Abstract: The present invention relates to a spherical bearing seat cutter machine for cutting large spherical bearing seats, such as, those used in equipment which is installed in power-generating stations and other like plants. The apparatus includes a pair of spaced supports, each of which is adapted to be connected to a workpiece. A drive shaft is rotatably mounted in the supports. A rotary drive is connected to the drive shaft for rotating the drive shaft in the supports. A cutter assembly is mounted on the drive shaft, which cutter assembly includes a cutting tool which travels on an arcuate track for cutting a spherical bearing seat. The cutter assembly includes a counterweight opposite the cutting tool. An arcuate drive is connected to the cutting tool for moving the cutting tool along the arcuate track as the drive shaft rotates. The machine also includes an axial drive for moving the cutter assembly axially along the drive shaft for making a straight or cylindrical cut.