What is 'G' ratio?

The performance of a grinding wheel is generally summarised by quoting the rate of removal of material achieved and the accompanying rate of wear of the wheel. This rate of wear is usually given as the so-called G ratio, which is obtained by dividing the volume of material removed in a particular operation by the volume of the wheel which is worn away. It is a non-dimensional factor calculated by:

volume of workpiece material removed
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 volume of wheel worn