1、NIL-STD-LZ57A ND W 77777LL UOhL3L L m 5-3qa3 MIL-STD-i 257A 24 January 1967 SUPERSEDING SA-STD-109 6 October 1962 MIL-STO-1257 28 April 1965 MILITARY STANDARD RADIOGRAPHIC AND VISUAL SOUNDNESS REQUIREMENTS FOR COBALT-CHROMIUM ALLOY LINERS (FOR SMALL ARMS BARRELS) n III- FSC B5 -., c 7- , _I THIS DOC
2、UMENT CONTAINS I( n. PAGES. kL 7. (finish-machined) 2m mer 12 Visual standard for surface defects; caliber .50 liner (finish-machined) iii 13 U Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-flIL-STD-1257A ND U 7777733 0063834 7 m MIL -STD - 12 5 7A
3、 24 January 1967 1. SCOPE 1.1 This standard establishes radiographic and visual standards and standard inspect$on procedures for use in acceptance inspection for soundness of cobalt-chromium alloy liner castings and finish-machined liners for small arms barrels. 2. REFERENCED DOCUMENTS 2.1 The issue
4、s of the following documents in effect on date of invi- tation for bids form a part of this standard to the extent specified herein. SPECIFICATIONS FEDERAL L-F-350 - Film, Radiographic, Industrial. MILITARY MIL4 -13358 - Cobalt-Chromium Alloy Castings (For Barrel Tube Liners). STANDARDS MILITARY MIL
5、-sm-453 - Inspection, Radiographic. 3. DEFINITIONS (Not applicable) 4. GENERAL REQUIREMENTS 4.1 CASTINGS. 4.1.1 Castings shall be radiographed and inspected in accordance with MIL-C-13358 or as specified in the contract and in accordance with MIL-S1D-453 except that non-film radiographic techniques
6、are not permitted. 1 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-STD-1257A 24 January 1967 4.1.2 Penetrameters shall be as specified in MIL-STD-453, or a step wedge type approved by the procuring activity may be used. penetrameters used shall
7、 be identified in the inspection records. The type of 4.1.3 Unless otherwise specified, radiographs shall show the image of at least two holes (quality level 2-2T) and the outer edge of the penetrame ter . 4.1.4 Laboratories and personnel performing radiographic inspection shall meet the requirement
8、s of MiL-STD-453. 4.1.5 Identification markings. Each casting shall be identified by a serial number or letter of test. marked on the casting with waxed crayon or other semi-permanent method and shall be correlated with lead identification numerals, letters, or both which will appear distinctly on t
9、he film. This identification shall be clearly 4.1.6 Acceptance standards. 4.-1.6.1 Acceptance standards for radiographic inspection of liner castings consist of radiographic negatives of liner castings for 7.62-MM and Caliber .50 machineguns, which show borderline acceptable conditions for the type
10、of defect covered. (See Standards 1 thru 6.) Two views of the liner casting are shown on the standard negatives; one view at ninety degrees to the other view. The borderline acceptable conditions for the type of defect are indicated by circles marked on the standard negatives. 4.1.7 Defects . 4.1.7.
11、1 The defects illustrated in this standard include internal shrinkage (shrink), gas-holes, and non-metallic inclusions (dirt) and may be recognized on the radiographic negative by the following descriptions: 4.1.7.1.1 Internal shrinkage. Appears as dendritic, filamentary, (See Standards 1 subsequent
12、 reports and radiographs shall be furnished the procuring activity in accordance with the inspection and records provision of MIL-STD-453 or as specified in the contract. L I _I *- Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-. MIL-STD-3257A ND W
13、7777733 OOhL3 4 W MIL-STD- 12 57A 2 4 January 1 9 6 7 5.2 FINISH-MACHINED LINERS. 5.2.1 Examination. Visual examination for surface defects of finish- machined liners shall be performed by the contractor in accordance with the provisions of this standard. any of the examinations set forth herein whe
14、re such exarriinations are deemed necessary to assure supplies and services conform to the prescribed requirements. The Government reserves the right to perform 5.2.1.1 The lot size for visual examination shall be in accordance with the criteria specified in the contract. 5.2.2 Sampling. Sampling sh
15、all be performed in accordance with the criteria specified in the contract. However, each casting which was provisionally accepted during radiographic examination (see 5.1.3.2) shall be examined for surface defects in the finish-machined condition. 5.2.3 Determination of acceptability. 5.2.3.1 The a
16、cceptability of finish-machined liners shall be determined by comparing the visible surface defects with the applicable standards, figure 1 or 2. 5.2.3.2 Any finish-machined liners which fail to meet the applicable visual standards shall be rejected. (Copies of specifications, standards, drawings, a
17、nd publications required by contractors in connection with specific procurement functions should be obtained from the procuring agency or as directed by the contracting officer.) (Copies of this standard for military use may be obtained as indicated in the foreword to the Index of Military Specifica
18、tions and Standards.) (Copies of this standard may be obtained for other than official use by individuals, firms, and contractors from the Superintendent of Documents, U. S. Government Printing Office, Washington 25, D. C.) Custodians : Army - WC Navy - Bu Wep Air Force - WRAMA Preparng activity: Ar
19、my - WC Project No. 1005-0384 o 5 7 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-r- MIL-STD-li257A ND H 7777711 0061837 6 H . *_ . . _ _ . . -_. . .- Li Y s lW7 r4 i I I Provided by IHSNot for ResaleNo reproduction or networking permitted without
20、license from IHS-,-,-_ NIL-STD-1257A ND 7777733 0063840 2 - . .*I _. . . . .r .i ._ . :- . - . .“ . ,. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-. . - .r- t I 1 1 i MIL-STD-1257A ND W 7779731 0063843 4 W Y 1 67 ! J rt -.l. Provided by IHSNot fo
21、r ResaleNo reproduction or networking permitted without license from IHS-,-,-I -2- MIL-STD-3257A ND 9977933 0063842 b - i i I :. 1. I i t i I :-, t R Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-STD-3257A ND H 77779LL 0063843 H ! t I Iw w rl,
22、4 4 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-L MIL-STD-1257A ND W 7777711 OObLLILI T W _ - _- Y I O -Y=- .- - Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-T I I I I -r I I l I I I I I I I I
23、I $ I a O rl rl (11 al P rl rl o 5“ g u o al w al a $4 O .rl k al U c .ri al o0 (drl WP $4 *rl 7m v1 .rl P ( rrt al rl P (d U a al o o (d al P U O c I-! rl (d %; ka alal cal u0 ox al (do alc Od url id as aiCo v1 O aal au oa hV d(d rcal affl U .rl u Ud al4 E7 (da .rl 5u MIL-STD - 12 5 7A 2 4 January 1 9 6 7 aal s mu al .rl c U. S. GOVERNMENT PRINTING OFFICE : 1966 O - 792-223 n Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
