The present work shows the effect of weld penetration levels on the stress level and the fatigue life at the weld joints. Finite element analysis was used to estimate stress pattern of welded joints having different levels of penetration for "Bend Loading" and "Tensile loading" were selected for studies. Specimens with variation in the penetrated throat length between 1.80mm to 0.60 mm were selected. Study has clearly highlighted the corresponding fluctuations observed in the fatigue life with change in weld penetrations. A side loading will be more detrimental than a tensile loading. © 2014 Published by Elsevier Ltd.