Underwater weld repairs on aluminum alloy piping systems and/or installations would be a particular advantage. UWFSW trials were carried out on Al 6063 alloy using a milling machine. Tool rotational speeds rangs about 480–1800 rpm, with a speed of traverse of rpm. Various mechanistic measurements were utilized to explore the mechanical characteristics of welded joints, comprehensive disruptive tests (tensile test and hardness test). The outcome display that Al 6063 pipe can be welded using the UWFSW process with an utmost welding competence of 92.7% in terms of (UTS), while the speed of rotational is 1800 rpm, and the travels speed is 4 rpm.