Abstract: A rotary loop taker, for use in a lock-stitch sewing machine, which has a detachable and replaceable hook or loop seizing point. A lug extending downwardly from the main body of the replaceable loop seizing point abuts one end wall of a cut-away portion of the annular frame of the rotary loop taker, and carries a foot that extends inwardly from the annular frame toward the rotatable shaft of the device. The inwardly extending lug foot desirably nests in a notch in the crosswise support member on which the annular frame of the rotary loop taker rests, preferably forming a snug fit with the upper surface of the crosswise support member. The preferable form and dimensions of the loop seizing point and the foot extending inwardly from the downwardly extending lug are disclosed. Ledges formed in the inner wall of the replaceable loop seizing point define the initial portion of the raceway for the bobbin case with which the rotary loop taker is used.