This paper presents is the study and analysis of failure mechanism of non-articular prosthetic foot (SACH) in the region (Bolt Adapter). The tests of mechanical properties and fatigue behavior were carried for material of which the bolt manufacture from it is a region where the failure occurs out and inserted of these properties to the program of engineering analysis (Ansys) to calculate the safety factor of fatigue and stress equivalent (Von-Mises).The results that both, showed the maximum equivalent stress and the minimum safety factor of fatigue are located in bolt at interface region between the adapter and the foot at notch, however, in static case, the effect was on the ground reaction force at toe off phase more than heel strike phase.