1 flange with short shaft (loaded by belt drive),  2 bolt,  3 pick-up disk,  4 clamp set,  5 driving shaft,  6 shaft with maximum crack (flange joint with 2 load-bearing bolts),  7 shaft with small crack (flange joint with 5 load-bearing bolts),  8 shaft with no crack (flange joint with 6 load-bearing bolts)