Deformation and force criteria of the limiting-equilibrium state for a plate with an arbitrarily oriented crack under tension and under the influence of hydrogen-containing environment are proposed. The experimental investigations of the limiting-equilibrium state of lamellar specimens made of 09G2S steel with a central inclined crack in hydrogen environment and also in air under tension with different initial crack inclination angles were performed to check the criteria. Under specimen fracture the forces of the crack start were recorded. Experimental data agree well with calculation dependences.