The purpose of the Aerator Tine is to create small holes in the surface of the lawn, either by removing a core of dirt or by driving a spike into the lawn to push the surrounding dirt away. Often about 1/2" wide, 4" deep, and spaced 6" apart, these holes allow air, water, and nutrients to more easily reach the roots of the grass and promote better growth. Replacing an aerator tine is a common repair task that will improve the performance of your aerator.