To well cut a pipe in good balance.

This device is provided with a plurality of roll cutters 8, 10 having a cutting blade 7 in a circumferential part and supported rotatably on one plane to be made approachable and a disc 14 mounted in the sideward of each roll cutter 8, 10 coaxially thereto and having a diameter smaller than the roll cutters 8, 10, and a circumferential part of the disc 14 abuts to the external periphery of a pipe 12 to limit a depth of cut relating to the pipe 12 of the roll cutters 8, 10, so as to form a groove 17 for cutting of uniform depth in the external periphery of the pipe 12.