Set of ground drills HSS-G, complying with DIN 338, RN, drills are made of high quality high speed steel (HSS), steel is tempered with alloys - Tungsten 9%, Molybdenum 3%, Chrome 4%, Vanadium 1% - for steel drilling up to 900 N / mm. Precise grinding of the helix for maximum performance, accuracy and good centering, thanks to the grinding of the drill tip angle of 118 °, it is possible to drill without the need to use a punch designed for industrial use. [***]