1、A-A-52410 m 9999974 OL4L953 93T m Beneficial comments, recommendations, additions, deletions clarifications, etc. and any other data which may improve this document should be sent by letter to: METRIC A-A-52410(AT) February 9, 1993 SUPERSEDING MIL-B-45326C(AT) 2 June 1989 COMMERCIAL ITEM DESCRIPTION
2、 BOOT, DUST AND MOISTURE SEAL: HYDRAULIC BRAKE CYLINDER, SYNTHETIC RUBBER The General Services Administration has authorized the use of this commercial item description (CID) as a replacement for MIL-B-45326C(AT) which is canceled. 1.0 Abstract. This CID covers brake boots used in covering the open
3、ends of wheel and master cylinders in hydraulic brake systems of automobiles, trucks, and other wheeled vehicles employing hydraulic brake fluid of the nonpetroleum base type. Brake boots covered by this specification are intended for use as protective devices against dirt and moisture. 2.0 Salient
4、characteristics. 2.1 Materials. Materials shall be a synthetic, non-oil resistant rubber compound conforming to ASTM D2000 M4AA 510 A13B13 or ASTM D2000 M4AA 610 A13B13. The use of recovered material made in compliance with regulatory requirements is acceptable pro-.-iding that all requirements of t
5、his CID are met (see 5.4). 2.2 Design and construction. Boots shall be of molded construction and shall conform to the dimensions specified in the applicable drawings (see 5.2). 2.3 Performance. 2.3.1 Durometer hardness. The durometer hardness of the boot shall be as specified in ASTM D2000 M4AA 510
6、 A13B13 or ASTM D2000 M4AA 610 A13B13 for the applicable rubber compound. Boots shall be tested for durometer hardness in accordance with ASTM D2240. I I AMSC NIA FSC 2530 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. Licensed by Information Handling ServicesA-A-5
7、2410 9999974 0141954 876 2.3.2 Volume change. When tested for volume change the volume of test specimen shall neither increase by more than 20 percent (%) nor decrease by more than 5%. After testing, the durometer hardness shali not increase by more than 5 points nor decrease by more than 10 points.
8、 Boots shall be tested for volume change by immersion in liquids conforming to SAE 51703. The test fluid temperature shall be 121 + 3 degrees Celsius (OC). The time of immersion shall be 70 - + 1/4 hours. area. The change in volume of the specimen due to immersion shall be calculated as follows: Spe
9、cimen shall be approximately 6.45 square centimeters in Change in (W3 - W4) - (W1 - W2) volume, percent, = x 100 (W1 - W3) Where: Wq is the weight of the specimen in air before immersion, grams. W2 is the weight of the specimen in distilled water before immersion, W3 is the weight of the specimen in
10、 air after immersion, grams. W4 is the weight of the specimen in distilled water after immersion, grams. grams. 2.3.3 Heat stroking. Boots shall show no evidence of flex cracks, extending through the wall thickness and fit around cylinder and push rod, after being tested for heat stroking in an oven
11、 of the type described in ASTM D573. To conduct the test, two boots shall be mounted on the stroking device. The push rods shall then be cycled at the rate of 1000 + 100 strokes per hour for 120,000 cycles. Stroke length shall be 80% of the maximum stroke for master cylinders and 5 millimeters for w
12、heel cylinders. 1OC. No oil shall contact the boots during stroking. The ambient air temperature shall be 70 - + 2.3.4 Low temperature flexibility. Boots shall show no evidence of damage, or cracks after being tested for low temperature flexibility. To conduct this test, two boots shall be mounted o
13、n a fixture, placed in a cold chamber, and held at a temperature of minus 18.3 + 2OC for not less than 70 hours. The boots shall be so mounted that relative motion between each boot and push rod will not occur. The push rods shall then be actuated through the maximum stroke, for which the cylinder w
14、as assigned, for a total of 10 cycles. 2-3.5 Heat resistance. After oven aging, the durometer hardness of the boot shall not be greater than 15 points higher or not more than 5 points lower than the initial durometer hardness. The rubber, after cooling, shall not be tacky and there shall be no crack
