It was obtained that (t s S i 2 )-(σ s /S i ) and (σ d /S i )-(σ′ /S i 3 ) are universal coordinates for presentation of static fatigue and dynamic fatigue data respectively. Usage of these coordinates helps to correctly compare the results of tests of different kinds of fibers (strong and weak) regardless of the initial defect size. Presentation of the dynamic fatigue data for pristine and indented fibers in universal coordinates shows a very similar behavior of both fiber types in spite of their difference in strength.