Definition of mandrel
1 a
: a usually tapered or cylindrical axle, spindle, or arbor inserted into a hole in a piece of work to support it during machining
b
: a metal bar that serves as a core around which material (such as metal) may be cast, molded, forged, bent, or otherwise shaped
2
: the shaft and bearings on which a tool (such as a circular saw) is mounted
