This European Standard specifies the dimensions, the method of sampling, the preparation of the test specimens and the conditions for performing the tensile test with waisted test specimens in order to determine the tensile energy welding factor. A tensile test with waisted specimens may be used in conjunction with other tests (e.g. bend, tensile, tensile creep, macro...) to assess the performance of welded assemblies, made from thermoplastics materials. The test is applicable to co-axial or co-planar welded assemblies made from thermoplastics materials filled or unfilled, but not reinforced, irrespective of the welding process used. It is not applicable to tubular assemblies with a nominal outside diameter less than 90 mm.