Abstract: Apparatus and method for measuring circumferential surface dimensions of workpieces. A circular table is mounted with its upper surface in a horizontal plane for both rotational and reciprocal vertical movement. A plurality of through slots in the table extend radially with respect to its central axis of rotation. A like plurality of gripper fingers having both vertical and angularly disposed edges are affixed to a common cable for radial movement with respect to the table axis. When the table is in its upper position the fingers are positioned below corresponding ones of the slots, and when in the lower position portions of the fingers extend through the slots. As the fingers are moved toward the workpiece it is engaged by and rides up the angularly disposed edges until it abuts the vertical edges of the fingers. While the workpiece is supported above the table surface, one or more wheels rotatable about vertical axes are moved to engage the surface to be measured.