1、. . I INCH-POUND I AMENDMENT 1 27 June 1995 MIL-P-256906 MILITARY SPECIFICATION PLASTIC, SHEETS AND FORMED PARTS, MODIFIED ACRYLIC BASE, MONOLITHIC, CRACK PROPAGATION RESISTANT This Amendment forms a part of MIL-P-256906, dated 29 January 1993, and is approved for use by all Departments and Agencies
2、 of the Department of Defense PAGE 5 Table I, under “Limits of permissible deviation“, delete “inch“ and substitute “inches“ PAGE 6 3.7: Delete lines 1 Average value - 10,500“ 4.3.2, line 4: De1ete“ACSTD (Code 6061), Warminster, PA 18974-5000“ and substitute: “Air Vehicle Engineering Department (434
3、100R08), P. O. Box 5152, Warmisnter, PA 18974-5091.“ PAGE 11 4.4.1, line 2: Delete “in figure I“ 4.4.1.1, delete and substitute: “4.4.1.1 Insoection number 1. The starting sheet shall be material approved for listing on the Qualified Products List for MIL-P-8184 (Class 1 or Cl ass 2)“. AMSC N/A 1 of
4、 5 FSC 9330 DISTRIBUTION STATEMENT A. Approved for public release. Distribution is unlimited. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-P-25690B AMENDMENT 1 PAGE 11 (Contd) 4.4.1.2, line 4, after “operation.“, add: “The samples shall be des
5、ignated “for forming“ or “for sized flat sheets“.“ 4.4.1.3: a. Line 1, insert new sentence at start of paragraph. II The test samples selected in 4.4.1.2 designated “for sized flat sheets“ shall be tested to the requirements of Table VI. II a. Line 3, delete: “Blanks are not inspected until after th
6、e forming process. I 4.4.1.4: a. Line 1: Add new sentence at start of paragraph: “Inspection No. 4 shall be conducted after the stretched sheet is cut into blanks and formed into parts. I b. Line 1, delete “new fixture“ and substitute: “newly designed fixture“ cut 4.4.1 Tab1 e in c. Line 5, delete t
7、he third sentence and substitute: “Unless otherwise specified, the forming facility shall generate one set of test data, after part forming, from every fifth stretched sheet that has been into blanks. This shall be accomplished by testing edge cut-outs, other trim areas of a part or by flat forming
8、the sample from 2 designated “for forming“. Tests shall be as specified in VI , except craze resistance which shall be performed as specified 4.4.1.2.“ PAGE 12 Table V: a. Add “Angular deviation - See 3.5.2 L/“ b. Add footnote: “I/ Perform only on sized sheets for direct del i very to the Government
9、 (Inspection #3).“ Table VI: Delete “Angular deviation 3.5.2 4.6.2“ PAGE 15 4.6.6.2.3, line 6, after “inch.“ add: Measurement of the average slow fracture crack length may be by any acceptable means. One suggested method is to use a Bausch W t o 6L “ applied weight (pounds) specimen width (1 inch) s
10、pecimen thickness (inch) outer fiber stress 15000 psi (When no craze occurs, the Government qualifying activity will increase the outer fiber stress to 5500 psi in an attempt to induce craze. This is for data gathering only.) L = Distance from fulcrum to load point (dependent on thickness, 6.5 or 11
11、.5 inch) OlMENSlONS U ANO t are rneasured to the nearest 0.001 inch 2/ Specimen thickness to 0.25 inch = 10 inch specimen length. Specimen thickness 0.25 inch and- over = 15 inch specimen length. TOP VIEW Supports DIMENSIONS IN INCHES FIGURE 7. Crazinq apparatus confiquration. 4 Provided by IHSNot f
12、or ResaleNo reproduction or networking permitted without license from IHS-,-,-. MIL-P-25690B AMENDMENT 1 Custodians: Army - AV Navy - AS Air Force - 11 Preparing Activity: (Project No. 9330-1298) Navy - AS Review Activity: DLA - GS 5 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
