A portable multi-function pipe machining apparatus has a plurality of different cutting attachments to provide a portable machining center. The apparatus has a split frame with an inner ring attachable to the outer periphery of a pipe and rotatably mounts an annular tool head which can carry a selected cutting attachment. The annular tool head is driven by one or more drive motors mounted on the inner ring and having driven gears which mesh with an external annular gear on the annular tool head. Each of the cutting attachments mounts a cutting tool for movement along one or more axes with the movement being derived from rotation of the annular tool head and more particularly by rotation of a driven gear associated with the cutting attachment which is rotated by a stationary tool driving gear 22 on the inner ring. The cutting attachments include a cutoff slide for single axis cutting, a cam slide to provide bevel cutting, an X-Y slide for dual axis cutting and a boring bar attachment for boring and which also has a radially movable tool slide to enable movement of a cutting tool both radially and axially of a pipe.