PURPOSE: To make it possible to safely, efficiently and exactly remove the required length by cutting off the slot rod of an optical cable from the front surface in a longitudinal direction with a rotary blade having a columnar shape and providing the rotary blade with a cavity to insert the tension member exposed in the central part of rotation of the rotary blade.

CONSTITUTION: The rotary blade 10 has three cutting blades 11 to 13 which are formed to the construction having recesses while twisting toward the center. The respective cutting blades 11 to 13 have cutting edges (a), (b) varying in angles respectively to the slot rod. A nut-like threaded part 14 for mounting to the bolt-like revolving rod of a drill is formed at the other end. The slot rod is removed while the slot rod is embraced by rotating such rotary blade 10. In addition, the swarf of the slot rod is discharged by rotation. The tension member exposed by the removal of the slot rod is inserted into the cavity 15 formed in the central part of rotation of the rotary blade 10. The flank part of a cylindrical rotary blade cover is provided with a window for discharging the swarf.