ISO 2321:2006 specifies methods of test for determining general physical and mechanical properties of rubber threads, as well as specific mechanical properties of such threads in contact with fabrics. Owing to the comparatively small cross-section and the unusual conditions of service of this material, certain special methods have been developed.
Some of the tests included in this International Standard may not be entirely suitable for threads made from certain synthetic rubbers (e.g. urethane rubber). These tests are intended for natural or synthetic polyisoprene rubbers.