Systems and methods for forming an opening in a stack

A method of processing a stack that includes at least two layers, the method comprising:

• providing a cutting tool comprising:
• a shank;
• a first portion including at least one of a first coating or a second coating, wherein the first coating at least partially covers the first portion, the first portion having first side-surface diameter that is constant, the first portion including a first end surface, the first end surface being a flat disk, the first end surface covered with the first coating;
• and
• a second portion interposed between the shank and the first portion along a longitudinal symmetry axis of the cutting tool, wherein the first portion and the second portion do not overlap along the longitudinal symmetry axis, wherein the second portion is contiguous with the first portion and the shank wherein the second portion includes the second coating, and wherein the second coating at least partially covers the second portion, wherein all of the second portion has a second side-surface diameter that is constant and that is different from the first side-surface diameter;
• and
• rotating the cutting tool about the longitudinal symmetry axis and urging the cutting tool through the stack parallel to or perpendicular to the longitudinal symmetry axis to form a final opening having a final-opening diameter and extending through the at least two layers, wherein the first portion is smaller than a pilot opening having a pilot-opening dimension and extending through at least one of the at least two layers, the final-opening diameter is substantially equal to or larger than the pilot-opening dimension, and the final opening is substantially coaxial with the pilot opening.