kettakujuliste otstega torn siseavaga toorikute treipinki mutrite abil kinnitamiseks (vt torn; vrd terviktorn, koonustorn, tsangtorn), a mandrel that has a fixed collar at one end and a movable collar threaded at the other end which allows hollow workpieces to be placed between the fixed collar and movable collar, followed by tightening it with a washer nut (see: mandrel; compare: solid mandrel, cone mandrel, collet mandrel)