Abstract: In the manufacture of a brush-shaped grindstone (3), embedding holes (310) are formed in a grinding element holding surface (311) of a holder (31) in mutually separated positions. A base end side of a plurality of wire-shaped grinding elements (32), formed such that a composite yarn composed of inorganic filaments is impregnated and hardened with a resin, is aligned, and rod assemblies (320) are thereafter formed by fixing the base end side of the plurality of wire-shaped grinding elements (32) with adhesive (71) in holes (60) of a die material (6), which is formed to have substantially the same size as the embedding holes (310) of the holder (31). The rod assemblies (320) are thereafter embedded in the embedding holes (310) of the holder (32), and fixed with adhesive (72). Whereby, removing burrs from a precision work component, performing polishing, and the like can be carried out with good efficiency and high precision.

Abstract: An abrasive includes an alumina-based fiber bound by a matrix resin which contains diamond abrasive grains therein, and a diamond abrasive grain layer provided on the surface of the bound fiber. The abrasive is formed into, for example, a flat plate having a thickness in a range of 0.45 to 1.2 mm, and the diamond abrasive grain layer is provided on at least any one of opposite surfaces of the bound fiber. Flat filaments having a ratio of a long axis to a short axis of the cross-sectional shape thereof in a range of 1.3 to 1.8 are used for the alumina-based fiber.

Abstract: A material adapted for the preparation of a working tool contains long fiberglass arranged in the form of an entwined yarn and at least one thermosettable resin containing abrasive grains dispersed therein, which impregnates the entwined fiberglass yarn. Upon shaping and curing, a working tool is readily formed from this material in the form of any of a rotor, a stick or other desired shape.