1.1 This International Standard specifies methods for the determination of the breaking force and elongation at break of textile yarns taken from packages. Four methods are given: – A: manual; specimens are taken directly from conditioned packages; – B: automatic; specimens are taken directly from conditioned packages; – C: manual; relaxed test skeins are used after conditioning; – D: manual; specimens are used after wetting. 1.2 Method C is used in cases of dispute regarding elongation at break of the yarn. NOTE – Methods A, B and C are expected to give the same results for yarn strength, but Method C might give somewhat truer (and higher) values of elongation than A or B. Method D is likely to give results differing, for both breaking force and elongation at break, from those obtained by methods A, B or C. 1.3 This International Standard specifies methods using constant rate of specimen extension (CRE) tensile testers. Testing on the now obsolete constant rate of travel (CRT) and constant rate of loading (CRL) instruments is covered, for information, in Annex A, in recognition of the fact that these instruments are still in use and can be used by agreement. 1.4 This International Standard applies to all types of yarns, except glass, elastomeric, aramid, high molecular polyethylene (HMPE), ultra high molecular polyethylene (UHMPE), ceramic and carbon yarns and polyolefin tape. NOTE – A method for the testing of glass yarns is given in ISO 3341. 1.5 This International Standard is applicable to yarns from packages but can be applied to yarns extracted from fabrics, subject to agreement between the interested parties. 1.6 This International Standard is intended for the single-end (single-strand) testing of yarns. NOTE – The skein method of testing is given in ISO 6939.