This International Standard specifies a test method for determining the transverse flexibility (troughability) of a conveyor belt. It is not suitable or valid for light conveyor belts as described in ISO 21183-1[1].NOTE: The transverse “flexibility” determined by the method described in this International Standard is only indirectly associated with the inverse of flexural modulus as specified in ISO 178[2]. Nor does it take into consideration the differences in “flexibility” as exhibited by three-point and four-point bending, which takes account of the flexural strain and the thickness of the test piece.