Narg za vrtanje v luknji je udarna vrtalna vrtalna ploščad, njegova notranja struktura pa se razlikuje od strukture splošnega kamnitega vrta . Njegove mehanizem za porazdelitev plina in odvzemanje bata sta neodvisna, in sicer udarca .. and, through a valve, the piston (hammer) inside the impactor moves back and forth to strike the tail of the drill, causing the drill bit to impact the rock at the bottom of the hole. The high-speed rotation of the impactor inside the hole is achieved by a separate rotating mechanism, namely an electric motor or pneumatic rotating device outside the hole, through a drill rod connected to the rear end of the Udarca . Kamen prah, ki nastane med vrtanjem kamnin
