The flexural test using DIN EN ISO 178 is a 3-Point-flexural test for the characterization of flexural properties of unreinforced, filled or short fibre reinforced composite thermosettings or thermoplasts (continuous fibre reinforced: see ISO 14125). The test is conducted at constant speed until failure or a given deformation, while load and deformation are monitored. The rectangular and flat samples can be manufactured out of the center piece of standard multi-purpose specimen.

Semi-cristalline polymers are highly sensitive to manufacturing parameters. If quantitative characteristic values are required, those parameters must be recorded carefully.

Please note: Method is applicable only for determination of characteristic values for construction purposes of materials showing linear stress-deformation-behaviour. For materials showing non-linear behaviour the flexural properties can be determined only comparatively. It is advised to use only brittle material which is difficult to measure using tensile tests.