Abstract: A tool includes a transfer mechanism transferring a fastener row supported in a supply channel in one direction; a cutoff mechanism cutting off a weakened portion of the fastener row supported in the supply channel; a loading member holding one piece of fastener which has been cut off by the cutoff mechanism in a loading portion located in front in a transfer direction of the transfer mechanism, and positioned by abutting against the front-most row of the supply channel; a slide mechanism moving the loading member forward and backward; and a push-in mechanism expanding an outer diameter of a leg portion by pushing a male member of the fastener loaded in the loading member. The cutoff mechanism cuts off the weakened portion of the fastener in a second row, positioned in the next row by counting the fastener in the front-most row as the first row, and in subsequent rows.