A tool assembly for a surgical stapling device, comprising: a first jaw having a first surface; a second jaw having a second surface facing the first surface, the second jaw movable in relation to the first jaw between an open position and a clamped position; a drive member having a distal end portion, and an approximation drive assembly, the tool assembly characterized in that: the second jaw defining first and second threaded bores (201, 202); the distal end portion of the drive member supporting a rack having a first side and a second side, the drive member movable from a retracted position to an advanced position; and the approximation drive assembly including a first lead screw received within the first threaded bore, a second lead screw received within the second threaded bore, a first pinion supported on the first lead screw, and a second pinion supported on the second lead screw, the first pinion engaging the first side of the rack and the second pinion engaging the second side of the rack, wherein the first lead screw and the second lead screw are each rotatably secured to the first jaw, wherein movement of the drive member from the retracted position toward the advanced position advances the rack to rotate the first pinion and the second pinion, and wherein rotating the first pinion rotates the first lead screw within the first threaded bore and rotating the second pinion rotates the second lead screw within the second threaded bore to move the second jaw in relation to the first jaw from the open position to the clamped position. a first jaw having a first surface; a second jaw having a second surface facing the first surface, the second jaw movable in relation to the first jaw between an open position and a clamped position; a drive member having a distal end portion, and an approximation drive assembly, the tool assembly characterized in that: the second jaw defining first and second threaded bores (201, 202); the distal end portion of the drive member supporting a rack having a first side and a second side, the drive member movable from a retracted position to an advanced position; and the approximation drive assembly including a first lead screw received within the first threaded bore, a second lead screw received within the second threaded bore, a first pinion supported on the first lead screw, and a second pinion supported on the second lead screw, the first pinion engaging the first side of the rack and the second pinion engaging the second side of the rack, wherein the first lead screw and the second lead screw are each rotatably secured to the first jaw, the second jaw defining first and second threaded bores (201, 202); the distal end portion of the drive member supporting a rack having a first side and a second side, the drive member movable from a retracted position to an advanced position; and the approximation drive assembly including a first lead screw received within the first threaded bore, a second lead screw received within the second threaded bore, a first pinion supported on the first lead screw, and a second pinion supported on the second lead screw, the first pinion engaging the first side of the rack and the second pinion engaging the second side of the rack, wherein the first lead screw and the second lead screw are each rotatably secured to the first jaw, wherein movement of the drive member from the retracted position toward the advanced position advances the rack to rotate the first pinion and the second pinion, and wherein rotating the first pinion rotates the first lead screw within the first threaded bore and rotating the second pinion rotates the second lead screw within the second threaded bore to move the second jaw in relation to the first jaw from the open position to the clamped position.