Patent ID: 7926319

Claim:
A mandrel assembly for expanding an opening in a workpiece the mandrel assembly, comprising: a rod comprising a central body, an expansion section having a first longitudinal length, a transition section positioned between the central body and the expansion section, an end section including an enlarged head and a shoulder positioned between the enlarged head and the expansion section; and a slotted outer member movable along the rod, the slotted outer member comprising a tapered section movable from an unexpanded configuration to an expanded configuration, the tapered section including a first end, a second end, and a tapered region extending between the first end and the second end, the first end and the second end defining a second longitudinal length that is longer than the first longitudinal length, the expansion section of the rod sized to keep the tapered section in the expanded configuration when the expansion section of the rod is positioned along a passageway of the slotted outer member as the tapered section expands an opening in a workpiece.