1、Comments, suggestions, or questions on this document should be addressed to Defense Logistics Agency Aviation VEB, 8000 Jefferson Davis Highway, Richmond, VA 23297-5616, or e-mailed to STDZNMGTdla.mil. Since contact information can change, you may want to verify the currency of this address informat
2、ion using the ASSIST Online database at https:/assist.dla.mil/. AMSC N/A FSC 1670 INCH-POUND MIL-DTL-6458G 9 July 2012 SUPERSEDING MIL-DTL-6458F 18 April 2008 DETAIL SPECIFICATION CHAIN ASSEMBLIES, SINGLE LEG, AIRCRAFT CARGO TIE DOWN This specification is approved for use by all Departments and Agen
3、cies of the Department of Defense. 1. SCOPE 1.1 Scope. This specification covers two types of flight safety critical aircraft cargo tie down chain assemblies. The chains described in this specification are to be used in conjunction with the tie down tensioners described in MIL-DTL-25959, where the T
4、ype I chain assembly is to be used with the Type I (styles A and B) and Type III tie down tensioners, and the Type II chain assembly is to be used with the Type II (styles A and B) and Type IV tie down tensioners. 1.2 Classification. Chain assemblies covered by this specification are of the followin
5、g types: Type I - 10,000 pound capacity Type II - 25,000 pound capacity 1.3 Part or identifying number (PIN). The PIN to be used for chain assemblies acquired to this specification is created as follows: M 6458-X Type: 1 - Type I - Max. Weight 8 (lbs.) Cancel use code (LKU) 2 - Type II - Max. Weight
6、 24 (lbs.) Cancel use code (LKU) 3- Type I - Max. Weight 6.5 (lbs.) for new weight requirement 4- Type II - Max. Weight 19 (lbs.) for new weight requirement Specification number Prefix for military specification Provided by IHSNot for ResaleNo reproduction or networking permitted without license fro
7、m IHS-,-,-MIL-DTL-6458G 2 2. APPLICABLE DOCUMENTS 2.1 General. The documents listed in this section are specified in sections 3 and 4 of this specification. This section does not include documents cited in other sections of this specification or recommended for additional information or as examples.
8、 While every effort has been made to ensure the completeness of this list, document users are cautioned that they must meet all specified requirements documents cited in sections 3 and 4 of this specification, whether or not they are listed. 2.2 Government documents. 2.2.1 Specification, standards a
9、nd handbooks. The following specifications, standards, and handbooks 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. DEPARTMENT OF DEFENSE STANDARDS MIL-STD-130 - Identification Ma
10、rking of U.S. Military Property. MIL-STD-810 - Environmental Engineering Considerations and Laboratory Tests. MIL-STD-889 - Dissimilar Metals. (Copies of these documents are available at https:/assist.dla.mil/quicksearch or https:/assist.dla.mil or from the Standardization Documents Order Desk, 700
11、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 otherwise specified, the issues of these documents are those cited in the solicitation or contract. ASTM INTERNATIONA
12、L ASTM A 304 - Standard Specification for Carbon and Alloy Steel Bars Subject to End-Quench Hardenability Requirements. ASTM A 322 - Standard Specification for Steel Bars, Alloy, Standard Grades. ASTM A 108 - Standard Specification for Steel Bars, Carbon and Alloy, Cold-Finished. ASTM C150/C150M- St
13、andard Specification for Portland Cement ASTM C 778 - Standard Specification for Standard Sand (Copies of these standards may be found online at http:/www.astm.org/ or from: ASTM International, 100 Barr Harbor Drive, P.O. Box 700C, West Conshohocken PA 19428-2959.) Provided by IHSNot for ResaleNo re
14、production or networking permitted without license from IHS-,-,-MIL-DTL-6458G 3 AMERICAN WELDING SOCIETY AWS B1.11 - Guide for the Visual Examination of Welds. (Copies of these standards may be found online at http:/www.aws.org/ or from American Welding Society, 550 N.W. LeJeune Road, P.O. Box 35104
15、0, Miami FL 33135.) SOCIETY OF AUTOMOTIVE ENGINEERS, INC. SAE-AMS-H-6875 - Heat Treatment of Steel Raw Materials. (Copies of these standards may be found online at: http:/www.sae.org/ or from Society of Automotive Engineers, Inc., 400 Commonwealth Drive, Warrendale, PA 15096-0001.) AMERICAN NATIONAL
