Abstract: A hydraulically-driven, self-propelled, in-line sewer tap cutter includes roller bearings mounted to the skids and extending beyond the outer edge of the skids to maintain the frame spaced apart from the sewer pipe and facilitate rolling locomotion of the cutter through the pipe. The roller bearings are positioned so as to align the frame with respect to the bit so that, in use, adequate bit clearance is maintained to cut off taps close to the sidewall of the pipe without jaming the bit at offsets. The specially sized bit includes an integral support shelf formed on the exterior of a generally cylindrical barrel to support cutting teeth mounted extending radially outside the barrel to improve bit life and prevent jamming the bit.