![Ring Mandrel. Ring Mandrel.](https://www.langantiques.com/university/wp-content/uploads/elementor/thumbs/Ring-Mandrel-SS-q90xyj1c8s4xyirnvkm3p28s01frofyxwm9trdut8o.jpg)
A mandrel is a rod or arbor that is passed through a hole in a tool (such as a polishing disk, circular saw blade, etc.) and secured in a lathe or other machine.
A mandrel is also a tapered rod, often with marked measurements, used by jewelers for forming rings, bracelets, earrings and other shaped items.