within the paper the writer makes an attempt to evaluate the fatigue lifetime of selected welded joints. It focuses particularly on selected difficulties that accompany deter- state of the fatigue lifetime of welded joints, making an allowance for the stress strength density parameter. bankruptcy 2 describes the welded joint as a pressure concentrator. The kingdom of rigidity and pressure within the notch are defined and theoretical and fatigue coefficients are indicated. The fatigue coef- cient of the notch impression is anticipated at the foundation of fictitious radius within the notch root. bankruptcy three offers a version of fatigue lifestyles evaluate lower than uniaxial tension nation with statistical dealing with of information offered. the hot power version of fatigue existence overview, which rests upon the research of pressure and pressure within the severe airplane, is defined intimately in bankruptcy four. the primary of any such description is gifted within the uniaxial in addition to in - axial kingdom of loading. bankruptcy five comprises the research of checks of 4 ma- rials subjected to varied loadings: cyclic, variable-amplitude with Ga- sian distribution, and variable amplitude with Gaussian distribution and overloading for symmetric and pulsating loading. The research relies at the made up our minds fatigue features for the entire thought of fabrics. bankruptcy 6 exhibits the applying of the version within the fatigue lifestyles evaluation within the advanced kingdom of loading (bending with torsion of flange-tube and tube-tube joints) in accordance with fatigue study of metal and aluminum welded joints conducted in recognized German centres.