A turntable for an optical storage drive comprises a fitting member (4) consisting of a stationary yoke and a movable yoke (40) carrying a sliding cam (40a). A plurality of inwardly directed, equally spaced, resiliently deformable fingers (12) extend from a disc setting surface (3) at a location radially inward from the periphery of the turntable. In the rest position, there is no contact between the sliding cam (40a) and the fingers (12). However, after a disc (101) has been positioned on the turntable, the movable yoke is lifted and the sliding cam (40a) provides a locking effect on the fingers (12), thereby improving the centering force thereof.