The grain size – As large as possible, as small as necessary

The grain size of the grinding material has a decisive influence on the process flow and

final result when grinding. For example, reducing the grain size increases the number of active cutters, and the roughness of the surface created is improved independently from the work-piece

speed. The grain size therefore has a decisive influence on the ease of grinding and the life expectancy of the grinding tool. Although there are some exceptions, it can be stated in general that the ease of grinding as well as the life expectancy are increased as the grain size increases. For this reason, the coarsest possible grain size should always be selected.

The classification and designation of grain sizes is based on the ISO standard 6106-1979, the FEPA standard, and DIN 848 and use two designation systems:

• The metric designation, which is based on the mesh size of the screens (EU)

• The number of screen openings per inch of the corresponding screens (mesh, USA)