The Wusthof Wide 10" Fine Diamond Sharpening Steel will actually grind away material from the knife, allowing it to reset the edge. The shape of a diamond sharpening steel produces an optimum edge when sharpening knives. The diamond sharpening steel has a solid stainless steel core and the surface is covered in diamond grains. Diamond sharpening steels have an extremely fine grit that guarantees a smooth, sharp finished edge.