To suppress the generation of noise in a cutting work of a bolt, and to easily finish the work in a short period of time.

On an outer periphery of a flange connecting part F, two semi-annular frames 1 and 1 are provided and inner peripheral cutting edges 2 are respectively provided on the inner peripheral sides of the frames 1. Both ends of the frames 1 and 1 are respectively fastened by choke bolts 3 and nuts 4. Then, the fastening force of the choke bolts 3 is adjusted to allow a bolt B to be cut to abut on the inner peripheral cutting edges 2. Under this state, when a handle 5 provided in the frames 1 is held to rotate this device on an axis of the flange connecting part F, a slit is formed in the bolt B. The choke bolts 3 are repeatedly fastened to form the slits in the bolt B and completely cut the bolt B. Since the cutting work is manually carried out, noise is low and the work is carried out at night. Since a plurality of bolts B are allowed to abut on the inner peripheral cutting edges 2 and cut at the same time, the cutting work is completed in a short period of time.