PERFORMANCE EVALUATION OF MODIFIED DRILLS

INTRODUCTION 1.1. Fundamentals of drilling Drilling is one of the most widely used methods for making holes. The cutting tool in this case is a drill with which a hole can be made from the solid or the diameter of a previously drilled hole can be increased (enlarging holes). The primary cutting motion in drilling is rotary a straight-line feed motion is used, in the drilling process. Both of these motions are imparted to the drill simultaneously. The drill is clamped in the spindle which rotates it and feeds it down into the workpiece which is clamped stationary on the table.