Abrasive member

An abrasive disc for surfacing a workpiece by rotary abrasion under a flow of liquid, said disc being rotatable about a rotation axis in a predetermined direction of rotation and comprising a circular base with a central aperture defining a liquid feed opening and at least two concentric annular series of abrasive segments protruding from said base, said abrasive segments being shaped and arranged in spaced relation to one another so as to form a plurality of arcuate primary channels extending in a generally radial direction and away from the direction of rotation, and at least one concentric circular secondary channel intersecting said primary channels and communicating therewith, each primary channel defining a circular arc and having inner and outer ends intersected respectively by first and second radii generated from said rotation axis, said first and second radii defining therebetween an angle of about 15.degree. to about 45.degree., said at least one secondary channel cooperating with said primary channels to effect substantially complete scavenging of detritus by centrifugal drainage of waste liquid carrying said detritus through both said primary and secondary channels, and wherein each abrasive segment has a planar working surface for abrading contact engagement with said workpiece and a beveled leading edge which extends along a respective one of said primary channels and defines a sloping abrasive surface intersecting a sidewall of said respective primary channel at a predetermined distance above said base to thereby permit said abrasive segments to ride up over surface irregularities protruding from said workpiece during rotation of said disc while maintaining channeling of said waste liquid through said primary channels, whereby said sloping abrasive surface cooperates with said working surface to grind said surface irregularities without causing chipping of said workpiece.