Abstract: A tool for interengaging a pair of element rows in a concealed type slide fastener has a pair of blocks movable toward and away from each other and normally urged apart, and a pair of slider body halves mounted on the blocks, respectively, the slider halves being matable to provide a slider body when the blocks are moved toward each other. An element guide is formed centrally on the bottom surface of a pivotable member operatively connected to the blocks. The pivotable member is movable pivotally into a position in which the element guide and the slider body halves are put together to jointly provide a slider when the blocks are moved toward each other. A motion converting means is provided for converting motion of the blocks into pivotal motion of the pivotable member.