abrasive particles 140 c can be tungsten carbide natural diamond or synthetic diamond the abrasive particles 140 c may be cemented welded or brazed on the side surface 114 or the abrasive particles 140 c may be cast or otherwise incorporated directly into the material of cutter barrel 110 the abrasive particles 140 c may also be formed into an insert by a process such as casting or sintering the insert can then be disposed in a complementary receptacle in side surface 114 embodiments where the abrasive particles 140 c are integral with the side surface 114 provide an additional advantage in that as the side surface 114 wears new abrasive particles will be exposed further it is known in the art to coat diamond grit with a single layer of metal or multiple layers which coatings may be used to bond the aforementioned natural or synthetic diamond diamond particles to side surface 114 or integrally with the material conventionally tungsten carbide of cutter barrel 110 during formation thereof the section of side surface 114 of cutter barrel 110 shown in fig5 d includes a textured or patterned topography or has been roughened at 140 d to provide an irregular surface the texture 140 d can be cast milled or cut into the side surface 114 and may comprise ridges grooves cross hatching bumps divots dimples or holes roughening can be achieved by sandblasting beadblasting shot peening or by welding a hardfacing material to the side surface 114 as will be readily appreciated by those of ordinary skill in the art.