FIELD: mining.
SUBSTANCE: group of inventions relates to a drilling bit for percussive drilling of mine rock and to its use. A drilling bit includes a drilling head, a connecting coupling having the first end and connected to the drilling head with the first end, a bore passing axially through the connecting coupling from its second end to the first end and provided with an internal cylindrical female thread for connection to the corresponding external cylindrical male thread of a drilling stem, and an impact surface to be borne against an end surface of the drilling stem, which is made at the bore bottom and passes perpendicular to the longitudinal axis of the drilling bit. Each cross section of the bore between the impact surface and some part of the bore, where the female thread has a full profile, has a surface area that is less than the cross sectional area of the bore on the bore part where the female thread has a full profile.
EFFECT: increase of strength and elimination of weakness of a bit connecting coupling.
13 cl, 3 dwg
