1.1 This test method covers the determination of dynamic full reversed fatigue properties of plastics in flexure. This method is applicable to rigid and semi-rigid plastics. Stress and strain levels are below the proportional limit of the material where the strains and stresses are relatively elastic. Three-point or four-point bending systems are used to determine these properties. 1.2 This test method can be used with two procedures: 1.2.1 Procedure A, designed for materials that use three-point loading systems to determine flexural strength. Three-point loading system is used for this procedure. 1.2.2 Procedure B, designed for materials that use four-point loading systems to determine flexural strength. Four-point loading system is used for this procedure. 1.3 Comparative tests can be run in accordance with either procedure, provided that the procedure is found satisfactory for the material being tested. 1.4 The values stated in SI units are to be regarded as the standard. The values provided in parentheses are for information only. 1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this