Twist drill made of high-speed steel (4241) with hardness 62°HRc (+/-2°) and with point angle 118°,
straight cut without thinning, good for hand grinding. Diameter tolerance h8.
Spiral dextrorotatory drill, 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 oxide layer, what ensures small friction factor and reduces the danger
of chips sticking to drills, what enlarges drilling capacity.
Suitable for general purposes, for alloy and carbon steels treatment with hardness up to 250Bhn,
for grey cast iron, non-ferrous metals as well as hardened plastics.
According to DIN-338.
It is recommended to use them together with coolant.