PURPOSE: To minimize the waste caused in the conversion of an abrasive disc by integrally holding a plurality of split abrasive sheet pieces having at least three projecting ends to constitute an abrading wheel.

CONSTITUTION: A residual material 106, which is left after a circular abrasive disc is die-punched from a sheet, is formed with slits 108 so that this residual material 106 can be divided into small split sheet pieces 110. The resulting split sheet piece 110 has three projecting ends 112, and a through hole 114 is formed in the center of the split sheet piece 110, as occasion demands, to facilitate the mounting on a core bar 112. A plurality of such split sheet pieces 110 are shifted by a prescribed phase and layered, and a bolt 120 is inserted to the through-hole 114 and screwed to the core bar 112 to integrally fix the split sheet pieces 110, whereby a desired abrading wheel 118 can be completed.