Abstract: A grinding wheel assembly having a throw-away type hub construction in which the insert member imbedded in the molded abrasive disk hub portion is provided with a plurality of circumferentially spaced grooves in the juncture between the cylindrical section and annular flange section thereof. The die cast metallic shaft engaging member is provided with mating tongues or projections shaped to engage axially within the grooves when the extremity of the cylindrical portion of the die cast member is swaged into engagement with the adjacent face of the hub portion when in assembled relation therewith.