15、ing when folded. Two boots shall be tested. The test shall consist of suspending one of the two boots in the oven for 70 + 114 hours at 100 - + 3OC and suspending the other boot in the oven for 24 + 114 hour at 121 - + 3OC. 2.3.6 Ozone resistance. Boots shall exhibit no evidence of cracking or ruptu
16、re under seven power magnification after being exposed to ozone concentration test. Two boots shall be assembled on a hydraulic cylinder or equivalent which will provide a 12 to 15% stretch in both the boot-head and push-rod mounting areas. The boots shall then be conditioned in an ozone-free atmosp
17、here at room temperature for not more than 45 minutes. Samples shall A circulating oven described in ASTM D573 shall be provided. 2 Licensed by Information Handling ServicesA-A-5 2 4 LO m 9999974 OL43955 702 m A-A-52410(AT) then be placed in an ozone chamber with the ozone concentration maintained a
18、t 50 - + 5 parts per 100,000,000 parts of air by volume,. at a temperature of 38 + l0C, for a period of 168 + 1/2 hours. and rupture under seven power magnification. 2.4 Identification and marking. Unless otherwise specified (see 5.2), identification and marking shall be legible and permanent and sh
19、all include as a minimum the manufacturers CAGE code, the part number, and the symbol “OZ“. The boots shall be examined daily for cracking 2.5 Workmanship. Dust boots shall be free of blisters, cracks and embedded 3.0 Quality assurance provisions. 3.1 Responsj.bility for inspection. The contractor i
20、s responsible for the foreign material. performance of all inspections (examinations and testsj. 3.2 Contractor certification. The contractor shall certify and maintain substantiating evidence that the product offered meets the salient characteristics of this commercial item description and that the
21、 product conforms to the producers own drawings, specifications, standards, and quality assurance practices. Items with known defects shall not be submitted or Government acceptance. conformance prior to the first delivery and thereafter as may be otherwise provided for under the provisions of the c
22、ontract. The Government reserves the right to require proof of such 4.0 Preservation, packaging, packing, labeling, and marking. Preservation, packaging, packing, labeling, and marking for the desired level shall be as specified in the contract (see 5.2). 5.0 Notes. a (This section contains informat
23、ion of a general or explanatory nature that may be helpful but is not mandatory.) 5.1 Addresses for obtaining copies of referenced documents. 5.1.1 Non-Government publications. ASTM D573 “Standard Test Method for Rubber-Deterioration in an Air Oven“; ASTM D2000 “Standard Classification system for Ru
24、bber Products in Automotive Applications“; ASTM 02240-91 “Standard Test Method for Rubber Property-Durometer Hardness“ are available from the American Society for Testing and Materials, 1916 Race Street, Philadelphia, PA 19103; SAE 51703-91 “Motor Vehicle Brake Fluid, Standards“; are available from
25、the Society of Automotive Engineers, 400 Commonwealth Drive, Warrendale, PA 15096. 5.2 Ordering data. Acquisition documents must specify the following: a. Title, number, and date of this commercial item description. b. Issue of the Department of Defense Index of Specifications and Standards (DODISS)
26、 to be cited in the solicitation, and if required, the specific issue of individual documents referenced (see 5.1). c. Title, number, and revision letter of the applicable engineering drawing (see 2.2). d. Identification marking required (see 2.4). e. The part number (see 2.4). f. Selection of appli
27、cable levels of preservation, packaging, packing, labeling and marking (see 4). 3 Licensed by Information Handling ServicesA-A-52410 9999974 O14195b b49 e O 5.3 Cross-reference. Boots conforming to this CID are substitutable with boots conforming to MIL-B-45326C(AT). interchangeable/ 5.4 Regulatory requirements. The offeror/contractor i encouraged to u recovered materials in accordance with Public Law 94-580 to maximum extent practicable. Custodian: Army - AT Army - MI Review activities: DLA - CS 4 Preparing activity: Army - AT (Project 2530-0345) Licensed by Information Handling Services
