PURPOSE: To smooth the cut end of a sheet material, especially a thick paper product and to avoid getting the cut end irregular by projecting the edge of an opposite blade faced to a rotary blade and by expanding the engagement face in the axial direction with the sheet material.

CONSTITUTION: An opposite blade 5 which is overlapped on a rotary blade 4 and rotates inversely to the rotary blade 4 has a tip 20 projecting to a cutting plane 33 and an engagement face 31 expanding in the axial direction with a paper product. The engagement face 31 is provided in a ring 30 which is integrated with the tip 20 and forms a rear face of the opposite blade 5. The tip 20 is chamfered at the angle 1°-5°, preferably approximately 3° to the cutting plane 33. The radial length of the tip 20 is matched with the thickness of the paper product 2 fed in a scale-shaped arrangement and the cut end of the paper product 2 fed into the scale-shaped arrangement between the rotary blade 4 and the opposite blade 5 is neatly cut without any disturbance.