To gain a better understanding of the fatigue characteristics of components like valves and pipes in hydrogen gas atmosphere, fatigue tests are performed at a pressure of 10 MPa. The compression-tension tests (R=-1) were conducted with a test frequency of 1 Hz and a triangular waveform. The smooth round specimens are 5 mm in diameter and have no drilling hole or notch for crack initiation. The surface is electropolished to remove the work hardening layer and to enable surface observations by replica method. In the low cycle fatigue regime, the time for crack propagation is large. Hence, the short crack behaviour is investigated to identify the propagation mechanisms and to gain information on how the propagation might be decelerated. Three materials are analysed: Two austenitic stainless steels with different nickel content (very similar to AISI 304L) and a martensitic stainless steel (1.4313). As a result of the specific austenite stability, significant differences in the strain induced austenite‑martensite transformation could be observed. In austenite cracks initiate predominantly along slip bands and propagate by planar and cross slip. In Martensite areas with parallel short cracks were initiated. Most of these cracks stopped propagating reaching the next grain boundary.