1、MIL-S-20561A( OS) 14 March 1974 SUPERSEDING MIL-S-20561 8 January 1952 and Not ice-1 19 November 1973 MILITARY SPECIFICATION SPRING; ESCAPEMENT, CORROSION-RESISTING This specification is approved for use by all Departments and Agencies of the Department of Defense. 1. SCOPE 1.1 The spring covered by
2、 this specification shall cover one class spring for mechanical timing movements, designated: spring, escapement, corrosion-resisting. 2. APPLICABLE DOCUMENTS 2.1 General - The following documents of the issue in effect on the date of invitation for bids or request for proposal, form a part of this
3、specification to the extent specified herein. SPECIFICATIONS Military MIL-P-116 Preservation - Packaging, Methods of STANDARDS Military MIL-STD-129 Marking for Shipment and Storage (Copies of specifications, standards drawings, and publications required by suppliers in connection with specific procu
4、rement functions should be obtained from the procuring activity or as directed by the contracting officer.) 3. . REQUIREMENTS 3.1 The springs furnished under this specification shall be a . product which has been inspected and has passed the first article inspect ion specified herein (see 6.2) . 1 4
5、- I THIS DOCUMENT CONTAINS PAGES. / 7 9, -7 -? Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-L MIL-S-20563A 53 m 4999906 0302870 4 MIL-S-2056lA( OS) 3.2 Material - Springs shall be made from steel produced by the crucible or electric-furnace proces
6、s, using material of high quality. 3.3 Design and construction - The design and construction of springs shall conform to the requirements specified herein. 3.4 Chemical composition - Springs shall be made from steel containing not less than 25 percent nickel and not less than 3 percent chromium. 3.4
7、.1 An analysis of each lot shall be furnished by the contractor, showing the percentage of each element specified. 3.5 Tensile - Finished springs shall be in the cold-rolled condition, and shall have a minimum tensile strength of 200,000 pounds per square inch and a maximum tensile strength of 250,0
8、00 pounds per square inch. 3.6 Ductility - Springs shall meet the ductility test described in paragraph 4.6.2. 3.7 Dimensions - Springs shall conform to the dimensions and per- missible variations as specified in 6.2. 3.8 Workmanship - Springs shall be uniform in quality and temper and shall have a
9、smooth, mirror-like surface finish, free from burrs, scale, and other injurious defects. 4. QUALITY ASSURANCE PROVISIONS 4.1 Responsibility for inspection - Unless otherwise specified in the contract or purchase order, the supplier is responsible for the per- formance of all inspection requirements
10、as specified herein. otherwise specified in the contract or order, the supplier may use his own or any other facilities suitable for the performance of the inspection requirements specified herein, unless disapproved by the Government. The Government reserves the right to perform any of the inspecti
11、ons set forth in the specification where such inspections are deemed necessary to assure supplies and services conform to prescribed requirements. Except as 4.1.1 First article sample - Unless otherwise specified for each contract or order, a representative sample of five springs shall be sub- mitte
12、d to the Government inspector, preserved, packaged, and packed as specified in the contract or order, for first article inspection at an activity designated in the contract or by the Naval Ordnance Systems Command. Further production of the springs by the contractor prior to approval of the contract
13、ing activity of first article samples shall be at the con- tractors risk. of the quantity specified in the contract or order. First article samples accepted will be applied as part 2 !. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-. 4.1.2 Inspecti
14、on lot size - Unless otherwise specified, the number of units of production in an inspection lot will be as determined by the Government inspector. 4.2 Classification of inspection - The inspection and testing of the spring shall be classified as follows: (a) First article inspection - First article
15、 inspection shall consist of examination and tests accomplished on samples which are representative of the production of the item after the award of contract, to determine that the first article samples meet the requirements of this specification, (b) Quality conformance inspection - Quality conform
16、ance inspection shall consist of examination and tests performed on the spring manufactured and submitted for acceptance under contract. 4.3 First article inspection - The first article inspection of the spring shall consist of the visual examination (4.5) and the tests speci- fied under paragraph h
17、eaded Test Methods (4.6). 4.4 - Lot - A lot shall consist of springs made from the same material and made from the same ingot of steel. 4.5 Visual examination - All springs shall be examined by the in- spector. 4.6 Test methods - 4.6.1 Tensile - At last five speciments each 10 inches long and cut 10
18、 feet from the ends of the finished flattened wire, and five specimens from approximately the middle of the flattened wire, shall be submitted by manufacturer for tensile tests. When tests are to be made at the point of delivery, these speciments shall accompany each shipment of springs constituting
19、 an individual lot. 4.6.2 Ductility - At least five springs shall be taken from each lot and shall be bent cold through an angle of 180 degrees around a rod having a diameter two times the thickness of the spring material without showing cracks or fracture on the outside surface. 4.6.3 Dimensional v
20、ariations - At least 25 springs shall be selected from each lot for dimensional measurements. The thickness of the springs shall be measured on a precision measuring machine approved by the Bureau of Standards. 3 Provided by IHSNot for ResaleNo reproduction or networking permitted without license fr
21、om IHS-,-,-4.6.4 Rejection - Springs in which injurious defects are revealed subsequent to acceptance and which fail to comply with the requirements of the contract or purchase order shall be rejected. 5 PREPARATION FOR DELIVERY 5.1 Preservation and packing - Preservation and packaging shall be in a
22、ccordance with MIL-P-116 Method III. packed in a glass or suitable transparent plastic tube. 1000 springs shall be packed in each container. Springs shall be carefully No mre than 5.2 Marking - Marking shall be in accordance with MIL-STD-129. 6. NOTES 6.1 Intended use - The spring covered by this sp
23、ecification is intended to be used for mechanical timing movements for escapement lever. 6.2 Ordering data - Procurement documents should specify the following. (a) Title, number, and date of this specification (b) Dimensions and tolerances required (c) Quantity required (d) When a first article sam
24、ple is not required in contract or order (see 3.1) (e) Level of preservation and packing required if other than 5.1 Preparing activity: Project No. 5360-NO02 Navy - OS *US. GOVERNMENT PRINTLNG OFFICE: 1974-713-162/4292 4 r Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
