In addition to static loads, fasteners in general are subjected to frequent cyclic loading, including vibrations. Fatigue tests on screws and bolts are most quickly and efficiently performed in a Vibrophore, which can apply cyclic loads with a maximum force of up to 1000 kN in a frequency range up to approx. 285 Hz, using grips designed specifically for screws/bolts and other fasteners. The magnetic drive, which generates controlled resonance in the system, including the specimen, requires minimal power during this test, resulting in highly cost-effective testing. In what are referred to as "H" specimens, the individual joints are subjected to common cyclic loading in tension and compression and the fasteners to a shear effect. H specimen holders designed for this test initially distribute the forces over the entire structure. The bending and resultant loosening of the structure can be measured with an extensometer. With the strain values, the testing machine—once again a Vibrophore—can also provide control of loads or strain, depending on how the test is conducted.