Specifies methods of test for determining certain physical and mechanical properties. Owing to the comparatively small cross-section and unusual conditions of performance of this material, special methods have been developed. Some of the tests may not be entirely suitable for thread made from certain synthetic rubbers. Comparisons may only be made on new rubber threads or on that with identical processing histories. The previous history shall be stated in the test report. Replaces the first edition (ISO 2321-1975)