Welding distortion is a critical issue as it leads to severe deterioration of structural integrity
of welded work piece and dimensional precision. This study aims at studying the e ects of shielded
metal arc welding (SMAW) parameters on the evolution of mechanical properties, including tensile
strength, impact toughness, and hardness, along with angular distortion on a welded joint from
SA 516 grade 70. Such parameters are analyzed and optimized by employing the Taguchi method
and Grey relational analysis. SA 516 grade 70 is commercially used for fabrication of storage tanks,
boilers and pressure vessels. SMAW is investigated with three levels of root gap, groove angle,
electrode diameter, and pre-heat temperature, which were varied on a butt joint in flat (1 G) position to
determine their e ects on response variables at room temperature. Nine experiments were designed
using a Taguchi L9 orthogonal array, welded according to American Society of Mechanical Engineers
(ASME) section IX, and samples were prepared and tested as per ASTM A 370. The Taguchi method
and Grey relational analysis were employed to observe the most significant parameters and optimal
levels that synergically yield improved responses. Results are validated by conducting confirmatory
experiments that show good agreement with optimum results.