Since the abrasives on the lapping tool are uniformly distributed, the number of abrasives on a circle with radius R is directly proportional to its the circle perimeter and its radius R.

• 因为磨具上磨料是均匀分布的，所以磨具上任一半径R处的磨料微粒数量与其周长正成比，也就是与其半径R成正比。