Bobbin Friction Stir Welding (BFSW) is a new application of Friction Stir Welding (FSW) that can be used to join materials together with little to no axial forces. This eliminates the need of a backplate or anvil needed to apply counter pressure against the tool. The applications of BFSW are growing every day. This new technology is helping the automotive industry and many other industries join materials more effectively and efficiently. This technology can be used to join materials with high strength to weight ratios to make cars lighter to increase fuel efficiency. This will also greatly reduce the cost of current joining technologies.The purpose of this research is to prove the feasibility of augmenting a BFSW tool with cutters to join enclosed castings while simultaneously removing ribs and variations in thickness by (1) penetrating a BFSW tool into the material away from an edge; (2) removing any inconsistencies in the material thickness while maintaining a weld; and (3) removing a BFSW tool from the casting away from an edge leaving a clean exit hole without destroying either the casting or the tool.