Abstract: A clamshell lathe that can be utilized to machine or mill a portion of a workpiece such as a tube or pipe, wherein the clamshell lathe is a generally annular device that includes a stationary member and a rotatable member each preferably comprising semi-cylindrical halves that are connected together around the workpiece to be machined. The stationary member includes a bearing channel in which bearings of the rotatable member travel when the rotatable member is activated. In a preferred embodiment, an inner wall of the bearing channel has an angled end portion that is positioned adjacent an angled end portion of the rotatable member.