16、 STANDARDS INSTITUTE ANSI / ASQ Z1.4 - Sampling Procedures and Tables for Inspection by Attributes (Copies of these standards may be found online at www.ansi.org or from American National Standards Institutes, 25 West 43rdStreet, New York, NY 10036.) 2.4 Order of precedence. Unless otherwise noted h
17、erein or in the contract, in the event of 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 been obtained. 3. REQUIREMEN
18、TS 3.1 First article. When specified (see 6.2), a sample shall be subjected to first article inspection in accordance with 4.3. 3.2 Materials. 3.2.1 Metals. Metals shall be suitably treated to resist corrosion due to fuels, salt fog (spray), or atmospheric conditions likely to be met in storage or n
19、ormal service. The chain assembly shall be made of alloy steel conforming to ASTM A 304, ASTM A 322, ASTM A 108 or equivalent, and heat treated to produce a chain of high tensile strength with resistance to impact loads. 3.2.2 Heat treatment. Heat treatment of steel parts shall be in accordance with
20、 SAE-AMS-H-6875. 3.2.3 Dissimilar metals. Unless suitably protected against electrolytic corrosion, dissimilar metals shall not be used in intimate contact with each other. Dissimilar metals are defined in MIL-STD-889. Provided by IHSNot for ResaleNo reproduction or networking permitted without lice
21、nse from IHS-,-,-MIL-DTL-6458G 4 3.3 Chain assembly. The chain assembly shall be of the welded-link type consisting of a length of chain, a coupling link, and a hook constructed so that it forms a single unit without detachable parts. The weld on each link shall not interfere with attaching that lin
22、k to or removing it from the adjuster tumble block (i.e. no sharp edges extending beyond links). Each link shall be capable of being attached to and removed from the adjuster tumble block, with a load applied, without the use of special tools. The chain assembly shall meet the strength, weight and d
23、imensional requirements specified on figure 1. 3.4 Hook. The hook shall be a grab type with dimensions as shown in figure 2 and shall engage chain links of the size specified on figure 1. The hook shall be designed to permit fastening of one chain assembly to another of the same type to form a singl
24、e branch system of two chain assemblies for extension purposes. The hooks shall meet the design strength requirements of the chain assemblies and shall not reduce the strength of the chain assembly into which it has been attached. The hook must fully engage the attaching chain link with the chain li
25、nk in contact with radius R as specified on figure 2 and without interference from adjoining links. 3.5 Recycled, recovered, or environmentally preferable materials. Recycled, recovered, or environmentally preferable materials should be used to the maximum extent possible, provided that the material
26、 meets or exceeds the operational and maintenance requirements, and promotes economically advantageous life cycle costs. 3.6 Performance. 3.6.1 Proof load. When tested as specified (see 4.5.2 and 4.5.8), the Type I chain assembly shall be capable of withstanding proof loads of 10,000 pounds, and the
27、 Type II chain assembly shall be capable of withstanding proof loads of 25,000 pounds. There shall be no evidence of failure, permanent deformation or subsequent malfunction of parts. 3.6.2 Ultimate load. When tested as specified (see 4.5.3), the Type I chain assembly shall be capable of withstandin
28、g ultimate loads of 14,100 pounds and the Type II chain assembly shall be capable of withstanding ultimate loads of 35,250 pounds. Deformation, without rupture or visible cracks, will be permitted provided the chain remains flexible after removing the applied load. 3.6.3 Environmental characteristic
29、s. The chain assembly shall be fully operational and show no evidence of rust or corrosion when subjected to the salt fog (spray) testing (see 4.5.5) and the sand and dust testing (see 4.5.7). Any evidence of rust or corrosion will require an additional proof load test as specified in 4.5.8. 3.7 Int
30、erchangeability. All parts having the same manufacturers part number shall be functionally and dimensionally interchangeable. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-6458G 5 Chain assembly Type Design Strength (lbs.) Max. Weight (lbs.
