Gas Tungsten Arc Welding process is one of the most significant processes of joining two or more pieces of the same or dissimilar materials to achieve complete coalescence using an inconsumable tungsten electrode. The present investigation is an attempt to study the variations in mechanical properties by both changing the base materials with respect to AISI 316 steel i.e. using SA516GR70 as well as annealing ASIS 316 and SA 516GR70 plates initially and then welding to  AISI 316. TIG welded AISI 316 with AISI 316 steel gives most moderate results to be used in required applications with least number of service limitations. Since UTS for TIG welded AISI 316-SA 516 is higher than AISI 316-AISI 316 but it has a lower value of impact strength than AISI 316-AISI 316 welds. AISI 316-SA516GR70 weldment has a number of limitations when applicable in service conditions. An attempt to increase the properties by initially annealing can be of worth when the welding parameters could be considered(e.g. welding current, groove design, filler etc), hence mechanical characterization infers that AISI316-AISI316(annealed) can be thought of importance when the prevailing conditions are moderate enough and the weldment is quite feasible to bear such service conditions where as  AISI316-SA516(annealed) proves to be of less importance from service point of view due to formation of complex grain structure near the fusion boundary and heat affected zone on the 516 annealed side of the weldment.