mandrel
A round object used as an aid for shaping a material, e.g. shaping or enlarging a ring, or bending or enlarging a pipe without creasing or kinking it.
The coil springs were manufactured by winding the heated steel strip direct out of the furnace on to a mandrel of the requisite size.
A tool or component of a tool that guides, grips or clamps something, such as a workpiece to be machined, a machining tool or a part while it is moved.
This socket forms the starting point of the piercing operation, enabling the mandrel to center itself on the work.
Where it comes from
From French mandrin, probably from Vulgar Latin *mamphurinum, from Latin mamphur (“a bow drill”), ultimately from Oscan or Ancient Greek μαννοφόρον (mannophóron, “wearing a collar”), from μανά (maná, “collar”) + φέρω (phérō, “to bear”); first element cognate with Latin monile (“collar”).
Adapted from the Wiktionary entry mandrel (CC BY-SA 4.0).