A rotary tool containing a core hub with helical groove on its outer surface filled in with continuous abrasive filament formed by folding of a pre-cut abrasive sheet including multiple bristle like straps extending radially from the hub. The method of manufacturing includes the steps of providing a hub, and forming a helical groove with inverted V-shaped cross-section along its cylindrical surface. An abrasive element is wound around the hub so that the folded edge is fed in the V-grove and is buckled inside the groove providing, along with securing it by sufficient pre-tension of the abrasive element, a secure anchoring of the abrasive element through locking of the buckled edge. The abrasive filament is formed from a roll of abrasive cloth as one continuous piece using a cutting operation and is provided with center-line perforations. These perforations assist folding the filament by providing it with discrete and desired flexibility as well as weakening it in such way that it assists the process of folded edge buckling inside the groove during winding and therefore forms a tight anchoring junction with the hub without need for an adhesive.

A surface treatment tool comprising an annular carrier substrate and a plurality of abrasive lamellae connected to the carrier substrate by their narrow sides in a contacting side-by-side arrangement or juxtaposition of their flat sides, at least some of which are fiber fleece lamellae. The carrier substrate is a flexible belt, the ends of which pointing in the longitudinal extension of the belt are connected to one another to form an annular shape. The fiber fleece lamellae are connected to the outward-facing surface of the flexible belt by means of an adhesive connection with flexible material properties in a state in which the lamellae are elastically compressed with respect to their thickness.