Diamond crystals can be grown in a wide range of sizes. The size of the diamond crystals used in a cutting tool determines the amount of diamond exposed above the tool's cutting surface. The exposure, or height, of diamond protrusion influences the depth of cut of each crystal, and subsequently, the material removal rate for the cutting tool. Larger crystals and greater diamond protrusion will result in a protrusion will result in a potentially faster material removal rate.
In general, larger crystals are used for cutting softer materials and smaller crystals are used for harder materials.
The mesh size of the diamond also determines the number of crystals per carat. As the mesh increased, the pieces per carat increase. Mesh size is similar to grit size in sand paper. The larger the grit numbers the smaller the size of the abrasive particle.
Selection of the mesh size is critical for tool performance since the number of crystals on the surface of a cutting tool affects the tool's life and power requirements. For instance, changing to a finer mesh size to increase the number of crystals on the cutting edge of a low concentration tool generally increased tool life and power requirements.
In addition to the crystal size, the concentration of diamond used in the cutting segment also determines the number of crystals on the cutting surface. Mesh size and concentration must be balanced for the best performance. Concentration is a measure of the number of diamond particles in a cubic inch of segment and is measured in one of two ways: 100 con=72 carats/cubic or 125 con=75 carats/cubic inch. The two methods of measurement for diamond concentration were established years ago in Europe and the United States. No single measurement standard has ever been agreed upon by the industry.
