​Special tools are often used in metalworking for drilling thread core holes and screw countersinks. They are also suitable for stepped bores with high surface quality and high dimensional accuracy.
With a step drill, several processing steps can be combined in one and holes with several diameters can be produced in one operation. This makes it possible to save tool space by combining several tools into one special tool. By reducing the number of tools, a significant reduction in the cost of the tools is possible. A decisive advantage of the step drill in contrast to drills with only one diameter is the saving of work steps and thus a significant time saving.