drill bits

Removing Worn Areas

 

   Drill wear usually begins at the corners of the drill,as a slight rounding,as shown in Figure 1.The cutting edges or lips and the chisel edge begin to wear at the same time .Because of this the surface has no clearance and tends to rub in the hole rather than cut.This wear increases the amount of power needed to force the dulled edge into the work,causing increases the amount of power needed to force the dulled edge into work,causing increased heat generation and faster wear.

   There are two ways to remove worn portions.If the wear is minimal ,lightly regrind the drill point surfaces.For more severe wear-when the drill body is worn back 1/4" or more-cut away the worn areas with an abrasive cutoff wheel,then restorn the original point angle.