A portable tool for use in axially cutting and squaring ends of tubes includes a main tool body within which is rotatably mounted a tool shaft having a cutting tool attached at one end thereof, a tube receiving and clamping unit for retaining an end portion of a tube to be worked upon, a mechanism for shifting the tool shaft relative to the main tool body so that the cutting tool can progressively engage the end portion of the tube and a power drive unit for rotating the tool shaft. The tube receiving and clamping unit is provided with a plurality of circumferentially spaced ports which provides viewing access to a cutting zone, enables adjustments to or changing of the cutting tool and permits chips cut from the tube to be readily removed from within the tool. The shifting mechanism includes a camming arrangement that ensures smooth shifting of the tool shaft and which is designed to minimize the ingress of foreign matter into the tool. In addition, the power drive unit can be advantageously secured on opposing sides of the main tool body.