An abrasive roll assembly, comprising: an abrasive roll element configured for milling food grains; an abrasive roll flange; a main shaft; characterized in that the abrasive roll flange is composed of a projecting member formed on its outer periphery, a plurality of through holes configured for mounting said abrasive roll flange to an adjacent flange (11, 21) by means of fasteners, a plurality of projecting lugs formed on its upper portion, with guiding and resting portions (23b, 23a), a plurality of projecting pads arranged with threaded holes for mounting the adjacent flange, and a plurality of guiding members circumferentially spaced apart each other to form a plurality of openings for entry and exit of the adjacent flange; and a supporting plate placed in opposite to the projecting member of said abrasive roll flange, such that said supporting plate is fastened to said abrasive roll flange using fasteners to secure and hold said abrasive roll element, wherein said abrasive roll assembly is insertable into an inserted position from bottom through openings of the adjacent flange (11, 21), said abrasive roll assembly is rotatable in the inserted position into a rotated position, wherein in the rotated position the resting portion of each projecting lug of said abrasive roll flange rests on the surface of each guiding member (2a, 25a) of the adjacent flange (11, 21), and each through hole of said abrasive roll flange is aligned with threaded hole (4a 24a) in each projecting pad (4, 24) of the adjacent flange (11, 21) for mounting said abrasive roll assembly to the adjacent flange (11, 21), wherein both said abrasive roll assembly and the adjacent flange (11, 21) are in centre axial alignment with respect to the main shaft of a milling machine. an abrasive roll element configured for milling food grains; an abrasive roll flange; a main shaft; characterized in that the abrasive roll flange is composed of a projecting member formed on its outer periphery, a plurality of through holes configured for mounting said abrasive roll flange to an adjacent flange (11, 21) by means of fasteners, a plurality of projecting lugs formed on its upper portion, with guiding and resting portions (23b, 23a), a plurality of projecting pads arranged with threaded holes for mounting the adjacent flange, and a plurality of guiding members circumferentially spaced apart each other to form a plurality of openings for entry and exit of the adjacent flange; and a supporting plate placed in opposite to the projecting member of said abrasive roll flange, such that said supporting plate is fastened to said abrasive roll flange using fasteners to secure and hold said abrasive roll element, wherein said abrasive roll assembly is insertable into an inserted position from bottom through openings of the adjacent flange (11, 21), said abrasive roll assembly is rotatable in the inserted position into a rotated position, wherein in the rotated position the resting portion of each projecting lug of said abrasive roll flange rests on the surface of each guiding member (2a, 25a) of the adjacent flange (11, 21), and each through hole of said abrasive roll flange is aligned with threaded hole (4a 24a) in each projecting pad (4, 24) of the adjacent flange (11, 21) for mounting said abrasive roll assembly to the adjacent flange (11, 21), wherein both said abrasive roll assembly and the adjacent flange (11, 21) are in centre axial alignment with respect to the main shaft of a milling machine.