Twist drills made of high-speed steel (4241) with hardness 64°HRc (+/-2°) and with point angle 118°,
straight cut without thinning, good for hand grinding. Diameter tolerance h8.
Spiral dextrorotatory drills, spiral type N, hot rolled forged, with a high flexibility and torsional strength,
ground edges. Cylindrical shanks matching drills' diameter.
The drills' surface is coated with titanium nitride layer, what ensures small friction factor and reduces
the danger of chips sticking to drills, what enlarges drilling capacity.
Chemical and thermal process of hardening and titanium nitride layer reduce drills' wear
and enlarge durability on inside stresses which appear while using.
Suitable for workshop purposes, for alloy and carbon steels treatment with increased hardness,
malleable cast iron, iron sinters, non-ferrous metals and hardened plastics.
According to DIN-338.
Use it together with coolant.