Abstract: A segment for use in the manufacture of the working portion of an abrasive tool, e.g. a grinding wheel, comprising needle-shaped abrasive particles such as diamond or cubic boron nitride, each having a long axis and a short transverse axis, held in a bonding matrix, a substantial portion of the particles being so aligned that their long axes are substantially normal to the face of the segment which will provide the working face on the tool. The invention further provides a method of making such a segment and a method of making an abrasive tool utilising such segments in which the bonding matrix is only partially set.