Step drill, the related accuracy in manufacture process is the most important factor for cutting quality. If the precision isn’t controlled well, it will cause hole too rough and even caused reject of work piece. Not only geometry, specification, accuracy, and surface quality, but also the drill volume are important points for the cutting quality of step drill.
During drill process, if the chip groove isn’t well-produced, it would happen wall friction, extrusion, brushed and scratches on its surface. It will cause the bad quality of working surface and obstruction, drill bit stuck, and even broken the drill bit.
BW-90° Step Drill | General-90° Step Drill |
General step drill doesn’t grind a ramp edge in the step part, BW designs a ramp in the step part of drill to make chip removal easier, and also reduce the friction heat caused by the accumulated chips. The first and the second steps are vertical, so it is difficult to cut a gap in these parts during manufacture.