Step drill for minimization of burrs when drilling

摘要

A step drill minimizes burrs formed during drilling. Reducing the uncut portion of the work minimized an exit burr, which is formed by the advancing of a drill into a workpiece and increases the bending deformation during the drilling procedure of the workpiece and prolongation of cutting without bending to the end of cutting. The step drill includes a step portion formed at the front edge of the step drill. The step portion has a diameter less than a diameter of the body of the step drill and a step angle of 5 degrees through 130 degrees, and the size of the step is preferably 3% to 20% of the diameter of the body of the step drill.