This machine is used to test the fatigue strength of materials and to draw S-N diagram by research institutes, laboratories, material manufacturers and various industries. This is a rotating beam type machine in which load is applied in reversed bending fashion. The standard 8 mm dia specimen is held in special holders at its ends and loaded such that it experiences a uniform bending moment. The specimen is rotated at 4200 rpm by a motor. A complete cycle of reversed stresses in all fibres of the specimen is produced during each revolution. The bending moment is applied with a lever system and can be easily changed by moving a weight over the lever. Total number of revolutions at which the specimen fails are recorded by a mechanical counter. An interlocking system puts off the motor at specimen failure. Machine meets requirements of IS 5075-1969