Friction stir welding is a better alternative for fusion welding of aluminum and magnesium alloys. This technique is being explored for various new materials and configurations in last two decades. But the developments concentrated on longitudinal welding in which welding is performed in parallel direction to the joint. Due to this, welding the components with smaller width that are smaller than shoulder diameter of welding tool is not possible. In this study, an innovative welding method is developed and proved by experiments for welding smaller width components. In the new method, welding is carried out perpendicular to the conventional joint direction. This development enables to use friction stir welding to weld components of short width in the order of few mm. Friction stir welding of AE42 magnesium alloy and AA2024 aluminum alloy of 4 mm thick, 50 mm width and 100 mm length were carried out for the developmental work. Welding was carried out to join two such plates to join them on 50 mm side to obtain 200 mm long components after welding. Penetration of welding was maintained as 90% of the thickness. Joint strength as per standard ASTM E8 was evaluated and found as minimum 70-80% of parent metal, and superior to parent metal for some parameters for both the alloys. The distance between the passes in the multi pass welding was varied and its effect on results was analyzed. Resultant joint strength, microstructure, hardness were analyzed and compared in detail. Copyright © 2013 ASM International® All rights reserved.