Abstract: A mechanism for automatically engaging a slider upon a pair of slide fastener chains having teeth, includes a curved track which is supplied with sliders from a hopper. One slider at a time moves to a position in front of a carrier on which is mounted a pivotable lever. The first slider from the hopper is held in position by a horizontal retractable pin extending to the track. The lever has a foot which clamps the end slider from the hopper. Jaws carrying a pair of slide fastener chains move to the clamped slider which is moved by the carrier toward the jaws. The adjacent end of each chain is inserted into the body of the clamped slider as the carrier moves forwardly. The carrier continues to move forwardly with the lever and clamped slider causing the teeth of the chains to close. The jaws and lever then release the new assembly of slider and two engaged chains, and other jaws grasp the new slide fastener assembly and move it to another processing station.