Drill for rock or concrete or earth - has drilling head consisting of individual points of hard metal soldered into head

摘要

The drill is for rock, concrete or earth. It has a drilling head (1) consisting of individual points (2,3,4,) of hard metal. The points (2,3,4,) have stepped or conical tapered seating surfaces (5) which are soldered in recesses in the drill head (1). The angle of the conical seating is between 40 and 60 deg. USE/ADVANTAGE - In drilling large diameter holes the danger of breakage is diminished.