Drilling in hard natural stone or hard tiles
The harder the material, the lower the speed! Hard natural stone or tiles with high pressure, but drill as slowly as possible.
Since the size and sharpness of the transverse cutting edge - which is essentially the center of the drill head - is decisive for the drilling speed, it is recommended to pre-drill with hard materials first with the smallest possible drill bit (4 mm). The "re-drilling" with the desired diameter is then very fast, because now the larger cross-cutting edge of the drill has no resistance.
