Drill bit made of high-speed steel (4241) with a hardness of 62°HRc (+/-2°) and a cutting angle of 118°. It features straight grinding without cutting correction, suitable for manual sharpening. The diameter tolerance is h8. Right-hand drill bit with N-type spiral, hot forged in rolling mills, offering high flexibility and torsional strength, with polished cutting edges. Cylindrical shank corresponding to the drill diameter. The drill surface is coated with an oxide layer, providing a low coefficient of friction, reducing the risk of chip adhesion to the drill, and increasing drilling performance. Intended for general use, for machining alloys and carbon steels with hardness up to 250Bhn, gray cast iron, non-ferrous metals, and hard plastics. Compliant with DIN-338 standard. Use with coolant is recommended. Diameter: 4.0mm. EAN: 5900171530403