An overlock stitch is formed by sewing machine (11) (FIG. 1) into a work product (34) and the work product is accelerated away from the sewing machine so as to stretch the thread chain (FIG. 5). The stretched thread chain is cut by cutter (40), and the leading thread chain (43) recoils back toward the hollow chaining tongue (21) and is drawn into the chaining tongue by the stream of air (26) created by vacuum canister (52) (FIG. 6). The next work product draws the leading thread chain out of the hollow chaining tongue and the sewing machine captures the leading thread chain in the stitch. Transfer conveyor (15) (FIG. 1) moves the work product (34) into alignment with everter tube assembly (106), grippers (109) and (110) grip and open one end of the work product (FIGS. 9-14), and air drawn through the everter tube assembly everts the work product. The gripper tube assembly opens along its lower portion (FIG. 16) and drops the work product.