31、) Min. Length (inches) I 14,100 6.5 108 II 35,250 19 108 Coupling link dimensions (inches) Type Inside length - A Width Bar size diameter - D Weld diameter E Outside - B Inside - C Nominal Min. Max. Min. Max. Min. Max. Nominal Min. Max. Nominal Min. Max. I 1.020 0.961 1.079 1.220 0.453 0.354 0.346 0
32、.362 0.394 II 1.496 1.488 1.503 1.889 0.669 0.519 0.511 0.519 0.560 Chain link dimensions (inches) Type Inside length - A Width Bar size diameter - D Weld diameter E Outside - B Inside - C Nominal Min. Max. Min. Max. Min. Max. Nominal Min. Max. Nominal Min. Max. I 0.923 0.923 0.941 0.975 0.374 0.394
33、 0.281 0.275 0.281 0.307 II 1.456 1.417 1.503 1.515 0.535 0.472 0.464 0.472 0.502 Note: The “B“ dimension includes the weld dimension “E“. Figure 1. Chain assembly strength, weight and dimensional requirements. LDEABCAASection A-ACoupling linkProvided by IHSNot for ResaleNo reproduction or networkin
34、g permitted without license from IHS-,-,-MIL-DTL-6458G 6 Type A B C D E F G H I J K R 12I 2.266 1.047 0.844 1.359 0.650 2.250 1.031 0.359 2.657 0.515 0.375 0.188 50 105 II 3.425 1.368 1.368 1.968 1.102 3.780 1.673 0.590 3.661 0.866 0.610 0.305 75 105 Tolerances: A maximum; B, C, D, E, F, G and I app
35、roximate; H + 0.04/- 0 inch; J and K + 0.028/- 0.028; 1and 2approximate. Figure 2. Grab hook dimensional requirements. 3.8 Finish. All steel parts with the exception of corrosion resistant steel shall be treated with a metallic-type coating that will provide a cathodic protective coating to the base
36、 metal. This protective coating shall not crack, peel, or flake during normal usage and shall withstand any adverse conditions to which the chain assembly will be subjected in accordance with this specification. The protective coating shall in no way prevent compliance with the performance requireme
37、nts of this specification. DECBAKR=K/2FGIJH12Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-6458G 7 3.9 Identification of product. The chain assembly shall be identified by a 2 dimensional data matrix applied to the hook portion assembly in
38、such a manner as to minimize the potential for abrasion. The data matrix element shall be a machine-readable information (MRI) marking that is fully readable by either a fixed or portable reader, and when read by the reader will provide as a minimum in a clear text display, part number, national sto
39、ck number (NSN), contract number and manufacturers commercial and government entity (CAGE) code. The information need not be in a Unique Identification (UID) format unless serialization is required. The data matrix shall be affixed with a quality grade and size as deemed appropriate by the manufactu
40、rer to provide the required information and show no signs of corrosion or abrasion after being subjected to the salt fog (see 4.5.5), abrasion (see 4.5.6) and the sand and dust testing (see 4.5.7). (NOTE: Users of this specification should reference MIL-STD-130 for an in-depth understanding of ident
41、ification marking and the MRI technology.) 3.10 Workmanship. The chain assembly shall be free from injurious imperfections that may impair appearance and serviceability. The welded chain shall be free from all surface discontinuities in accordance with AWS B1.11. Dimensions and tolerances not specif
42、ied shall be consistent with standard industry practice. 4. VERIFICATION 4.1 Classification of inspections. The inspection requirements specified herein are classified as follows: a. First article inspection (see 4.3). b. Conformance inspection (see 4.4). 4.2 Test conditions. Unless otherwise specif
43、ied, all tests required by this specification shall be made at standard ambient conditions in accordance with MIL-STD-810. 4.3 First article inspection. 4.3.1 First article sample. The first article test sample shall consist of two chain assemblies of the type required that are representative of the
44、 production chain assemblies. The test samples shall undergo all of the tests specified in section 4.5 at a laboratory designated by the manufacturer under the supervision of the procuring activity. 4.4 Conformance inspection. Conformance inspection shall be in accordance with ANSI / ASQ Z1.4 and sh
45、all consist of the individual tests (see 4.4.1) for each unit produced, as well as the periodic sampling tests (see 4.4.2) if required by the procuring activity (see 6.2). a. Individual tests. b. Periodic sampling tests. 4.4.1 Individual tests. Each chain assembly shall be subjected to the examinati
46、on of product and proof load test (see 4.5.1 and 4.5.2). Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-6458G 8 4.4.2 Periodic sampling tests. The periodic sampling tests shall be in addition to the individual tests and shall consist of the
47、tests specified in 4.5.3 and 4.5.4. The manufacturer shall select the type of sampling plan in accordance with ANSI /ASQ Z1.4. The sample size shall be selected in accordance with general inspection level I. 4.4.3 Rejection and retest. Failure of any item being tested and inspected will postpone fin
48、al acceptance until the cause of rejection has been investigated and corrected for the entire contract quantity. Other than marking and minor workmanship issues as determined by the Government, items that have been tested and failed shall be discarded and not be reworked or delivered as part of any
49、end item lot. If a new production lot is required, the lot will be tested using a tightened sample size in accordance with general inspection level II of ANSI / ASQ Z1.4. 4.5 Test methods. 4.5.1 Examination of product. Each chain assembly shall be inspected to determine compliance with the requirements specified herein with respect
