PURPOSE: To increase a connecting area so as to firmly connect a band streak to a chip possible to achieve heavy cutting by drilling between slits a notched part arranging in its peripheral edge many notched holes and pressurizing the chip to infiltrate into each notched hole.

CONSTITUTION: A band streak plate 1 forms with an equal space slits 2 respectively providing a notched part 3 therebetween drilling many notched holes 6 in a peripheral edge part 5. This notched hole 6 is notched in only the one part of its true roundness and formed so as to prevent a chip 4, infiltrating by pressure, from falling off. And the chip 4 is a mixture with a metal dust, containing abrasive grains of diamond, serving as a binding agent, and the chip 4 is formed in rectangular parllelopiped shape previously larger in the thickness than that of the band streak plate 1, protruding to the upper by about the half from the notch part 3 with an insertion fitted part almost agreeing with the notched part 3. Next the chip 4 is fitted to the notched part 3, and the chip 4, when it is pressurized and heated from both side surfaces, is thinned while covering an outer side peripheral edge part 5 of the notched part 3. Thus, the chip 4 is guided to infiltrate into each hole 6, sintered and connected in a part where the notched part 3 is adapted to the chip 4.