Abstract: A tube cutter unit in one embodiment with self centering tube cutting and supporting jaws is rotated by a power drive unit for cutting a tube. The jaws are free to engage the tube without spring load. After engagement with the tube, a relatively high load spring is deflected to induce a tube cutting force on the jaws. The amount of deflection of the spring determines the depth of cut. A separate tool operating socket is also rotatably driven with the cutter unit. The cutter unit is coupled to the drive by a one way clutch. The drive is reversible to selective operate the cutter unit. In a second embodiment, a cutter unit without self centering jaws is separated from a power drive for manually operation and connected to the power drive for power operation. The power operator is reversible for selectively operating the cutter unit. The latter cutter unit also does not provide a spring load on the jaws except for providing a cutting force after the jaws engage the tube being cut.