AXIS: Imaginary straight line that forms the center line of the drill.
BACK TAPER: Slight decrease in diameter from point towards shank, in the body of the drill.
BODY DIAMETER CLEARANCE: The portion of the land that has been cut away so it will not bind against the walls of the hole.
BODY: Portion of the drill extending from the end of the flutes to the outer corner of the cutting lips.
CHISEL EDGE ANGLE: The angle between the chisel edge and the cutting lips, as viewed from the end of the drill.
CHISEL EDGE CENTRALITY: The measure of variation in the alignment of the chisel edge to the axis. The chisel edge must be central to drill diameter.
CHISEL EDGE: The edge at the end of the web that connects the cutting lips.
CLEARED DIAMETER is measured using a micrometer over the diameter of the cut away portion of the drill lands.
COMMON SHANK TYPES
CUTTING LIP: The cutting edge of a two-flute drill which extends from the chisel edge to the outer edge.
DRILL DIAMETER: The diameter over the margins of the drill measured at the point.
FLUTE LENGTH: The length from the outer corner of the cutting lips at the point (shoulder) to the extreme back end of the flutes.
FLUTES: Grooves formed in the body of the drill to provide cutting lips, to permit removal of chips, and to allow cutting fluid to reach the cutting lips.
HEEL: The trailing edge of the land.
LAND WIDTH: The distance between the leading edge and the heel of the land.
LAND: The outer portion of the body between two adjacent flutes.
LEFT-HAND DRILL: the flute spiral is formed in the opposite direction.
LIP RELIEF ANGLE: The relief angle at the outer corner of the lip.
MARGIN WIDTH: The width of the portion of the drill lands not cut away for clearance.
MARGIN: The narrow portion of the land which is not cut away to provide clearance. It stabilizes the drill in the hole.
MICROMETER: a precision hand-held tool used in our manufacturing departments to measure diameters and thickness to .0001”.
NECK: The section of reduced diameter between the body and the shank of a drill.
OFF LANDS: The measure of variation in the land width from side to side.
OUT-OF-ROUND: Not round.  If caused from centerless grinding, the part will usually have 3 lobes.
OVERALL LENGTH: The length from the extreme end of the shank to the extreme end of the drill point.
PARABOLIC FLUTE DRILL:  open flute with a heavy parallel web and a high helix. These drills are designed to allow deep hole drilling without frequent drill removal to clear chips.

Web at Point and Web at Back are the same thickness:
Point - Split Point
Self centering, requires less thrust in drilling harder metal, breaks up chips

General purpose
POINT ANGLE: The angle of the cutting surfaces on a drill point.
POINT: The cone shaped cutting end of a drill, made from the ends of the land and web.
SECONDARY CUTTING EDGE: The cutting edge formed by the intersection of the face of the notch with the relieved surface of the point, resulting in partial removal of the chisel edge.
SHANK: The part of a drill by which it is held and driven.
WASHOUT: The extreme increase at the end of the flute, formed by the grinding wheel or cutter.
WEB INCREASE: The web thickness increases in thickness towards the shank to enhance the rigidity of the drill.
WEB THICKNESS is measured by using a point micrometer positioned at the point end.
WEB: The central portion of the body that joins the lands.  The extreme end of the web forms the chisel edge on a two-flute drill.