FIELD: mining.
SUBSTANCE: drilling bit comprises a head that has a front surface comprising an end surface configured to extend from it a plurality of cutting surfaces, a sizing part surrounding the end surface. The end surface forms the most forward end of the head and has an outer edge. The sizing part has an inner edge. A transition zone that is not circular when viewed along the longitudinal axis passes in the direction of the drilling bit longitudinal axis between the end surface outer edge and the sizing part inner edge. The entire end surface, designed to extend from it a plurality of cutting surfaces, is not flat, so that the center of the end surface is axially in front of the outer edge of the end surface.
EFFECT: increased service life of the bit.
15 cl, 5 dwg
