlement relief requirement as follows: Time between plating and baking Temperature for baking Time for baking Shall not exceed 4 hours 375F 25F 23 hours minimum In addition, the bolts shall be subjected to the embrittlement relief test of SAE AMS-QQ-P-416. 3.4 Mechanical properties. The mechanical p
22、roperties of the bolts shall meet the requirements as specified in Table II (see 4.4.3 and 4.4.4). Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-45912B 4 TABLE II. Mechanical Properties. Composition Properties Bolt Size - Inches Up to 1” In
23、clusive Over 1” A Tensile Strength PSI Min Proof Load PSI Hardness Rockwell C Range 120,000 85,000 25-34 105,000 74,000 19-30 B Tensile Strength PSI Min Proof Load PSI Hardness Rockwell C Range 150,000 120,000 32-38 150,000 120,000 32-38 3.5 Threads. Threads shall be UNC or UNF, class 2A, as specifi
24、ed on the applicable Military standard in accordance with FED-STD-H28/2. Acceptability of threads shall be in accordance with FED-STD-H28/20, system 22. 3.6 Head. 3.6.1 Head Taper. The taper of the head (angle between one side or sides of the head and the axis of the fastener) shall not exceed 2 deg
25、rees, with the specified width across the flats being the largest dimensions. 3.6.2 Bearing surface. The bearing surface of the head shall be at right angles to the axis of the body within 2 degrees for bolt sizes up to and including one inch and within 1 degree for bolt sizes larger than one inch.
26、The bearing surface of the head shall be concentric with the axis of the body within 3 percent of the maximum width across the flats. The diameter of bearing surface shall be equal to 95 percent of maximum width across flats within plus or minus 5 percent. 4. VERIFICATION 4.1 Responsibility for insp
27、ection. Unless otherwise specified in the contract or purchase order, the supplier is responsible for the performance of all inspection requirements as specified herein. Except as otherwise specified in the contract or order, the supplier may use his own or any other facilities suitable for the perf
28、ormance 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 supplies and services conform to prescribed requirem
29、ents. 4.2 Sampling. 4.2.1 Lot Size. A lot shall consist of all bolts of the same size, composition, protective finish and thread produced under essentially the same conditions and submitted for inspection at one time. 4.2.2 Sampling for examination. A random sample of bolts shall be taken from each
30、lot in accordance with Inspection Level II of ASQ Z1.4. 4.2.3 Sampling for tests. A random sample of bolts shall be taken from each lot in accordance with Table III. Any bolt which fails to pass any of the tests shall be a defective and cause for rejection of the entire lot represented. TABLE III. S
31、ample Size and Acceptance Rejection Number for Test. Lot Size Sample Size AC RE 2 50 2 0 1 51 500 3 0 1 501 35000 5 0 1 35000 over 8 0 1 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-45912B 5 4.3 Examination. The sample bolts of 4.2.2 shall
32、 be examined as specified in Table IV. Any bolt which contains one or more defects shall be a defective. TABLE IV. Classification of Defects. Inspection Categories Defects Method Critical None Major 101 Threads (3.5) *SIE 102 Width across flats (3.2) SIE 103 Undercut depth of head (3.2) SIE 104 Slot
33、 and recess radius of head (3.2) SIE 105 Bearing surface of head (3.6.2) SIE Minor 201 Overall length (3.2) SIE 202 Thread length (3.2) SIE 203 Head height (3.2) SIE 204 Body diameter (3.2) SIE 205 Head taper (3.6.1) SIE 206 Other dimensions (3.2) SIE 207 Protective finish (3.3) Visual *SIE = Standa
34、rd Inspection Equipment 4.4 Tests. 4.4.1 Material. The contractor shall furnish certification that the material complies with the requirements specified in 3.1. 4.4.2 Protective finish. The contractor shall furnish certification that the protective finish conforms to the requirements of the specific
35、ations referenced in 3.3. When required by the procuring agency, the sample bolts shall be tested as specified in the protective finish specifications. 4.4.3 Proof load and tensile strength. The contractor shall furnish certification that the tensile strength and proof load bolts conform to the requ
36、irements specified in 3.4. When required by the procuring agency, the sample bolts specified in Table II shall be tested for hardness (see Table I). The Rockwell hardness shall be measured at mid-radius on a transverse section taken one diameter from the point of the bolt. 4.4.4 Hardness. The contra
37、ctor shall furnish certification that the hardness conforms to the requirements specified in Table I. When required by the procuring agency, the sample bolts specified in Table II shall be tested for hardness (see Table I). The Rockwell hardness shall be measured at mid-radius on a transverse sectio
38、n taken one diameter from the point of the bolt. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-45912B 6 5. PACKAGING 5.1 Packaging. For acquisition purposes, the packaging requirements shall be as specified in the contract or order (see 6.2
39、). When packaging of materiel is to be performed by DoD or in- house contractor personnel, these personnel need to contact the responsible packaging activity to ascertain packaging requirements. Packaging requirements are maintained by the Inventory Control Points packaging activities within the Mil
40、itary Service or Defense Agency, or within the military services system commands. Packaging data retrieval is available from the managing Military Departments or Defense Agencys automated packaging files, CD-ROM products, or by contacting the responsible packaging activity. 6. NOTES (This section co
41、ntains information of a general or explanatory nature that may be helpful, but is not mandatory.) 6.1 Intended use. The bolt covered by this specification is intended for use when a self- locking fastener is needed or where the reduction of fatigue failure is desired. Typical applications include us
42、es as cylinder head bolts, flywheel housing bolts, connecting rod bolts, and as bearing cap screws. The bolt may be used in tapped holes or with nuts. 6.2 Acquisition requirements. Acquisition documents should specify the following: a. Title, number and date of this specification. b. Title, number a
43、nd date of applicable Military standard(s) (see 3.2). c. Applicable MS part number (see 3.2). d. Copies and distribution of test certifications. e. Packaging requirements (see 5.1). 6.3 Subject term (key word) listing. Grade 5 Grade 8 SAE Grade 5 SAE Grade 8 6.4 Description. The bolt covered by this
44、 specification is a one piece, free-spinning type of self-locking bolt. Locking action is provided by a flexible diaphragm which is formed between the slotted segments of the upper part of the bolt head and the circular recess adjacent to the shank in the lower part of the head. This diaphragm acts
45、as a controlled spring element when the head is wrenched against a rigid seat. When used as a bearing cap screw, the material which the head of the bolt seats should be hard enough to form a rigid seat. 6.5 Changes from previous issue. Marginal notations are not used in this revision to identify cha
46、nges with respect to the previous issue due to the extent of the changes. Custodian: Preparing Activity: Army AR DLA - IS Air Force 99 (Project 5306-2013-003) Review Activity: Army - MI NOTE: The activities listed above were interested in this document as of the date of document. Since organizations and responsibilities can change, you should verify the currency of the information above using the ASSIST Online database at https:/assist.dla.mil. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
