Patent ID: 8881633

Claim:
A cutter wheel for scribing a brittle material substrate, where a V-shaped ridge line part is formed as an edge along the circumferential part of a disk-shaped wheel made of a hard metal or sintered diamond, characterized in that said V-shaped ridge line part is formed of two slanted surfaces which converge as the two slanted surfaces extend outwardly in the direction of the radius, and an outer peripheral part of the ridge line part formed of said two slanted surfaces which converge has microscopic unevenness where the average coarseness Ra along the center line of said unevenness exceeds 0.40 μm, in that said disk-shaped wheel has an outer diameter of 1.0 to 3.0 mm and in that at least one notch is engraved in said ridge line part and notches as that described above are created in the entirety of the periphery of said ridge line part with a pitch of more than 200 μm.