Not to split hairs, I read what it says on worthopedia, but these were (are) actually used to bore holes in cork or rubber stoppers for laboratory equipment, in order to pass glass tubing through the stopper. They're still available from laboratory suppliers. As for cutting cork bottle stoppers, these cut a hole, and thus a plug, of uniform diameter, great if you want a hole to pass tubing through, not so good for a stopper. A cork stopper for a bottle intended to be corked and uncorked would need some degree of taper, to make it easier to start in the opening and to keep it from falling into the bottle when driven tight.
