Abstract: A device for cutting pipe internally includes an annular cutter head having a plurality of circumferentially spaced openings therethrough, a stepped drive shaft extending from the cutter head and having a longitudinal bore therethrough and an adapter at the distal end of the drive shaft for connection to a rotary drive member. A frustoconical mandrel has a threaded rod extending from one end thereof through the shaft bore to the distal end of the shaft where it threadably engages a nut held stationary with respect to the drive shaft. The mandrel has a plurality of inverted T-shaped slots extending along the frustoconical side thereof, each slot receiving the T-shaped projection on a cutter body. Each cutter body has a rotatable cutter wheel mounted thereon, the wheel being adapted to project through a corresponding opening in the cutter head. Rotation of the drive shaft by the rotary drive member will cause rotation of the mandrel and the threaded rod.