Diamond grinding wheels

Machine

Optimal working conditions for grinding wheels depend on their peripheral speed, which for diamond is around 25-30 m/s and 50-60 m/s for CBN. Therefore, the diameter of the grinding wheel is determined by the characteristics of the machine.

Machines should have the tightest possible clearances since diamond, which is a very hard and tough material, is nonetheless also very fragile. If for any reason the machine does not rotate sufficiently rapidly, this deficiency should be compensated by increasing the concentration of superabrasive on the wheel, and vice versa.

Concentration

Concentration is the quantity of superabrasive, measured in carats per cubic centimetre (ct/cm3), contained on the grinding wheel's abrasive surface.

Equivalent quantity of superabrasive used

The concentration chosen will depend on the work surface area and the finish required. If the work surface area is very large, then low concentrations are used, and vice versa. For grinding wheels with coarse grains, concentrations slightly greater than those for fine grains are used.

Superabrasive grain size

Grain choice is determined by the grade of finish required on the surface to be worked.

Coarse grain are used for very rough grinding when there is a lot of material to remove, and fine grains are used for work when less material needs to be removed, but the final finish quality is much higher.

Depending on the grit size, very fine finishes can be achieved, even going so far as to polish material and achieve mirror-quality finishes.

Bond

The bond is, in many ways, grinding wheel manufacturers' secret ingredient. The bonding agent's main function is to agglomerate the superabrasive grains and fix them to the wheel. Bonding agent choice is very important, because manufacturers need to use the most suitable agent that will retain the grains while they still have an edge, and then release them when they become blunt so that new grains appear.

Usually, bonding agents are: