5.1 The procedures in Test Methods D2969 for the determination of the properties of steel tire cord and related materials are considered satisfactory for acceptance testing of commercial shipments of such products because the procedures are the best available and have been used extensively in the trade. When a purchaser frequently uses a specific supplier, it is recommended that the two parties investigate the methods to determine if there is any bias between their two laboratories as directed in 5.1.1.
5.1.1 In case of a dispute arising from differences in reported test results when using this test method for acceptance testing of commercial shipments, the purchaser and the supplier shall conduct comparative tests to determine if there is a statistical bias between their laboratories. Competent statistical assistance is recommended for the investigation of bias. As a minimum, the two parties shall take a group of test specimens that are as homogeneous as possible and that are from a lot of material of the type in question. Test specimens shall then be randomly assigned in equal numbers to each laboratory for testing. The average results from the two laboratories shall be compared using the appropriate statistical analysis and an acceptable probability level chosen by the two parties before testing is begun. If bias is found, either its cause must be found and corrected or the purchaser and the supplier must agree to interpret future test results with consideration to the known bias.
5.2 The significance and use of particular properties are discussed in the appropriate sections.
Область применения1.1 These test methods cover the testing of cords made from steel that are specifically designed for use in the reinforcement of pneumatic tires. By agreement, these test methods can be used to test similar cords or filaments used for reinforcing other rubber products. The steel cords shall be wound on spools or beams. The steel cords can also be woven into fabric, in which case they must be removed from the fabric prior to testing.
Note 1: For other methods of testing tire cords and tire cord fabrics, refer to Methods D885, Test Methods D1871, Specifications D122, and Test Methods D2692 and D2970/D2970M. For tolerances on tire cords and tire cord fabrics, refer to Specifications D122 and Methods D885.
1.2 These test methods include test procedures only; they do not establish specifications or tolerances.
1.3 This test method includes the following sections:
Subject
Section
Adhesion of Steel Cords and Filaments to Elastomers
16
Brass Coating Composition and Mass
14, 15
Breaking Force (Strength)
10
Construction
12
Data Form for Reporting Test Results
Appendix X1
Elongation at Break
10
Elongation Between Defined Forces (EDF)
11
Flare
8
Lay
12
Linear Density
9
Visual Appearance
8
Nomenclature System
Annex A1
Residual Torsions
8
Straightness
8
Thickness and Out-of-Roundness
13
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. See 14.3 and Note 11.
1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.