A friction stir welding tool comprises a cylindrical shank, a shoulder portion disposed at a distal end of the shank, a pin extending from the shoulder, a cutting insert mounted within a concave portion at the distal end of the shank, and a scribe cutter mounted at a distal end of the cutting insert. The cutting insert extends distally through a channel in the pine, and the scribe cutter extends from a distal end surface of the pin in an offset position. The distal end surface of the pin is perpendicular to a longitudinal axis of the shank.